EFFECT OF $EWML fifiO‘W‘EH REGULAYORS ON GROWTH AND DEVELOPMENT OF SAINTPAULIA Thesis for flu: Degree of DH. D. MICHEGAN STATE UNIVERSITY I Evan Paul Roberts 1958 TH ESIS This is to certify that the thesis entitled EFFECT OF SEVERAL GROWTH REGULATORS ON GROWTH AND DEVELOPMENT OF SAINTPAULIA Date 0-169 presented by EVAN PAUL ROBERTS has been accepted towards fulfillment of the requirements for _Hl._.lldegree in Mt” e JM @1141 lag/9&3 Major professor May 12, 1958 *— “fl“ w am~ n-‘lr- m..- -am“ ”—7.: _ ,.__.. —..... ,-- EFFECT OF SEVERAL GROWTH REGULATORS ON GROWTH AND DEVELOPMENT OF SAINTPAULIA By EVAN PAUL ROBERTS AN ABSTRACT Submitted to the School for Advanced Graduate Studies of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements f for the degree of DOC TOR OF PHILOSOPHY Department of Horticulture EVAN PAUL ROBERTS ABSTRACT To determine the effects of various growth regulators on Saintpaulia, the African violet, two cultivars were used: ‘ ‘Star Girl Seedling' and 'Queen's Cushion'. Four hundred and eighty plants were set up in a randomized and replicated design and grown at 65'F night temperature on two benches in the Plant Science greenhouse, Michigan State University. Treated groups received three spray applications each of 100 parts per million of maleic hydrazide, indoleacetic acid, gibberellic acid, and 25 parts per million of triiodobenzoic acid at three-week intervals. Data were recorded and analyzed statistically for rooting response of leaf-petiole cut- I tings, lasting quality of flowers, number of flowers and peduncles, and pollen germination. Graphs were made from growth data determined from the measurements of maximum diameters of the rosettes. Observations on the morphological changes of the plant organs were noted. Rooting response of leaf-petiole cuttings in the control group for each cultivar were as good, and in most cases better, than those from the chemical treated groups for each cultivar. Treatments producing the rooted cuttings arranged in descending order for the largest number of cut- tings rooted to the smallest were: control, maleic hydrazide, indoleacetic acid, triiodobenzoic acid, and gibberellic acid. Pollen germination for cultivar 'Star Girl Seedling' indicated that EVAN PAUL ROBERTS ABSTRACT - 2 , chemical treatment of plants inhibited pollen germination. Pollen of the culti- var 'Queen's Cushion' was not used since it is a cultivar with low pollen pro- duction. The number of flowers was significantly greater in the gibberellic acid treated groups of cultivar 'Queen's Cushion‘ than in the untreated and chemical treated groups. The number of flowers was not significantly great- er for gibberellic acid treated plants of cultivar 'Star Girl Seedling' than those of the untreated plants. However, the gibberellic acid treated plants produced a significantly greater number of flowers than the flowers from plants treated with indoleacetic acid and triiodobenzoic acid. The number of peduncles was significantly greater for the gibberellic acid treated group than for all others. This was true for each cultivar. The untreated flowers of cultivar 'Queen's Cushion' lasted signi- ficantly longer than those in any other group, while indoleacetic acid was most effective for making the flowers last longer in cultivar 'Star Girl Seed- ling'. - Formative modifications resulting from chemical treatments were apparent only in the 100 parts per million gibberellic acid treated groups of each cultivar. Modifications common to both cultivars included: changes in leaf shape; elongation of petioles, peduncles, and leaf blades; an upward EVAN PAUL ROBERTS ABSTRACT - 3 movement of leaves toward the vertical axis of the plant. Modifications specific to cultivar 'Star Girl Seedling‘ were: changes in style position and shape; separation of anthers; and a tendency toward greater production of peloric flowers. EFFECT OF SEVERAL GROWTH REGULATORS ON GROWTH AND DEVELOPMENT OF SAINTPAULIA By EVAN PAUL ROBERTS A THESIS Submitted to the School for Advanced Graduate Studies of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Horticulture 1958 FIGURE 1-4. 10. ll. 12. 13. LIST OF FIGURES Drawings of leaf-petiole cuttings representing Saintpaulia cultivars 'Star Girl Seedling' and 'Queen‘s Cushion' . . . . Effects of three foliar sprays of certain chemicals on leaf- petiole cuttings of Sainmaulia cultivar 'Star Girl Seedling' . Effect of three foliar sprays of certain chemicals on leaf- petiole cuttings of Saintpaulia cultivar 'Queen's Cushion' .' . Average maximum diameter measurements of Saintpaulia 'Star Girl Seedling' control plants compared to those treated with 100 parts per million maleic hydrazide . . . . . . . . Average maximum diameter measurements of Saintpaulia 'Star Girl Seedling' control plants compared to those treated with 25 parts per million triiodobenzoic acid . . . . . . . . Average maximum diameter measurements of Saintpaulia ‘Star Girl Seedling' control plants compared to those treated with 100 parts per million indoleacetic acid. . . . . . . . . Average maximum diameter measurements of Saintpaulia ‘Star Girl Seedling' control plants compared to those treated with 100 parts per million gibberellic acid. . . . . . . . . Average maximum diameter measurements of Saintpaulia 'Queen's Cushion' control plants compared to those treated with 100 parts per million maleic hydrazide. . . . . . . . Average maximum diameter measurements of Saintpaulia 'Queen's Cushion‘ control plants compared to those treated with 25 parts per million triiodobenzoic acid. . . . . . . Average maximum diameter measurements of Saintpaulia cultivar 'Queen's Cushion' control plants compared to those treated with 100 parts per million indoleacetic acid . . . . Page 14 16 32 33 34 35 36 37 38 FIGURE 14. 15. 16. l7. l8. 19. 20. 21. 22. 23. LIST OF FIGURES Cont'd Average maximum diameter measurements of Saintpaulia cultivar 'Queen's Cushion’ control plants compared to those treated with 100 parts per million gibberellic acid. . . . . . Average maximum diameter measurements of Saintpaulia cultivar 'Queen's Cushion' and cultivar 'Star Girl Seedling' as influenced by several growth regulators. . . . . . . . Photograph of representative plants of Saintpaulia cultivar 'Star Girl Seedling" from treated groups . . . . . . . . . . Photograph of representative plants of Saintpaulia cultivar 'Queen‘s Cushion' from treated groups . . . . . . . . .- . . Style of Saintpaulia cultivar 'Star Girl Seedling‘ from flower ofuntreatedplant. . . . . . . . . . . . . . . Deeply split style from flower of 100 parts per million gibber- ellic acid treated Saintpaulia cultivar ‘Star Girl Seedling' . Saintpaulia cultivar 'Star Girl Seedling' showing effect of gibberellic acid on growth habit. . . . . . . . . . . . . . Saintpaulia cultivar 'Queen‘s Cushion' showing effect of 100 parts per million gibberellic acid on growth habit . . . . . Leaves from Saintpaulia cultivar 'Star Girl Seedling' showing the effect of gibberellic acid . . . ....... . . . . . Leaves from Saintpaulia cultivar 'Queen's Cushion‘ showing the effect of gibberellic acid . ..... . . . . . Page 39 4O 41 42 48 49 51 52 54 55 TABLE OF CONTENTS Page INTRODUCTION ..................... 1 REVIEW OF LITERATURE .............. . . 2 General Effects of Growth Regulators ........ 2 Effect of Plant Growth Regulators on Flowering. . . . 3 Effect of Flower Lasting Quality ....... . . . 4 Effecton Pollen Germination . . . . . . . ..... 6 Effect on Rooting Cuttings ............. 6 MATERIALS AND METHODS . . . .' . . ......... 9 EXPERIMENTAL RESULTS . . . ............ 13 Effect of Growth Regulators on Rooting ...... . 13 Effect on Pollen Germination ............ 27 Effect on Growth . . ........ . . . . . . . 30 Effect on Number of Flowers and Peduncles . . . . . . 30 Effect on Lasting Quality of Flowers . . . . . . . . . 44 Morphological Changes ............... 46 DISCUSSION OF RESULTS ................. 56 Rooting Leaf-Petiole Cuttings ............ 56 Pollen Germination . . . . . . . ........ . . 57 Growth............. .......... 58 TABLE OF CONTENTS Cont'd Page Flower and Peduncle Production . . . ..... . . . . 59 Lasting Quality of Flowers . . . ........... 60 MorphologicalChanges................ 61 SUMMARY ...................... . . . 64 LITERATURE CITED . . . . . . . . . ........... 67 .u .s TABLE II. III. VI. VII. VIII. IX. LIST OF TABLES Effect of Foliar Application of Maleic Hydrazide, Indole- acetic Acid and Gibberellic Acid at 100 Parts per Million on Rooting Leaf-Petiole Cuttings of Saintpaulia, Cultivar 'Star Girl Seedling' . . . . . . ..... . . . . . Effect of Foliar Application of Maleic Hydrazide, Indoleacetic Acid and Gibberellic Acid at 100 Parts Per Million on Root- ing Leaf-Petiole Cuttings of Saintpaulia, Cultivar 'Queen's Cushion'........ ..... . .......... Effect of Foliar Application of Maleic Hydrazide, Indoleacetic Acid and Gibberellic Acid at 100 Parts per Million and Tri- iodobenzoic Acid at 25 Parts per Million on Rooting Leaf-Pet- iole Cuttings of Saintpaulia, Cultivars 'Star Girl Seedling and 'Queen's Cushion'. . . . .............. Chi-square Analysis of Rooting Between Cultivars ..... Chi-square Analysis of Rooting Between Cultivars (Continued) Effect of Certain Growth Regulators on Germination of Pollen of 'Star Girl Seedling' Saintpaulia ........... . Percentage Germination of Pollen Grains from Growth Regu- lator Treated Plants of Cultivar 'Star Girl Seedling‘ . . . . Effect of Certain Growth Regulators on Maximum Diameters of Two Saintpaulia Cultivars . . . . . . ....... . . Effect of Certain Growth Regulators on Number of Flowers and Peduncles of Saintpaulia Cultivars 'Star Girl Seedling' and 'Queen's Cushion' from June 1, 1957 to August 23, 1957. . . Effect of Certain Growth Regulators on the Lasting Quality of Saintpaulia Flowers. . . . . . . ..... . . . . . . Page 17 18 19 20 21 28 29 31 43 45 TO MY PARENTS John Louis and Sophia Roberts AND MY FAMILY Rosa, Katherine, Ronald, Carol and Louis ACKNOWLEDGEMENT The author expresses his sincere appreciation to Doctors Garrick E. Wildon, William D. Baten, John H. Beaman, Charles L. Hamner, Leo W. Mericle, Gurbachan S. Rai, and Donald P. Watson for their guidance and encouragement during the investigation and the preparation of this manuscript. INTRODUCTION Saintpaulia, the African violet, has become an important cultivated plant. Over two and one-half million plants were grown under glass by 992 commercial growers according to Special Reports on Horticultural Specialties of the 1950 United States Census of Agriculture. These plants sold for over one million dollars. They were eighth in rank as compared to potted roses, which ranked ninth in regard to the number of plants produced and sold. Many plants are grown by amateurs. The second largest specialized plant society'in the United States is the African Violet Society of America, Incorporated. Its 15, 000 membership of commercial growers and amateurs represents only a fraction of growers of this plant. Further interest is indicated by scientific literature concerning Saintpaulia found in botanical journals and horticultural periodicals (4, S, 8, 10, 14, 18, 22, 28, 29, 30, 36). Since Saintpaulia is an important horticultural plant, growers are interested in its response to any factors which modify its growth. The purpose of this investigation was to study the effect of certain growth regulators on Saintpaulia. REVIEW OF LITERATUR E Innumerable articles concerning plant growth regulators have been reported. Only a few (3, 13, 21, 33, 39) are concerned with the effects of growth regulator application to Saintpaulia. General Effects of Growth Regulators The principle modifications induced by plant growth regulators ac- cording to Zimmerman (43) are, "changes in flowering habit, size, shape, pattern, and venation of organs". Zimmerman and Hitchcock (45) reported pattern of leaves, flowering habit, and correlation of organs of the plants were modified by application of 2, 3, 5 triiodobenzoic acid (TIBA) to soil in which potted tomato plants were growing. Beta-naphthoxyaliphatic acids, substituted phenoxyaliphatic acids, and substituted benzoic acids have formative effects on plants (43). "Forma- tive effects may be defined as changes in pattern from that normally result- ing from the genetic constitution of the plant under the influence of particular environments. When the environment is more or less constant for a usual habitat, the size and shape of the plant and pattern of organs are said to be constant for a usual habitat, the size and shape of the plant and pattern of organs are said to be normal for a given species. Unusual environments involving temperature, moisture, light or chemical substances bringing about different expressions of so-called normal characteristics. The re- sults may be referred to as formative effects brought about by a given com- bination of influences" (43). Effect of Plant Growth Regulators on Flowering Attempts have been made to control flowering by the application of growth regulators. Galston (12) tried to initiate flowering in 'Peking' and 'Biloxi‘ soybeans by soil application, foliar application and intracotyledonary injection of a saturated solution of triiodobenzoic acid. Since flowering was not induced he concluded triiodobenzoic acid did not have "florigenic" pro- perties. Morphological responses, such as shortening of the internodes, loss of apical dominance, and epinasty of young leaves were induced. The pineapple appears to have been the only plant in commercial production in which flowering has been initiated by external application of growth regulators. Van Overbeek (38) poured 50 milliters of a solution con— taining . 25 to . 5 milligram of alpha-naphthaleneacetic acid into the center of the plants to induce flower development in the primordia. This method of flower control is now being used extensively by pineapple growers in South America and Hawaii (2). Although growth regulators induced flower initiation only in the pineapple, they have been found to modify flower initiation in a large number of plants. In certain plants, Circaea, Kalanchoe, Impatiens balsamina, and Calendula officinalis, auxin has been reported to have inhibited flower initia- tion (2). Flower initiation in celery and lettuce has been prevented by foliar application with a solution of 100 parts per million alpha-Z-chlorophenoxy- propionic acid (42). Spraying maleic hydrazide on foliage of maize plants with . 025 solution caused male flower tassels to be completely sterile but did not affect female flowers (27). Hitchcock and Zimmerman (17) reported that flowering of Turkish tobacco was hastened by soil application of indolebutyric acid in 3 and 9 milli- gram doses. At the end of 3 weeks, flower buds were visible on 16 of 36 plants and one of the 12 control plants. Certain dilute foliar sprays of growth regu- lators have been reported to have no effect on flowering of a range of crop plants, such as winter oats, wheat, string beans, peas, carrots and clover (2). Effect on Flower Lasting Quality There are few reports on the use of growth regulators for prolong- ing blooming of ornamental plants. Wester and Marth (2) sprayed the leaves of oriental cherries (Prunus serrulata) with alpha-naphthaleneacetic acid and reported that 25 to 80 percent of the blossoms were retained for 3 to 10 days longer. Dogwood (Cornus florida) had blossoms retained 4 to 6 days longer than untreated plants after the foliar application of 4-chlorphenoxyacetic acid. Other species including Azalea, flowering almond, lilac and magnolia were unresponsive. Lindstrom and Wittwer (24) investigated the effect of foliar appli- cation of 10 parts per million gibberellin on the foliage of 'Spartan White' geranium (Pelargpnium hortorum) plants when a few florets of the inflores- cence were beginning to open and show flower color. They reported that the life of the inflorescence was lengthened as a result of treatment from one to two weeks longer. Inflorescences of another cultivar, 'Brick Red Irene' geranium treated with gibberellin at 10 parts per million were un- affected, thus indicating that different cultivars of a species may respond differently to the same concentration of a growth regulator. Flowers of Fuchsia hybrida exposed to vapors of napthaleneacetic acid for 10 minutes lasted 5 to 10 days longer than controls while flowers of tomato exposed to vapors of esters of various chlorophenoxy compounds lasted 10 to 30 days longer than the untreated plants (44). Kelly (20) reported experiments with foliar application of 1000, 2000, and 4000 parts per million maleic hydrazide to the snapdragon (A_n_t_i_£_r_- hinum majus) cultivar 'Snowman'. He applied the various concentrations one and three days before harvest and found no effect on lasting quality of the cut flowers. Effect on Pollen Germination Effect of growth regulators on pollen germination and growth has’ been the subject of experimentation by various investigators (l, 6, 15, 25, 31, 34). Addicott (1) tested 33 pure growth substances for their effect on pollen germination and tube growth. He used Tropaeolum and Milla and found that 16 growth substances significantly increased germination as well as tube growth. He also established that germination‘of pollen and tube growth are at least in part physiologically independent from each other. Brock (6) reported interspecific hybrids between pear and apple by using hormones. He applied B-naphthoxyacetic acid to the base of the pear style at the time apple pollen was placed on the stigma. This stimulated apple pollen-tube growth, and allowed fertilization. Viable seed- lings developed from these crosses and 37 percent were still alive after four months of growth. The seedlings seemed to be intermediate in phenotypic expression between apple and pear. Effect on Rooting Application of auxins by spraying leaves is discussed by Audus (2) who states that some success was obtained by spraying leaves of certain evergreen species with dilute aqueous solutions of auxins before removal of the cuttings from the parent plants. Hildreth and Mitchell (16) found sprays containing 300 milligrams per liter of indolebutyric acid were effective for rooting cuttings of bean, marigold, coleus, marguerite and carnation, but cuttings were sprayed after they had been inserted into the rooting medium. Kiplinger (21) has discussed propagation of Saintpaulia by means of leaf-petiole cuttings and