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ENHANCED EMERGENCE IN CORN BELT GERMPLASM
FROM HOPI MAIZE

Edward Joseph Schantz

A THESIS
Submitted to

Midhigan State university
in partial fulfillment of the requirements

for the degree of

MASTER OF SCIENCE

Department of Crop and Soil Sciences
Plant Breeding and Genetics

1988

2/79ii7

ABSTRACT

NANCE!) BERGENCE IN CORN BELT GERMPLASM
FRCM HOPI MAIZE

By
Erhard Joseph Schantz

Hopi Maize is not represented in the background of elite Corn Belt
gennplasm. The drought resisting adaptations of Hopi Maize,
particularly its capacity to emerge fran deep planting, could be of
benefit for sane parts of the Corn Belt. Effectively incorporating
exotic material into Corn Belt inbred line development programs can
present difficulties. -

Hopi Maize was crossed to an elite, but poor emerging, Corn Belt
inbred to form a source population for inbred line developnent. $1
nursery rows were deep planted within a replicated emergence experiment .
Early test crosses were made with plants selected for agronomic type.
Material was advanced based on data analysis for emergence, selection
for agronomic type, and combining ability. This system appeared
effective for incorporating emergence and some other characters of Hopi
Maize relatively quickly and with only minor modifications of standard

commercial procedures using the Pedigree Selection Method.

TABLE OF CONTENTS

Page
List of Tables ................................................... iv
List of Figures ................... - ................................ v
Introduction ............. 1
Reviewof Literature .............................................. 3
MaterialsarxiMethods ............................................ 11
'Results .......................................................... 16
Discussion ....................... . ............................. ..23
Summary .......................................................... 30
List of References..... ............. ........... ........... .......31

111

LIST OF TABLES

Page
Table 1. Energence Experiments mtry Means. . ................... . .17
Table 2. ANOVA: 1986 Emergence Data. . ..................... . . ..... 18
Table 3. ANOVA: 1987 Emergence Data...... ..... ............. 18

Table 4. 1987 Emergence Experiment Means Comparisons and Ranking.19
Table 5. Yield Trial Data for Specific Hybrids (SCA) ............. 20

Table 6. Inbred Line Evaluation Index (GCA) ................ . ..... 22

iv

LIST OF FIGURES

Page
Figure 1. First Internode Elongation of Hepi Parent..... .......... 26

Figure 2. First Internode Development of Hepi x Oh 43-16 Line.....27

Figure 3. Failure of Emergence of Ch 43 Parent Seedlings .......... 28

INTRODUCTION

Plant breeders recognize the importance of maintaining genetic
diversity in crop breeding programs. Diversity is critical in providing
basic variability for effective gain fran selection for currently
important plant traits and performance, and in providing for potentially
valuable future selection. Crop plant germplasm represents a valuable
resource, even when it confers no apparent imnediate benefit to a
breeding program.

Acquisition and preservation of new germplasm may be followed by
integration into on-going breeding programs where new genes may confer a
specific improvement or may enhance the genetic baciagrmrnd of the
breeding material. Vulnerability due to a narrow genetic base may
decrease. .

As a standard approach using the Pedigree Selection Method,
adapted varieties or lines of corn are crossed to generate source
populations for inbred line development. Crosses of adapted by exotic
material with subsequent inbred line developnent could be effective as a
method of enhancement breeding both for the direct developmnt of new
inbred lines from $1 populations and for the creation of new populations
for recurrent selection. This approach has not been much used in
cannercial corn breeding mainly because of the additional time and
difficulty involved. The omnrrercial corn breeder is generally under a
time pressure to quickly develop improved inbred lines for new higher
yielding hybrid canbinations. This is most efficiently achieved by

1

working with crosses of elite adapted material. Despite the increasing
degree of interrelationship among elite Corn Belt inbred lines,
improvanent and gain fran selection for yield is still being made.
Public corn breeding program have traditionally been more
concerned with population improvement and germplasm enhancement .
Unfortunately, many of the public corn breeding program no longer have
the funding to continue the type of long term conventional field
breeding work involved in program of pepulation improvement and
recurrent selection. A breeding approach is needed that can generate
improved, and genetically enhanced, inbred lines or breeding material
fran exotic sources according to an acceptable commercial timetable.
This research was an effort to incorporate germplasm fran Hopi
Maize into a Corn Belt inbred line (an elite selection from an Oh 43
type). Specifically, the goal was to incorporate the superior anergence
capacity of the Hopi Maize into the poor energing, but high yielding, Oh
43. The breeding systan anployed was evaluated for effectiveness in
developing enhanced breeding material. The basic procedure was a series
of crosses of Hopi Faize and the Oh 43 type, followed by two generations
of sib—mating. Inbred line development by the Pedigree Selection Method
was then undertaken. Selecton was intense for agronomic plant type and
emergence capacity in the 31 (F2) generation. The Si nursery was
planted as a replicated energence experiment. The field research was at
the Dekalb—Pfizer Genetics, Inc. maize breeding research station at
Mason, Michigan. Field procedures were as close as possible to standard

procedures at that station.