states that treatment with growth substances will hasten rooting, but has no beneficial effect on formation of new shoots. Jones (19) mentions the use of hormone powders to assist rooting as neither necessary nor beneficial, since the rooting of leaf-petiole cuttings is usually very good, in fact almost 100 percent successful provided that the temper- ature is at least 60’F and humidity is maintained. Neither Kiplinger nor Jones present experimental evidence or support of their statements with citations. Warner and Went (39) reported that more roots were produced per cutting by soaking leaf -petiole cuttings in a solution of 50 parts per million indoleacetic acid for 16 hours than in control cuttings, although 100 percent rooted in each group. Smith (33) working with Saintpaulia cultivar 'Purple Beauty' stood leaf-petiole cuttings one-half inch into a solution of 40 parts per million indolebutyric acid for 24 hours. He found greatly stimulated root-formation on treated cuttings as compared to untreated cuttings, but succeeding shoot growth was inhibited by treatment with 40 parts per million indolebutyric acid. From the experiments of Smith (33) and those cited by Avery (3) it may be concluded that certain growth regulators are beneficial for pro— ducing roots on certain cultivars of Saintpaulia, and that certain growth regulators accelerate root production. In these experiments the stems of leaves were either soaked in solutions containing plant growth regulators or were dusted with powders containing them. Gray (13) applied 16 parts per million gibberellic acid to Saint- paulia plants and found leaf blades grew longer and narrower forming an apex much more acute than those of the control plants. The petioles grew longer and more erect, and the flowers seemed larger and more abundant. MATERIALS AND METHODS To determine the effect of foliar application of various growth regu- lator solutions on Saintpaulia two cultivars were selected, 'Star Girl Seedling' and 'Queen's Cushion', which appear to have been derived from Saintpaulia ionantha. Both cultivars were obtained from a commercial grower", who had propagated them by means of leaf-petiole cuttings. The cultivar 'Star Girl Seedling' was propagated on August 16, 1956, while 'Queen's Cushion' was propagated on May 14, 1956. The plants were delivered to the Plant Science greenhouse, Michigan State University on November 27, 1956 and were immediately divided, sel- ected for uniformity and vigor, and repotted. A single crown plant was potted in each 6-inch standard clay flower pot. The plants were grown on benches in the greenhouse (night temper- ature 65° F). They were arranged in 6 rows of 40 plants on each of two benches, a total of 240 plants of each of two cultivars. They were then labeled accord- ing to the randomized design of the experiment. For each variety there were five treatments including the control. Groups of four plants per treatment were randomized in each 40-plant row. There were six replications of each treatment. The outside row of one bench served as a guard row because it *Westside Greenhouses, Inkster, Michigan. 10. was near heating coils located on a side wall. The outside row of the other bench also served as a guard row. Three plants from each treated group of one bench including the controls were labeled for obtaining data concerning the number of flowers and maximum diameter measurements. As the guard row was not included in these data, these records were based on three plants per treatment; five treatments per cultivar with five replications. Thus, there were seventy-five plants of each of two cultivars included in obtaining data for the number of flowers and the greatest diameter measurements. In the second bench, three plants from each group, including the controls were labeled for obtaining data on lasting quality of flowers and the number of peduncles. The guard row was not included in data from the second bench, and the records were based on three plants per treatment; five treatments per cultivar with five replications. Thus, there were seventy-five plants of each of two cultivars included in obtaining data for the lasting quality of the flowers. One plant in each treated group including the replications from both benches was labeled for obtaining leaves for an investigation of the rooting of leaf-petiole cuttings. After the plants were allowed to grow for five months the treat- ments consisting of: control, 100 parts per million indoleacetic acid, 100 11. parts per million gibberellic acid, 25 parts per million triiodobenzoic acid were applied on May 1, 1957. The chemicals were dissolved in l milliliter of ethyl alcohol and made up to the proper volume with distilled water. New solutions were prepared for each application. Plant groups were moved into an adjoining house where the various growth substances were applied by means of a hand sprayer. Each group was shielded so as to prevent the spray from drifting to other plants. The sprayer was carefully cleaned by rinsing in tap water ten times, once in ethyl alcohol and twice with distilled water after each spray material was used. The plants were then placed in their original positions on the benches. On May 22 a second spray application of growth regulators was applied. On June 12 the third and final application was made. To determine the effects of various growth regulators on rooting response, fifty uniform leaf-petiole cuttings were obtained from treated plants eight days after the last treatment date. They were inserted in sand contained in trays, which, in turn, were kept in a water bath having a con- stant temperature of 75' F. Thirty-four days from insertion date, cuttings were removed from sand medium for evaluation of root development. Data obtained were sub- jectively divided into four groups: (1) not rooted, (2) lightly rooted, (3) inter- mediately rooted, and (4) heavily rooted cuttings, based on visual obser- 12. vations. The data were analyzed statistically and results presented in "Experimental Results". Starting June lst data were recorded on the number of flowers on each inflorescence and the number of peduncles. Data were also obtained concerning the lasting quality of each flower. Lasting quality was deter- mined by recording the number of days between time of complete opening and time first wilting of petals was visible. On June 29th, pollen was selected from flowers of cultivar 'Star Girl Seedling' in the various groups to determine if its germination had ' been adversely affected. Anthers from two flowers per plant per treated group, including control, were selected from both benches. Thus, there were anthers from 20 flowers from each treatment. Pollen from the anthers within a group was mixed together for uniformity of sampling. This was done for all groups. A sample was selected from each group mixture and placed on hanging drops of a 15 percent sucrose solution made with distilled water. Pollen was germinated at room temperature. Germination data were recorded and the results analyzed statistically. Maximum diameters of the plants were measured every two weeks from May 2 to June 12 to ascertain total growth as represented by the in- crease in size of maximum diameter of plants every two weeks. Graphs were made from recorded data. In addition to these measurements and recorded data, observations were made regarding changes in shape or form of plant parts. 13. EXPERIMENTAL RESULTS Effect of Growth Regulators on Rooting The rooted cuttings were subjectively divided into the following four groups: (1) not rooted, (2) lightly rooted, (3) intermediately rooted, and (4) heavily rooted, based on visual observation. Drawings of a representative cutting of each class are shown in Figures 1 to 4. The resulting data presented in Tables I and II show the effect of foliar application of maleic hydrazide, indoleacetic acid and gibberellic acid at 100 parts per million, and triiodobenzoic acid at 25 parts per million on rooting response of leaf ~petiole cuttings of two cultivars of Saintpaulia, ‘Star Girl Seedling' and 'Queen's Cushion'. Data in Tables I and II are the result of separating and counting the cuttings into the various classes. These numbers are expressed in percentages in Table. III and are graphically shown by bar diagrams in Figures 5 and 6. Chi-square analysis as shown in Tables IV and V indicate totals of all classes of leaf-petiole cutting rooting responses of Saintpaulia cultivar ‘Star Girl Seedling' to the various treatments were different than the totals of all classes of leaf-petiole cutting rooting responses of cultivar 'Queen's Cushion'. However, a comparison between the control groups of cultivar ‘Star Girl Seedling' and the control groups of cultivar 'Queen's Cushion' indicates l I " , - 1‘ Figure l i r . l f . l . 1‘ 4 -1 l , . ‘ l . l J l t l Figure '3' ' an... ‘ Figures 1 to‘4. Drawings of leaf-petiole cuttihgs representing Saint aulla , ‘ cultivars 'Star Girl Seedling' and Queen's Cushion'. Drawings ' illustrate the approximate stage of rooting by Which cuttings were classified into groups. Figure 1, fnot rooted. Figure 2, lightly rooted. Figure 3, intermediately‘rooted. Figure 4, heavily ‘ rooted; :7 III. 4 I Iv ~ x i , ‘ ‘ ‘ ' ~ t ' v , t ‘ I _ _. .,. ._ .._,_._l._. .. . 41. ..e L_._., .._.,.,.,.,.. 15, - Ah .- - Ln.... .5“. _.+_—_—.———.n‘_‘n_fi--_...._ .28 0:29.330 can 2: Amy .28 058285 can 2: A8 .22... Eon; Eng mm 68 GENE?» 2322 can o3 Amy 40.2.80 35 ..m5 mom E5 .35. 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Number of Cuttings in Each Class Treatment Not Lightly Intermediately ~ Heavily Total Cuttings Rooted Rooted Rooted Rooted per Treatment Control 1 7 23 19 50 Maleic Hydrazide 0 5 29 16 50 Triiodobenzoic Acid 6 7 31 6 50 Indoleacetic Acid 0 6 36 8 50 Gibberellic Acid 0 21 27 . 2 50 Total Cuttings in Each Class 7 46 146 51 250 —— TABLE II Effect of Foliar Application of Maleic Hydrazide, Indoleacetic Acid and Gibber- e11 1' c Acid at 100 parts per million, and Triiodobenzoic Acid at 25 parts per 111 1' 1 1 i on on Rooting Leaf-Petiole Cuttings of Saintpaulia Cultivar 'Queen‘s Cushion'. ~ I Number of Cuttings in Each Class T1. 6 a tment Not Lightly Intermediately Heavily Total Cuttings Rooted Rooted Rooted Rooted per Treatment Co 11 t: r01 1 12 22 15 50 Maleic: *1 y d razide 4 22 15 9 50 Tri i o dobenzoic Ac: :1 <1 0 29 17 4 50 ““10 1 eacetic ’5‘?— i <1 5 22 19 4 so Gibberellic Re i d 11 35 4 0 50 T?ta 1 Cuttings 1n Each Class 21 120 77 32 250 k 19. TABLE 111 Effect of Foliar Application of Maleic Hydrazide, Indoleacetic Acid, and Gib- bere llic Acid at 100 parts per million, and Triiodobenzoic Acid at 25 parts per million on Rooting Leaf-Petiole Cuttings of Saintpaulia Cultivar ‘Star Girl See d1 ing' (S. G. S.), and ‘Queen's Cushion' (Q. C. ). ~ Classes of Cuttings Trea tment Percent Percent Lightly Percent Inter- Percent Not Rooted Rooted mediately Heavily Rooted Rooted s.o.s. Q.C. s.c.s. Q.C. 3.0.5. Q.C. S.G.S. Q.c. x Cont r01 2 2 14 24 46 44 38 30 M31 e i C Hy dxazide O 8 10 44 58 30 32 18 Tri. i— Q dobenzoic AC 1 <3 12 0 14 58 62 34 12 8 “:01 eacetic Q i d 0 10 12 44 72 38 16 8 G“D‘Detellic ‘ Ci (1 O 22 42 70 54 8 4 0 20. TABLE IV Chi-Square Analysis of Rooting Between Cultivars Cultivar Cultivar and F“) X2 (2) P:.05(3) Signifi- and F“) x20) p=,05(3) Signifi— .. ll! . Treatment cant “ Treatment cant: " V100 vs. V201 l 14. 8 3. 84 * V100 vs. V200 2 l. 7 5. 99 V100 vs. V202 l 18. 2 3. 84 ”' V100 vs. V203 2 16. 2 5. 99 "" V100 vs. V204 l 58. 2 3. 84 * V101 vs. V200 2 3. 7 5. 99 V101 vs. V201 2 l8. 8 5. 99 ”‘ V101 vs. V202 2 27. 4 5. 99 "' V101 vs. V13 2 24. 4 5. 99 * V101 vs. V204 2 73.2 5. 99 "‘ V102 vs. V200 2 5. 2 5. 99 V102 vs. V203 2 14. 0 5. 99 * V102 vs. V201 2 16. 2 5. 99 ”‘ V102 vs. V203 2 8. 2 5. 99 * V102 vs. V204 2 50. 8 5. 99 * V103 vs. V200 2 5. l 5. 99 V103vs. V203 2 19. 0 5. 99 ’7‘ V103 vs. V201 l 18. 4 3. 84 * V103 vs. V202 1 30. 4 3. 84 ’°' V103 vs. V204 2 184. 4 5. 99 "' V104 vs. V200 2 12. 9 5. 99 "‘ V104 vs. V204 2 33. 6 5. 99 * V104 vs. V201 l 10. 2 3. 84 * V104 vs. V202 1 2. 6 3. 84 V104 vs. V203 l 1. 5 3. 84 k (1) F 1 Degrees of freedom (2) X2 = Chi-square (3) P 2 Probability Key To Table 00 = Control 01 x 100 parts per million maleic hydrazide 02 a 25 parts per million triiodobenzoic acid 03 = 100 parts per million indoleacetic acid 04 x 100 parts per million gibberellic acid V1 8 'Star Girl Seedling' V2 2 . 'Queen's Cushion' TABLE V Chi-Square Analysis of Rooting Within Cultivars Cultivar Cultivar and F“) x742) P: . 05(3) Signifi- and F“) x742) p... 05(3) Signifi- Treatment cant I * Treatment cant .-. * V100 vs. V101 2 l. 7 5. 99 V200 vs. V201 2 7. 7 5. 99 * V100 vs. V102 2 9. 2 5. 99 "‘ V200 vs. V202 2 13. 0 5. 99 * V100 vs. V103 2 7. 5 5. 99 * V200 vs. V203 1 79. 9 3. 84 * V100 vs. V104 l 8. 2 3. 84 * V200 vs. V204 l 44. l 3. 84 * V101 vs. V100 2 l. 7 5. 99 * V201 vs. V200 2 7. 7 5. 99 * VlCl vs. V102 2 8. 3 5. 99 ” V201 vs. V202 2 2. 2 5. 99 V101 vs. V103 2 4.1 5. 99 V201 vs. V203 2 2. 5 5. 99 V101 vs. V104 2 20. 9 5. 99 ”‘ V201 vs. V204 2 19. 0 5. 99 ’°‘ V102 Vs. V100 2 9. 2 5. 99 * V202 vs. V200 2 l3. 0 5. 99 * V102 vs. V101 2 8. 3 5. 99 * V202 vs. V201 2 2. 2 5. 99 V102 vs. V103 2 3. 2 5. 99 “' V202 vs. V203 2 . 2 5. 99 V102 vs. V104 2 4. 0 5. 99 * V202 vs. V204 2 18. 0 5. 99 V103 vs. V100 2 7. 5 5. 99 ”' V203 vs. V200 l 79. 9 3. 84 V103 vs. V101 2 4. l 5. 99 * V203 vs. V201 2 2. 5 5. 99 V103 vs. V102 2 3. 2 5. 99 * V203 vs. V202 2 . 2 5. 99 V103 vs. V104 2 10. 9 5. 99 * V203 vs. V204 2 l7. 0 5. 99 "' V104 vs. V100 l 8. 2 3. 84 * V204 vs. V200 1 44. l 3. 84 * V104 vs. V101 2 20. 9 5. 99 * V204 vs. V201 2 l9. 0 5. 99 * V104 vs. V102 2 4. 0 5. 99 "' V204 vs. V202 2 l8. 0 5. 99 * V104 vs. V103 2 10. 9 5. 99 ’“ V204 vs. V203 2 l7. 0 5. 99 * V1 vs. V2 3 65. 3 7. 81 "‘ (1) F = Degrees of freedom (2) x2 a Chi-square ‘ (3) P 8 Probability Key To Table 00 2 Control 01 z 100 parts per million maleic hydrazide 02 = 25 parts per million triiodobenzoic acid 03 x 100 parts per million indoleacetic acid 04 = 100 parts per million gibberellic acid VI = 'Star Girl Seedling' V2: 'Queen's Cushion' 22. no significant difference. This indicates similarity in rooting response of untreated leaf-petiole cuttings of cultivar 'Star Girl Seedling‘ and 'Queen‘s Cushion' as grown under the same environmental conditions. Leaf-petiole cuttings of cultivar 'Star Girl Seedling' responded differ- ently to the chemical treatments than cultivar 'Queen's Cushion'. One hundred parts per million maleic hydrazide, indoleacetic acid and gibberellic acid and 25 parts per million triiodobenzoic acid produced significantly different re- sponses in the rooting of leaf-petiole cuttings of 'Star Girl Seedling' as com- pared to 'Queen’s Cushion', indicating a difference in response to chemical treatments between different cultivars of Saintpaulia. However, certain treatments when analyzed by chi-square, indicated no significance in rooting response. They are as follows: (1) 100 parts per million maleic hydrazide treated cuttings of 'Star Girl Seedling' as compared to untreated cuttings of 'Queen's Cushion'; (2) the 25 parts per million tri- iodobenzoic acid treated cuttings of 'Star Girl Seedling' compared to untreated cuttings of 'Queen's Cushion'; (3) the 100 parts per million indoleacetic acid treated cuttings of 'Star Girl Seedling' compared to untreated cuttings of 'Queen's Cushion'; and (4) 100 parts per million gibberellic acid treated cuttings of 'Star Girl Seedling' as compared to 100 parts per million indole- acetic acid treated cuttings of 'Queen's Cushion'. In all other two-way com- parisons between cultivars, chi-square analysis indicated significant differ- ences in rooting response to treatments (Table IV). 23. Chi-square analysis was also used to compare the various treatments within each cultivar for significant differences (Table V). Following are the results of comparing treatments within cultivar 'Star Girl Seedling': 1. Comparisons Resulting in Significant Differences: (1) Control compared to 25 parts per million triiodobenzoic acid. (2) Control compared to 100 parts per million indoleacetic acid. (3) Control compared to 100 parts per million gibberellic acid. (4) 100 parts per million maleic hydrazide compared to 25 parts per million triiodobenzoic acid. (5) 100 parts per million maleic hydrazide compared to 100 parts per million gibberellic acid. (6) 25 parts per million triiodobenzoic acid compared to control. (7) 25 parts per million triiodobenzoic acid compared to 100 parts per million maleic hydrazide. (8) 100 parts per million indoleacetic acid compared to control. (9) 100 parts per million indoleacetic acid compared to 100 parts per million gibberellic acid. 24. (10) 100 parts per million gibberellic acid compared to control. (11) 100 parts per million gibberellic acid compared to 100 parts per million maleic hydrazide. (12) 100 parts per million gibberellic acid compared to 100 parts per million indoleacetic acid. 11. Comparisons Resulting in Non~Significancez (1) Control compared to 100 parts per million maleic hydrazide. (2) 100 parts per million maleic hydrazide compared to control. (3) 100 parts per million maleic hydrazide compared to 100 parts per million indoleacetic acid. (4) 25 parts per million triiodobenzoic acid compared to 100 parts per million indoleacetic acid. (5) 25 parts per million triiodobenzoic acid compared to 100 parts per million gibberellic acid. (6) 100 parts per million indoleacetic acid compared to 100 parts per million maleic hydrazide. (7) 100 parts per million indoleacetic acid compared to 25 parts per million triiodobenzoic acid. 25. (8) 100 parts per million gibberellic acid compared to 25 parts per million triiodobenzoic acid. The following are the results of comparing treatments within the culti- var 'Queen's Cushion': 1. Comparisons Resulting in Significant Differences: (1) Control compared to 100 parts per million maleic hydrazide. (2) Control compared to 25 parts per million triiodobenzoic acid. (3) Control compared to 100 parts per million indoleacetic acid. (4) Control compared to 100 parts per million gibberellic acid. (5) 100 parts per million maleic hydrazide compared to control. (6) 100 parts per million maleic hydrazide compared to 100 parts per million gibberellic acid. (7) 25 parts per million triiodobenzoic acid compared to control. (8) 25 parts per million triiodobenzoic acid compared to 100 parts per million gibberellic acid. 26. (9) 100 parts per million indoleacetic acid compared to control. (10) 100 parts per million indoleacetic acid compared to 100 parts per million gibberellic acid. (1 1) 100 parts per million gibberellic acid compared to control. (12) 100 parts per million gibberellic acid compared to 100 parts per million maleic hydrazide. (13) 100 parts per million gibberellic acid compared to 25 parts per million triiodobenzoic acid. II. Comparisons Resulting in Non-significant Differences: (l) 100 parts per million maleic hydrazide compared to 25 parts per million triiodobenzoic acid. (2) 100 parts per million maleic hydrazide compared to 100 parts per million indoleacetic acid. (3) 25 parts per million triiodobenzoic acid compared to 100 parts per million maleic hydrazide. (4) 25 parts per million triiodobenzoic acid compared to 100 parts per million indoleacetic acid. (5) 100 parts per million indoleacetic acid compared to 100 parts per million maleic hydrazide. 