REVIEW OF LITERATURE

Bram,Anderson, and 'mchwena (1952) emphasized that germplasm of
agricultural value may reside in sane southwest Indian maize. Many
varieties are extinct, but three fairly distinct varieties of Hopi Maize
are still maintained. These are not represented in the background of
any elite Corn Belt inbred lines.

Carter and Anderson (1945) classification southwest maize and it is
relatively simple compared to that of some other areas. The southwest
had been semi-isolated from other agricultural areas by geography and
climate, and little cultural exchange occurred with other areas. Fields
were few and often far apart in order to be near moisture. Well
differentiated local varieties could develop.

Brown and Goodman (1977) and tangelsdorf (1939) reported the
developnent of southwest maize. There were at least three different
sources, or recanbinations of races. First there was the pre—historic
Basketmaker race from Mexico. Modern varieties of this are called
Pima-Papago. It has 10—16 kernel rows, floury endosperm, tillering, and
purple coloration to the leaf sheaths. Chapalote and Reventador are
related to it. Two later types were involved. One, the Mexican
Complex, was a tapered ear dented kernel type from the Mexican Plateau.
The other was the Eastern Complex with strong arching leaves, large
basal portion of the ear and wide kernels in eight rows. The Eastern '
Complex is found in Guatemala and in the flints of the eastern United
States. According to Carter and Anderson (1945) , the Basketmaker race
was modified toward the Mexican Complex with an increase in row number .

and denting of the kernels. Around 1200-1300 A.D. the Eastern Complex

came into the southwest from the southeast and greatly modified
southwest maize. Among present day southwest Indian maize, Hopi Maize
shows the least Eastern Complex influence.

Galinat and Campbell (1967) disputed the southeast origin for the
Eastern Complex, believing instead that an eight rowed maize race (Maiz
de Ocho) spread from the southwest into the central plains and then to
the northeast. They believe Maiz de Ocho entered the evolution of
southwest maize around 700 A.D. , and conferred better productivity and
easier milling to southwest maize. They state that it is, in modified
form through the Northern Flints, one of the components responsible for
the heterosis in Corn Belt hybrids. ‘

Brown, Anderson, and Tuchwena (1952) compiled data on three major
Hopi Maize varieties: White Flour, Blue Flour, and Kolaorra (purple). The
White Flour variety shaved stronger Eastern Complex and Mexican Complex
influence than the Blue Flour. The Southwest Semident race (somewhat
similar to the Northern Flints morphologically) is represented in most
collections of Hopi White Flour since the Hopi do not separate the
semident and flour forms of their white naize. Kokana showed only a
slight Eastern Canplex influence. Kokana is the most primitive, and
closest relative of the prehistoric Basketmaker race.

Brown et al. (1952) described Hopi plant and ear types. The Blue
Flour variety attains a height of about 4 feet and averages 10 or more
tassel branches with a long central spike. The leaves appear long in
relation to the height of the plant. The kernels are narrow and vary in

row number fran 10-20. Fishy ears show a distinct basal cqnpression.

Kernel color is from a white endosperm, blue aleurone, and colorless
pericarp. The intensity of the blue color is variable.

The White Flour variety is similar in maturity to Blue Flour.

Plants are shorter and lighter green in color due to lack of
anthocyanin. It tillers extensively and shows reduced internode lengths
above the ear. Like Blue Flour, it has a many branched tassel with a
long central spike but has generally wider kernels and wider shank. It
does not show the distinct basal compression of Blue Flour. Kernel row
number usually exceeds 14. Kernel color is from a white endosperm and a
colorless pericarp and aleurone. Some kernels may show a light pink
flush to the pericarp.

The Kokoma variety is the least grown of the three major varieties.
The ears resemble the cigar shaped Basketmaker type. Kernel row rmmber
varies from 12-14. Kernel color is due to an intense cherry pericarp.
There is a pronounced purplish color to the leaf sheaths and tassels.
The purplish husks are used as a source of dye.