27. (6) 100 parts per million indoleacetic acid compared to 25 parts per million triiodobenzoic acid. (7) 100 parts per million gibberellic acid compared to 100 parts per million indoleacetic acid. Effect on Pollen Germination Pollen grains of only one cultivar, 'Star Girl Seedling' were used, since it was a single flowering cultivar and produced pollen. Cultivar, 'Queen‘s Cushion' was not used, since it was a double flowering cultivar and produced very little pollen. One hundred pollen grains were counted in each sample (Table VI). Since the germination percentages were small, they were converted to angles by a table given by Snedecor (35). A statistical analysis was carried out on the data in Table VII. The calculated F value indicated that one or more differences among the means were significant. Significance between the means was determined by the use of a Studentized Range Tables by Duncan (9). The significances of the means were found to be: Control ‘ significantly greater than TIBA, 1AA, MA, GA. TIBA significantly greater than MH, GA, 1AA 1AA significantly greater than MH, GA GA significantly greater than MH 28. TABLE VI Effect of Certain Growth Regulators on Germination of Pollen of 'Star Girl Seedling' Saintpaulia. ._-7 -_ J—W‘f J“ L Number Germinating Pollen Grains in lOO-Grain Samples T ° 1 “3 Mlifl) TIBA(2) LAA(3) GA“) CONTROL 100 ppm 25 ppm 100 ppm 100 ppm 1 5 5 8 2 6 2 3 5 5 9 13 3 4 10 6 2 l4 4 3 4 4 5 ll 5 4 9 3 4 9 Totals 19 33 26 22 53 Averages 3. 8 6. 6 5. 2 4. 4 10. 6 (1) = maleic hydrazide (2) = triiodobenzoic acid (3) = indoleacetic acid (4) z gibberellic acid 29. TABLE VII Percentage Germination of Pollen Grains from Growth Regulator Treated Plants of Saintpaulia Cultivar 'Star Girl Seedling. (Data from TABLE VI Converted to Angles) Number Germinating Pollen Grains in lOO-Grain Samples (Numbers Converted to Ages) Trial Mil“) T113412) . 1AA<3) GA“) CONTROL 100 ppm 25 ppm 100 ppm 100 ppm 1 13 _ 13 16 8 l4 2 10 l3 13 17 21 3 12 18 14 8 22 4 10 12 12 13 19 5 12 17 10 12 17 Averages 11.4 14.6 13. 0 11.6 18.6 (1) x maleic hydrazide (2) x triiodobenzoic acid indoleacetic acid (3) N (4) gibberellic acid 30. Effect on Growth To determine the growth of experimental plants, their maximum rosette diameters were measured every two weeks by means Of an 18-inch wood caliper, and the data were recorded. Measurements of each group for each two-week period were averaged. This was repeated for all replicates. These averages were, in turn, averaged, in order to get the averages of replication averages per treatment. This was done for all treatment groups including control (Table VIII). Graphs were made to show growth rates (Figures 7 to 15). Figures 16 and 17 show representative plants from each treated group as they appeared on July 5, 1957. Effect on Number Of Flowers and Peduncles To determine the number Of flowers and peduncles, flowers and peduncles were harvested, counted, recorded and discarded at two-week intervals from June 1, 1957 to August 23, 1957. The average number of flowers for each treatment and the average number of peduncles for each treatment are shown in Table IX. An analysis Of variance was made for each set Of data, that is, for average number of flowers per treatment. The results of both analyses showed that the treatments were highly signi- ficant to the 1 percent level. Significance among the means was determined according to Duncan's method (9). TABLE VIII Effect of Certain Growth Regulators on Maximum Diameters of Two Saintpaulia Cultivars Average Maximum Diameters 15 Plants (Inches) Treatment Measurement Dates May 2 May 16 May 30 June 13 June 27 July 11 Cultivar 'Star Girl Seedling‘ MH, 100 ppm 6. 0 6. 2 6. 4 6. 6 6. 9 7. 1 TIBA, 25 ppm 6. 4 6. 4 6. 7 6. 8 7. 0 7. 1 1AA, 100 ppm 5. 9 6. 1 6. 3 6. 3 6. 6 6. 8 GA, 100 ppm 6. l 6. 5 8. 5 8. 5 9. 7 10. 9 Control 6. 2 6. 4 6. 7 6. 9 7. l 7. 3 Cultivar 'Queen's Cushion' MH, 100 ppm 8.2 8. 5 9.3 9.7 10. 1 10.2 TIBA. 25 ppm 9. 1 9. 2 9. 3 9. 6 10. 0 10. 3 1AA, 100 ppm 9.3 9.5 9.7 10.0 10.4 10.7 GA, 100 ppm 9.6 10.3 11.2 11.3 12.7 13.0 Control 9. 1 9. 1 9. 4 10. 0 10. 9 11. 4 MH 1’ maleic hydrazide TIBA == triiodobenzoic acid 1AA = indoleacetic acid GA 2 gibberellic acid. (so. "'T‘ ’ ," ' “ TTWIT "7' T T. T' T I F l" l" 3 I" f .12 l . , g E . . , ; . . . . , , , . j . - i i : 4 - - t v I , . _ . 1 ,'. . z. t -_.,. . l ...... i ‘ , l - f f i g , I g i _ I‘. 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A _ :I-. nrl I'II "rf'lt. ’I,lrl'.li"‘.lll'|l.|‘l 'I'lllll'ilnlb 'l’ L LL L P E‘s ..Pllr -.l'IIIII‘I Io‘ - - -III'II‘A III 1r. :51 9?. II .....I .IIII'I‘ Pl it"llrnlrl'".l.l 36. ,——- - A» '_ 77! ... 77 _ 1 ' 7 7 T ' 7‘ V V A 7"! , I ‘ . ‘ . y .9 . A A A ,t A , . 1 1 ‘ , , A g ‘ ‘ - v 3 3 y ' I l’ 1| A . ‘ . . A ‘ [y .14 l , L 1 7 V r v ’ . I , A 7 A V . . , A, , A , A 1 ‘1 1 f r v § q ‘ |. . I A A A I { J :_;_r. .34“ , ' I _ A .1. , . i ’ . 1 A ~ 1 A A 1 > I A A ' ‘ Y a I ' 1 g A V ' r I t ' I T’ .. . VI . ,. A . . , . V . , A . , AA . . ,7 . ?, ..... ; 13 A A . ' . 1, A A ,. A } . . . . 1 .2 1 A A J ',_....- - A A A < —. _ 7 > - § - ..... l A , . ‘A i. : 1 A I "V V V ‘A ‘ r v 0. ' ,< .,A . .7 , . A . V . . A .A , l. .12 A . I l A A i . A A . , AA A A }A . A . ‘ ; ' . A L-—- v I AgrérégerMaxtmfim Dialmieiénl in Indies O on . 1: ‘2‘; 1'3! " .A If"" 'l‘.‘"" ffl’f‘wo-wcekf’ertods’W"‘;"“'f " ; Figure 11. V Theme-:an of gyeragg maximum diametgms 9f Shintpaulia cfilfiivar : 7‘ g ; ' 'Queenfs Cushion' cqntrol plants (V2000) ‘co‘m‘p‘ared to the mafia of f V - . 3 : average maximum diameters of 100 parts per million-maleic; hydra? ; 1 71 ~ zide tréated plants (VzCl 100) ofmgqiingw cultifiar‘Qu'een's i Q . . I i : Cushioh'. Each dotlrepresents aVeragdmaximum diameters of _ i ‘ ' three plants per‘treatment replicated Iiv'c times. a total joi'lfifteen; ‘plantsperdor. , g A V . . . v A b I . A . - . + A . V . A . . . . . : ‘ ; { 5 i I AAAAAAAA A -.,__,_4, .-. .77 Aifi AA _ ._‘,.,.;_L 77777 ,irV.AAA , -.4.,,,‘A,,,4 ¥A.A_¥,A-A .-+.1A.i,;. . ALA 2 Ewe. page? 3mg. M .-IT.,..:A.. ..A~,AH...,A . 4. «. AAA] AI AAIAAA1AIOII All All \AIV All. V l. J‘) A V IA4|A . .0 E A ..Mv . .............. . ,0 w . . .A . . V .. ,. l a . _ w . A .. v-3” . .w 41-322 ..AAH A- AA--- ~ A A. ”f , . u A , . . U m _ m ALI. . A .. . Au.“ 7 U , . . . _ . . . W M . g .../1 A . .AA.v.aA 13.3 A , AAA. ..... 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ArlrlAIAlA [A0 'Avlr’. ll. A: I 14 {II££LA- rfiiui‘on Lindolezicetic. ' Meters of 1002 Sfi'nmaulia Cufitivar , acidt'reated plants '(V ' CushioAi'. pért's .per ' averagé maximum d A 'eter bf three weragc maximUm diiam .‘Queen'p 2c3100) of Each dot represents. a O D -..IFA fifteen plants f 1 .AA.. } tdtal of Y0 times. a H... .A, d” e t a CA .1 m... r LtAAA 1,- A n. 8.. m. O.‘ at - r t Ar. 6,. «RCA AAAA mm r » mAeA AD._D.A H . ., A . . . . ‘ 39 A All. AAA 1|. hr ‘AOIA .al A YAID, A . A . A; . H . 4'. A v m A _ . n . " $.54 r o .AAIA . A _ — w A ...... O 4' j mcérérls. bf .sain' ériOds‘ g' " ..3 1:1? ..TWOTVYééKP O ' Y ! A A; A H A w H. T - 1-14-- L. ..m: A 3. A A A 34-00- H r H A . A A. A . .C AC, u . AAAAAAA AAAAAA -AAAA.A.AA-A - A r. A AAAAA 1A AAA! .AAIAIIAAAA A-A.At A1-.. 2...-.1 Dr. A... A m A A . . .. HA .... A _ A. ..... V A .v. . A . A ...... 4 4AA ... 3 N .A.2 m. . .1. A. . . . 0 a 9. H ..8 ¢.. .1. A . .I... ._ . . A .1 . .. A . 11 . A. . . 1. .A ..A .. A. T... A AL“ I A AA..v... .. AL A AA.A.1A A. A. .A A.AA. A. .. A. A. A W: .. . . .. H . Ammaua,fiwumumaafi Cayuga: mmwuowé. w . A H . A ............ A. , . A . ........ A .AA.A......Q.A .. .A A .A A A {AAIVILIAA K‘AIAr'...AIA AIAAltl'l | LIE LII... .51. AAF‘AAIYA. KAfAAI..A LII: .l .rIAIA. .rLAI IAAA. ADI! ill. .AIAAIAAA I||11A|.YAAAAr. ..AIrAIlA AA A aurh'. ‘ . z . .cillrtly méfiiia 00) compared to thcimean of ; g6. friaxirhum. d1? ‘ of. a‘cera e mejan 1518?“; .lé-A : Th ALA - +AAA A. tivar t arts per million gibberellic 'Queen'§ Cfishjon‘ lcohtrol piants (V20 average; maximum dipmeters of 100 p acid treated plants (V 'Queen's - [204100) of Saintpaulia-cm _ ach dot represents‘avv‘erage maximflm diameter- of three I 1 plants per treatmerim'eplicated five times, a. total of fifteen plants EA Cushion' . i J 1 t I I . t.. A 0 d A I . ..e A .A p o q _ A Average Maximum Diameter in Inches 12 ll 10 0 40. O o \ 000...... \\“ vzclioo vlczzs 1 — VICYIUO o“ V1C3100 r— l 2 3 4 S 6 Two - week periods Figure 15. The mean of average maximum diameters of Saintpaulia cultivars 'Star Girl Seedling' and 'Queen's Cushion'. Vl = 'StarGirl Seedling‘ V2 = 'Queen's Cushion' COO = Control C1100 = 100 parts per million maleic hydrazide C225 = 25 parts per million triiodobenzoic acid C3100 = 100 parts per million indoleacetic acid C4100 = 100 parts per million gibberellic acid 41. Figure 16. Saintpaulia cultivar 'Star Girl Seedling'. From left to right: control; treated with three spray applications of 100 parts per million maleic hydrazide; three spray applica- tions of 25 parts per million triiodobenzoic acid; three applications of 100 parts per million indoleacetic acid; three applications of 100 parts per million gibberellic acid. Photograph taken July 5. 1957. Figure 17. Saintpaulia cultivar 'Queen‘s Cushion. From left to right: control; treated with three spray applications of 100 parts per million maleic hydrazide; three spray applica- tions of 25 parts per million triiodobenzoic acid; three applications of 100 parts per million of indoleacetic acid; three applications of 100 parts per million of gibberellic acid. Photograph taken July 5, 1957. 42. 43. Bow QEBBQE ... <0 Box 038333: .4. <3 Bow 205538025 u <59 mENmuPE 332: u :2 ll|||l :1: 3m ow .3 o? S .3 emu 8 .3 EN 8.2 mmm .8330 @820. E .2 SN mm .2 SN S .2 o2 g .: Sm B .2 wmm .wcznmmm Eu Ham. mo? who mo? mum modo mum mmfio who mm? who -5.qu -BoE -Efiom -BOE -..—anon -305 -5.qu -26; -Efiom -263 Ema 8: 3580 2:: 8: < $2 .2 5&3 8 $2 .H as; 69a .5230 9530. cam .mfiemmm TED 53m. $9530 «Snwfifimm mo 3356mm cam mug/OE mo H3522 so muoufizwom 5386 53.30 mo 83mm XH Mia/E. 44. The significances of the means for the number of flowers were found to be as follows: For cultivar 'Star Girl Seedling': GA significantly greater than 1AA, TIBA. For cultivar 'Queen‘s Cushion': GA significantly greater than 1AA, MH, TIBA, Control. Control significantly greater than 1AA. The significances of the means for the number of peduncles were found to be as follows: For cultivar 'Star Girl Seedling‘: GA significantly greater than all other groups. For cultivar 'Queen's Cushion': GA significantly greater than all other groups. Effect on Lasting Quality of Flowers Lasting quality of the flowers was recorded for each treatment for each variety (Table X). An analysis of variance was made from the result- ing data and the significance of each treatment was determined. . The significances of the means were found to be as follows: For cultivar 'Star Girl Seedling': Control significantly greater than GA. MH, 1AA, TIBA 45. TABLE X Effect of Certain Growth Regulators on Lasting Quality of Saintpaulia Flowers. Average Number of Days Flowers Lasted (Means of 15 Cultivar Replicates) . MH TIBA 1AA GA Control 100 ppm 25 ppm 100 ppm 100 ppm 'Star Girl Seedling' 10. 0 10. 2 10. 0 7. 8 ll. 0 'Queen's Cushion' 13. O 13. 2 l4. 2 l3. 4 l3. 6 MH = maleic hydrazide TIBA =2 triiodobenzoic acid 1AA = indoleacetic acid GA = gibberellic acid. 46. TIBA significantly greater than GA. 1AA significantly greater than GA. MH significantly greater than CA. For cultivar ‘Queen's Cushion': 1AA significantly greater than MH, TIBA, GA, Control. Control significantly greater than MH, TIBA. GA significantly greater than MH. Morphological Changes In addition to the data presented, observations were made on other external features of the two Saintpaulia cultivars. With the exception of the gibberellic acid treated plants, no other external changes were observed. Growth of the various plant parts seemed normal in the case of untreated plants, 25 parts per million triiodobenzoic acid, 100 parts per million maleic hydrazide, and 100 parts per million indoleacetic acid. Other external changes on gibberellic acid treated plants were very noticeable when they occurred. The first two to three buds showing color at time of spray appli- cation seemed to develop into larger flowers, but buds later in developing seemed to produce flowers which were smaller than normal. This seemed to be true of both varieties. The blue-purple color of the double-flowered cultivar 'Queen's 47. Cushion', did not seem to be changed. The flower color of the single-flowered cultivar 'Star Girl Seedling' is blue-purple and white. Normally the pattern formed by the colors in the latter cultivar is quite variable. Sometimes all flowers on one inflorescence are white, while those of another inflorescence of the same plant may all be a solid blue-purple. Flowers having various patterns of blue-purple and white are the usual, but patterns may vary. In patterned flowers the blue-purple color is usually toward the edges of the petals. From observation it was difficult to determine whether or not color pattern of the flowers appeared to have been modified. They did not appear to be when a comparison was made with untreated plants. The most striking observed change in the gynoecium was a change concerning the style in the cultivar 'Star Girl Seedling'. The style is nor- mally slightly lobed (22). On the 100 parts per million gibberellic acid treated plants, flowers appeared with styles which were deeply split (Figure 19). In normal styles there is a line extending a few millimeters from the grove of the lobed stigma toward the ovary, but there is no distinct separa- tion of the tissue (Figure 18). Cross sections cut with a razor blade show that these lines of separa- tion were in the same position that the cross walls of the bilocular ovary is in. This suggests a bicarpellate ovary which may have been separated in more primitive forms. Figure 18. Style of Saintpaulia cultivar 'Star Girl Seedling' from flower of untreated plant. Arrow indicates grove extending a few millimeters above the stigma. X20. 48. 49. _ ..w'_ Figure 19. Deeply split style from flower of 100 parts per million gibberellic acid treated Saintpaulia cultivar 'Star Girl Seedling'. X20. 50. Another change involving the gynoecium is a change of position of the style. H. Wendland (37), who originally described the genus Saintpaulia, noted that the styles were either left-handed or right-handed. Many styles on the gibberellic acid treated plants of cultivar 'Star Girl Seedling' extended straight out of the corolla tube instead of turning either to the right or left. Changes also occurred in the androecium. Normally the anther apices are united by a small tissue-fusion (39). Many anthers in flowers of gibberellin-treated plants were not united. This change seemed to be asso- ciated with change in position of the styles. A few peloric flowers of cultivar 'Star Girl Seedling' were observed among each group of plants, but the frequency of occurrence seemed greater in the gibberellic acid treated plants. Pedicels, peduncles and pedicel bracts were very definitely elon- gated as in Figures 20 and 21, as were leaf blades and petioles. This was observed on both cultivars. Figures 20 and 21 also show the effect on chang- ing the angle of the leaves to the axis. Gibberellic acid treated plants had leaves which tended to angle toward the vertical axis. This effect was notice- able 7 days after the first spray application. Leaves of both cultivars of Saintpaulia .showed the effect of gibber- ellic acid as in Figures 22 and 23. The general effect was one of elongation of both blade and petiole for each cultivar. Leaf apices became more acute _ . __ __.44._r‘_ 51- Figure 20. Saintpaulia cultivar ‘Star Girl Seedling' showing the effect of gibberellic acid at 100 parts per million on the growth habit. Left: control. Right: 100 parts per million. 52. Figure 21. Saintpaulia cultivar 'Queen's Cushion' showing the effect of 100 parts per million gibberellic acid on growth habit. Left: control. Right: 100 parts per million. 53. than on normal leaves. Leaf bases tended to become narrower. In cultivar 'Star Girl Seedling' leaf bases of the blades tended to gradually narrow into the petiole which, in turn, became leaf-like and gradually merged into a normal petiole as in Figure 23. Three weeks after the final treatment with gibberellic acid leaves of both cultivars became lighter in color. This was corrected with an application of water soluble commercial fertilizer, which was applied in equal amounts to all plants in the experiment. ing the effect of 100 parts per million gibberellic an; Upper set: control. Lower set: from plants treated ‘ ' 100 parts per million gibberellic acids!» ‘2; -.- 1 _, , , _ .. ‘___.-__' ‘ r H . , r _ ..7 . . . A. ...- .. ._. _,_, .-..-___. 