Anthocyanin in the aleurone layer of the endosperm gives the blue
color to Blue Flour and is due to the dominant genes A1, A2, C, R, and
Pr. The characteristic allele for Blue Flour is designated Ra in the R
allele series. In most stocks of Blue Flour there are admixtures of 2
other alleles, m1 and Rst, which give white seeds with a blue tip and
speckled seed. In Write Flour the kernels are mostly white due to an
inhibitor gene. Variants may show a flush of purple or rose/pink. In
Kokana purple anthocyanin in the pericarp is due to a conbination of the
rch cherry allele of the R series and the P1 gene for plant color which

gives much pigment to the sheaths, husks, tassels, cob, and pericarp.

The capacity of Hopi Maize to emerge well from deep planting was
the primary reason for its use in this breeding program. One of the
first to observe this characteristic was Collins (1915) . He reported
that an important factor in the drought resistance adaptation of Hopi
Maize is its capacity to force the growing shoot of the seedling to the
soil surface even when planted at a depth of 12 inches or more. When
planted this deep, other varieties die before reaching the surface.

Benson and Reetz (1985) and Kiesselbach (1949) described emergence
in naize. It is accomplished through a combination of coleoptile growth
and mesocotyl (first internode) elongation. The mesocotyl is the
structure between the scutellar and coleoptile nodes. The coleoptile
node is the crown, or growing point, and is the site of nodal roots
(permnent roots) formation. The coleoptile node is brought to about
one inch below the soil surface by first internode elongation. If a
kernel is planted one inch deep, emergence will be entirely by
coleoptile growth. With deeper planting, the first internode elongates
to bring the coleoptile close enough to the soil surface to make
emergence possible. The first internode elongates rapidly by
intercalary growth at its upper end. If planting is deeper than the
first internode can elongate, or the coleoptile tip ruptures
undergrormd, emergence does not occur.

Collins (1915) reported that it was through first internode
elongation that the Hopi Maize shoot was able to reach the soil surface
from deep planting. He reported observations of Hopi first internodes
over 36 centimeters in length. He found variation among maize varieties

for first internode elongation, but relatively constant values within

varieties. He observed Hopi Maize plants with no adventitious root
formation. The seminal roots remained primary throughout the life of
the plants rather than diminishing as occurs with most maize varieties.
Collins speculated that this downward root system developed to reach
moisture in a dry environment.

Inge and Loomis (1937) reported on growth of the first internode in
maize. Theyplantedseedsat varyingdepths insandinagreenhouseand
found first internode lengths varied with depth of planting and with
varieties. Entries in their experiments included Hopi Maize and Corn
Belt material. They observed the extrene development of the first
internode in the Hopi Maize relative to the other varieties and stated
that this explained its capacity to emerge when deeply planted. If seed
was germinated in darkness, the first internode of the axis elongated
rapidly and other shoot tissue developed slowly. Mien the coleoptile
tip emerged, first internode developnent ceased, and plmnule developnent
accelerated. Formation of roots began at the coleoptile node. They
reported that first internode elongation is due to cell division in the
region Just below the coleoptile node. In early developnent this
division was dominant over cell division in the inhibited apical
meristem. After emergence, when the first internode ceased development,
the shift to plumule growth was irreversible.

Troyer (1964) observed maximim first internode lengths over 24 cm.
for deep field planted Hopi Maize in Minnesota. He found a twin
seedling showing a total of over 36 cm. of first internode development
from an average amount of endosperm. He concluded that factors other

than endosperm reserves limit maximum first internode elongation.

Troyer investigated the inheritance of the long first internode trait in
Hopi Maize. He identified three chromosome arms (short arm of
chronoscme three, short arm of chronosome six, and short arm of
chrcmosane nine) as regions bearing genes that affect first internode
developnent. The geies conditioning the long first internode in Hopi
Maize expressed sane degree of dominance over their alellomorphs in
crosses with the Corn Belt inbred line A188.

An early examination of Hopi Naize was conducted by the Arizona
Agricultural Experiment Station (Clothier, 1913). Tests were conducted
over three years, in different locations and soil types, with different
maize varieties including two Arizona Indian varieties described as
"Blue Aztec" and "White Aztec" (Hopi Blue Flour and White Flour). In
the second year a deep planting of four to nine inches was undertaken,
resulting in poor stands except for the Blue and White Aztec types which
gave "medium" stands regardless of soil type. Clothier concluded that
none of the varieties offered great pranise for that area.

More receitly, Day, Grove, and Thompson (1972) compared twenty
maize varieties fron the Arizona maize collection including Arizona
Indian flour types and selections from the Mexican June Complex (white
dent type introgressed with northwest Mecican flour maize). They found
significant differences in height, leaf length and width, maturity,
grain volmte weight, and other characters. In particular, the Arizona
Indian maize was earlier, had longer leaves, more stalks per plot
(tillers), and higher grain volume weights than selections from the

Mexican June Complex.