55. Figure 23. Leaves from Saintpaulia cultivar 'Queen's Cushion‘ showing the effect of 100 parts per million gibberellic acid. Upper row: control. Lower row: 100 parts per million. _ dig—=7; 7- DISCUSSION OF RESULTS Rooting Leaf-Petiole Cuttings Rooting response of leaf-petiole cuttings, obtained from plants treated with various chemicals, was significantly different in the two varie- ties. However, rooting behavior of leaf-petioles of control plants was similar in both cultivars, indicating that chemical treatments were responsible for the induced response as exhibited by treated plants. For example, in cultivar 'Queen's Cushion', the rooting pattern of leaf-petiole cuttings treated with - maleic hydrazide, triiodobenzoic acid, indoleacetic acid and gibberellic acid was different in each case. In the heavily rooted class of cuttings (Table III) the treatments ar- ranged in descending order from the large st number of cuttings rooted to the smallest number rooted were: control, maleic hydrazide, indoleacetic acid, triiodobenzoic acid and gibberellic acid, all of which were found signi- ficantly different by chi-square analysis. In cultivar 'Star Girl Seedling', only gibberellic acid treatment yielded comparatively fewer roots, while there was no significant difference in root growth from other chemicals, although the arrangement of treatments in the heavily rooted class of cuttings was similar in order to those of the cultivar 'Queen's Cushion'. 57. Leaf-petiole cuttings obtained from the gibberellic acid treated plants of each cultivar produced the least number of rooted cuttings in com- parison with the other treatments. Results indicated that (1) cultivar differences are of major import- ance in chemical treatments, which tend to influence the morphology of plants: and (2) 100 parts per million of gibberellic acid as used in this ex— periment, is not conducive to rooting leaf-petiole cuttings of Saintpaulia cultivars 'Star Girl Seedling' and 'Queen's Cushion'. Pollen Germination The average germination of pollen from treated plants of 'Star Girl Seedling' was significantly different from the average pollen germina- tion of the controls. Pollen from flowers of control plants averaged 4 per- cent higher in germination than pollen from the triiodobenzoic acid treated plants; 5. 4 percent higher than from the indoleacetic acid treated group; 6. 2 percent higher than from the gibberellic acid treated group; 6. 8 percent higher than from the maleic hydrazide treated group. Thus, pollen from untreated plants germinated significantly better than pollen from treated plants. Since pollen of both the treated and untreated plants germinated under the same environmental conditions, it may be postulated that the three spray applications of growth regulators used at their specific concen- trations inhibited germination of pollen in some manner, perhaps by affect- ing the chemical or physical structure of the pollen. Pollen from gibber- ellic acid treated plants appeared to be smaller than that of any other. No other abnormalities were noted. Since higher germination percentages have been recorded for other plants, for example, 100 percent for Milla biflora a monocotyledon, and 100 percent for Tropaeolum majus by germinating their pollen in vitro (1) it was reasonable to expect higher germination in the Saintpaulia cultivar 'Star Girl Seedling'. This was not the case. Either the environmental conditions were not optimum for best germination or something inherent in the pollen prevented its germination. It may have been a combination of both factors. Ehrlich (11) found the degree of sterility of pollen from six cultivars of Saintpaulia at anthesis to range from 2. 2 percent to 40 per- cent. The pollen of 'Star Girl Seedling' may be sterile to some extent. Growth Growth as expressed by maximum diameter of the rosettes of leaves of each cultivar is shown in a series of graphs (Figures 7 to 15). Unconnected dots represent the average maximum diameter of 15 plants included in each treatment. The line connecting these dots represents the mean of these averages as expressed in inches. 59. An inspection of the growth curves for cultivar 'Star Girl Seedling' and ‘Queen's Cushion' shows that in general all treatments except the gib- berellic acid treatment tend to follow the line of the control. The growth rate of gibberellic acid treated plants is much greater. Thus, the rate of growth as measured by maximum diameter was greatly increased by the gibberellic acid treatment, while the growth rate of all other treated groups tended to follow the growth rate of untreated plants. Flower and Peduncle Production An analysis of the flower data shows significantly more flowers produced in the gibberellic acid treated plants of cultivar 'Queen's Cushion' than in any other treated group, including the control plants. There were no significant differences between averages of the maleic hydrazide, tri- iodobenzoic acid and control group. The number of peduncles for this cultivar during the same period was found to be significantly greater for the gibberellic acid treated group alone. Thus, there was a significantly greater amount of flowers and pe- duncles produced by the gibberellic acid treatment in the case of cultivar ' Queen' 8 Cushion'. For the cultivar 'Star Girl Seedling' the gibberellic acid treated 60. plants produced a significantly greater number of flowers than the indole- acetic acid and triiodobenzoic acid treated groups, but the number of flowers produced was not significantly greater than in the check or in the maleic hydrazide groups. The peduncles of the gibberellic acid treated groups were significantly greater in number than any other treatment, including the check. While there was a significantly greater number of peduncles produced by gibberellic acid treated plants, the total number of flowers produced was not significantly greater than the check. 'Lasting Quality of Flowers The lasting quality of the flowers of 'Star Girl Seedling' was signi- ficantly greater in the untreated plants. Triiodobenzoic acid, indoleacetic acid, and maleic hydrazide treated groups produced flowers which lasted a significantly greater time than those of the gibberellic acid treated group. It thus appears that the gibberellic acid treatments were harmful to the lasting quality of flowers of cultivar 'Star Girl Seedling'. In cultivar 'Queen's Cushion' only the indoleacetic acid treated group of flowers were significantly greater than the untreated group in last- ing quality. Since there is a difference between these two cultivars of _S_a_in_t_- paulia in respect to time the flowers last after treatment with maleic hydra- 61. zide, triiodobenzoic acid, indoleacetic acid, and gibberellic acid, it follows that different cultivars from the same species of plants may respond differ- ently to chemical treatments. Morphological Changes As has been found for other plants (43), the major formative modi- fications induced by certain growth regulators in two cultivars of Saintpaulia are changes in flowering habit, size, shape, pattern and venation of organs. Thus, shape and position of styles of the cultivar 'Star Girl Seedling' were modified by treatment with gibberellic acid. The position of anthers was also modified. Leaf shape of both varieties was modified as well as venation of 'Star Girl Seedling‘. However, these effects were not noted in the group treated with indoleacetic acid, maleic hydrazide, or triiodobenzoic acid. This must be because the plants were unresponsive in morphological changes to the concentration used. It is probable that higher concentrations would have had more effect in bringing about morphological changes. The changes brought about by gibberellic acid at 100 parts per million were certainly not desirable in adding to the beauty of the plants. Gibberellic acid at 100 parts per million caused the plants to look ungainly through general elongation of plant parts. Experimental results with geraniums indicate lower concentrations of gibberellic acid may be beneficial. Thus, Lindstrom and Wittwer (19) found that 10 parts per million of gibberellic acid was beneficial to lasting quality of a white cultivar of geranium. 62. 63. SUMMARY The cumulative effect of three foliar applications each of 100 parts per million maleic hydrazide, 100 parts per million indoleacetic acid, 100 parts per million gibberellic acid, and 25 parts per million triiodobenzoic acid on rooting responses of leaf-petiole cuttings of two cultivars of Saint- paulia 'Star Girl Seedling' and 'Queen's Cushion' were studied. Cuttings from sprayed and unsprayed plants were rooted in sand at 75’F, and after 34 days were removed and grouped into four classes (not rooted, lightly rooted, intermediately rooted, and heavily rooted) for evaluation. Rooting response of leaf-petiole cuttings in the control groups for each cultivar were as good, and in most cases better, than those from the chemical treated groups for each variety. In each cultivar the 100 parts per million gibberellic acid treated cuttings had the least number of cuttings rooted. Treatments producing the heavily rooted cuttings arranged in descending order from the largest number of cuttings rooted to the smallest were: control, maleic hydrazide, indoleacetic acid, triiodobenzoic acid, and gibberellic acid. The cumulative effect of three foliar applications each of 100 parts per million maleic hydrazide, indoleacetic acid, gibberellic acid, 64. and 25 parts per million triiodobenzoic acid on pollen germination, the number of flowers, number of peduncles, lasting quality of flowers, change of external parts in Saintpaulia plants were also studied. Germinating responses of pollen in the control group for cultivar 'Star Girl Seedling' were significantly greater than those from the chemical treated groups of the same cultivar. The average percentage germination for the untreated group was 10. 6 percent, which was significantly greater than the percentage germination for the following groups: 6. 6 percent for the 25 parts per million triiodobenzoic acid group; S. 2 percent for the 100 parts per million indoleacetic acid group; 4. 4 percent for the 100 parts per million gibberellic acid group; and 3. 8 percent for the 100 parts per million maleic hydrazide group. Pollen germination responses of the cultivar 'Queen's Cushion' were not investigated because pollen was seldom produced. Maximum diameter measurements show that growth rate of both varieties was greatly increased by the 100 parts per million gibberellic acid treatment, while all other treated groups tended to follow the normal growth pattern as expressed by the untreated groups. Flowering response of the two cultivars differed significantly in regard to chemical treatments. Flower production in the cultivar 'Queen's Cushion' treated with 100 parts per million gibberellic acid, with an average 65. of 489 flowers per plant, was greater than for any other chemical treated group or the untreated group. Flower production in untreated plants, an average of 343 flowers per plant, was only slightly greater than those on the 100 parts per million indoleacetic acid treated plants, which had an average of 250 flowers per plant. The 100 parts per million gibberellic acid treated plants of culti- var 'Star Girl Seedling' produced a significantly greater number of flowers, an average of 281 flower 3 per plant, than the 100 parts per million indole- acetic group, an average of 199 flowers per plant, and the 25 parts per million triiodobenzoic acid treated group, an average of 217 flowers per plant. The number of flowers in the gibberellic acid treated group, 281, was not significantly greater than those of the untreated group, 231, or the 100 parts per million maleic hydrazide group with 238 flowers per plant. The response of number of peduncles per plant in the 100 parts per million gibberellic acid treated groups was significantly greater than those of the other groups in cultivar 'Star Girl Seedling' and in cultivar 'Queen's Cushion'. Therefore, the 100 parts per million gibberellic acid treatment significantly increased the average number of peduncles per plant above those of untreated plants and the other chemically treated plants. 66. Flower lasting response of the untreated plants of cultivar 'Star Girl Seedling' was significantly greater than the flower lasting response of any of the treated groups. The response of the flowers of cultivar 'Queen's Cushion' to 100 parts per million indoleacetic acid was significantly greater than for all other groups. Formative modifications resulting from chemical treatment were apparent only as a result of treatment with 100 parts per million gibberellic acid. Modifications common to both cultivars included changes in leaf shape, elongation of petioles, peduncles and lamina, changes in the angle of emergence from the axis of the leaves due to an upward movement of the entire leaf toward the vertical axis of the plant. Modifications specific to cultivar 'Star Girl Seedling' were: changes in style position and shape, separation of anthers, and a tendency toward greater production of peloric flowers. 10. ll. 12. 13. 6?. LITERATURE CITED . Addicott, F. T. 1934. Pollen germination and pollen tube growth as influenced by pure growth substances. Plant Physiol. 18: 270-279. . Audus, L. J. 1953. Plant Growth Substances. Interscience Publishers, Inc. New York. 465 pp. . Avery, G. S. Jr., and E. B. Johnson. 1947. Hormones and Horti- culture. McGraw-Hill Book Co. New York. 268 pp. Beck, G. E., and]. R. Vaughan. 1949. Botrytis leaf and blossom blight of Saintpaulia. Phytopath. 39(12): 1054-1056. . Bohning, R. H., and C. A. Burnside. 1956. The effect of light inten- sity on rate of apparent photosynthesis in leaves of sun and shade plants. Amer. Jour. Bot. 43(8): 557-561. Brock, R. D. 1951. Hormone induced pear-apple hybrids. Heredity 8: 421-429. . Clark, H. E., and K. R. Kerns. 1942. Control of flowering with phytohormones. Science 95: 536-537. Diimmer, R. A. 1912. Peloria in Saintpaulia ionantha, Wendland. Ann. Botany 26: 946-947. . Duncan, D. B. 1955. Multiple range and multiple F tests. Biometrics 2 (1): 1-41. Eberle, P. 1956. Cytologische Untersuchungen An Gesneriaceen I. Chromosoma. 8: 285-316. Ehrlich, H. G. 1956. Cytological investigations of some African Violet varieties. African Violet Magazine 9 (3): 77-84. Galston, A. W. 1947. Effect of 2, 3, S-triiodobenzoic acid on growth and flowering of soybeans. Amer. Jour. Bot. 34: 356-360. Gray, R. A. 1957, Alteration of leaf size and shape and other changes caused by gibberellins in plants. Amer. Jour. Bot. 44: 674-682. 68. 14. Hanchey, R. H. 1955. Effects of fluorescent and natural light on vege- tative and reproductive growth in Saintpaulia. Proc. Amer. Soc. Hort. Sci. 66: 378-382. 15. Hemphill, D. D. 1949. The effects of plant growth regulating substances on flower bud development and fruit set. Univ. Missouri Agr. Exp. Sta. Res. Bul. 433. 56 pp. 16. Hildreth, A. C., and J. W. Mitchell. 1939. Spraying is a new method of applying root-promoting substances. F lorists' Rev. p. 13, May 25th. 17. Hitchcock, A. E., and P. W. Zimmerman. 1935. Absorption and move- ment of synthetic growth substances from soil as indicated by re— sponses of aerial parts. Contrib. Boyce-Thompson Inst. 18. Hollings, M. 1955. Physiological ring pattern in some Gesneraceae. Plant Path. 4(4): 123-288. 19. Jones, M. R. 1952. Propagating Saintpaulias. The Gardners Chronicle (London) 132: 134-135. 20. Kelley, J. D. 1957. The effect of selected chelating agents, growth regulators, respiratory inhibitors and antibotics on the life of cut flowers with special reference to Antirrhinum majus. Ph. D. Thesis. Michigan State University. 21. Kiplinger, D. C. 1955. Greenhouse Potted Plants. Ohio Agr. Exp. Sta. WooSter. p. 43. 22. Kohl, H. C. Jr. and others. 1956. Effects of various ions and total salt concentrations on Saintpaulia. Proc. Amer. Soc. Hort. Sci. 68: 545-550. 23. Leopold, A. C. 1955. Auxins and Plant Growth. Univ. Calif. Press. 354 pp. 24. Lindstrom, R. S., and S. H. Wittwer. 1957. Gibberellin and higher plants: IX. Flowering in geranium (Pelargonium hortorum). Mich. Agr. Exp. Sta. Quart. Bul. 40(1): 225-231. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 69. L00, T., and T. Hwang. 1944. Growth stimulation by manganese sulfate, indole-3-acetic acid, and colchicine in pollen germination and pollen tube growth. Amer. Jour. Bot. 31: 356-367. Moore, H. E. 1957. African Violets, Gloxinias and Their Relatives. MacMillan Company. New York. 323 pp. Naylor, A. W. 1950. Observations on the effects of maleic hydrazide on flowering of tobacco, maize, and cocklebur. Proc. Nat‘l Acad. Sci. 36: 230-232. Naylor, E. E., and B. Johnson. 1937. A histological study of vegeta- tive reproduction in Saintpaulia ionantha. Amer. Jour. Bot. 24: 673-678. Reed, S. C. 1954. African violet genetics. Jour. Heredity 45: 225- 230. Rogers, 0. M. 1954. Chromosome counts in the Gesneriaceae. Baileya 2: 14-18. Seely, R. C. , and R. L. Wain. 1955. Studies on plant growth-regu- lating substances. IX. Investigations with pollen extracts and synthetic growth substances on hop plant (Humulus lupulus, L. ). Ann. App. Biol. 43: 355-365. Skoog, F. 1951. Plant Growth Substances. Univ. Wisconsin Press, Madison. 467 pp. Smith, D. E. 1955. Evaluation of chemical rooting agents in rooting Saintpaulias. African Violet Magazine 8 (4): 48-54. Smith, P. F. 1939. The influence of 3-indoleacetic acid on pollen germination. Science 90: 164. Snedecor, G. W., and W. G. Cochran. 1957. Statistical Methods. The Iowa State College Press. Ames, Iowa. 534 pp. Stinson, R. F. 1954. The effect of light intensity on the initiation and development of flower buds in Sainglaulia ionantha. Proc. Amer. Soc. Hort. Sci. 64: 459-467. 37. 38. 39. 40. 41. 42. 43. 44. 45. 70. Stinson, R. F. , and R. S. Lindstrom. 1957. Saintpaulias; The effect of temperature of the rooting medium upon root and shoot forma- tion. The Michigan Florist 310: 7. van Overbeek, J. 1946. Control of flower formation and fruit size in the pineapple. Bot. Gaz. 108: 64-73. Warner, G. C. , and F. W. Went. 1947. Rooting of Cuttings with Indoleacetic Acid and Vitamin 31' Plant Culture Publishing Co. Pasadena, Calif. Wendland, H. 1893. Saintpaulia ionantha. Gartenflora. 42: 321-324. Wilson, J. H. 1898. Observations on the flowers, fruit and seedlings of Saintpaulia ionantha, Wend. Botanisch. Jaarboek. pp. 87-109. Wittwer, S. H., L. L. Coulter, and R. L. Carolus. 1957. A chem- ical control of seedstalk development in celery. Science 106: 590. Zimmerman, P. W. 1951. Formative effects of hormone-like growth regulators. pp. 175-183 in Plant Growth Substances, F. Skoog (Ed.). Univ. Wisconsin Press. Madison. , and A. E. Hitchcock. 1939. Experiments with vapors and solutions of growth substances. Contrib. Boyce-Thompson Inst. 10: 481-508. 1942. Flowering habit and correlation of organs modified by triiodobenzoic acid. Contrib. Boyce-Thompson Inst. 12: 491-496. .... ... fl '! hf -. if", . -,: "w ~ ~ ‘ ‘7 E., 3 " I 5 3 ~- ~ 1»: ~.:' ML ifitry'ad Unit-- V‘ 196 774 lllllrllllllijlfllflljlm 3