Day (1986) reported on the formation, and registration, of a maize
population adapted to the arid, irrigated environment of the southwest
United States, which included Hopi Maize germplasm in its background.
Maize collections were made on Arizona Indian reservations from
1956-1968. Equal numbers of seeds of selections of flour and dent types
and selections fran the Mexican June Complex were planted at the Mesa
Agricultural Ceiterin 1960. The Mexican June selections were detasseled
and crossed with flour and dent pollen. Seed on the Mexican June was
bulked to form the original population. This seed has been planted in
isolation and open pollinated for 23 years in an irrigated area of
southern Arizona. Seed of this "Arizona Arid Environment Maize
Germplasm" was obtained from Day and planted at Mason, Michigan in 1986
for observation. Seed of Hopi Maize ( P.I. #213734 USA-IA, Hopi Tribe)
obtained fran the Regional Plant Introduction Station at Ames, Iowa was
planted for canparison. The Arizona germplasm was much later in
maturity and very different in plant type fran the Hopi material. Seed
of Hopi Maize fran the Iowa Plant Introduction Station was used in this
breeding work and thesis research. No information on the specific
background, composition, or first internode elongation of the Hopi Maize
population was available.

Brown and Goodman (1977) and Wallace and Brown (1956) noted that
most of the corn (_2.';e_a_ m L.) germplasm in the United States today is
derived from a mix of only two major antecedent races of corn (Northern
Flint and Southern Dent). This represents only 2—596 of the total
variation available. Additionally, many of the indigenous corn

varieties of the United States were replaced by hybrids prior to

10

organized germplasm preservation, and have been lost. Only a few of the
original Corn Belt open pollinated varieties are represented in the
background of present day Corn Belt material.

Considering this narrow geietic background, Hallauer and Sears
(1972) , Wellhause'i (1965), and others have emphasized the great
potential for the improvement of Corn Belt maize through the
incorporation of unadapted, or erotic, germplasm into corn breeding
programs. The increased diversity could eihance heterosis (Goodman,
1965) (Moll, Salhuana and Robinson,1962) , and could provide a broadened
genetic base for Corn Belt Deit race material.

In most eases erotic varieties can not be used directly in Corn
Belt breeding programs. The problem is to determine the best procedures
for integrating exotic material into breeding programs. Various methods
of population improvenent, including mass selection and recurreit
selection, and backcross breeding have been used for adapting or
integrating exotic material. Hallauer and Sears (1972) described an
alternative approach involving crossirg adapted and exotic maize. Their
study involved two successful methods. One was a mass selection schene
(for early silk energeice and lower ear placenent) for adapting a
population of the exotic variety Etc Canposite Maize. The other was a
series of crosses of Eto Carposite to adapted Corn Belt inbred lines.
This resulted in considerable genetic variability in the F2 generation

populations which could be effectively selected for desired traits. In

both cases usable breeding populations were established.

MATERIALS ANDMETHODS

Fifty seeds of Hopi Maize were planted in 1982 at the
Delalb—Pfizer Genetics research station in Madison, Wisconsin. The most
vigorois plants were crossed to an elite Oh 43 type inbred line. The
Hopi Maize seed and plants appeared to be a population formed through
the inter—varietal hybridization of various types of Hopi Maize.
Characteristics of all three major Hopi varieties described by Brown et
a1. (1952) were present, including multiple kernel coloration and
purplish leaf sheaths and tassels. The Oh 43 type inbred orginated from
the second cycle of selection within the Lancaster Sure Crop open
pollinated population. Lancaster Sure Crop was more of a flint type
than Reids Yellow Dent, the other major open pollinated variety in the
background of most Corn Belt inbred lines. The Oh 43 plants are medium
height with short internodes, light green leaves, relatively tight
husks, a thick white cob, and light yellow tassels and anthers.

Relative maturity is approximately 104 days and 0.5. heat units to
flowering approximately 1600 wher grown at Mason, Michigan. This inbred
has relatively poor seedling emergence. It is a poor pollen shedder,
especially under stress due to heat and lack of soil moisture.
Theseedfromthesecrosseswasbulkedandplantedto formasib-
mating population of 250 plants in 1983. Ears were harvested from 25
vigorous and healthy plants. A chain sib—mating procedure was used. No
plantwasusedasthepollenparentmorethanonce. Thisseedwas
bulked and formed a 1984 sib-nating population of 350 plants. Thirty
plants were selected and the seed bulked for a 1985 population of 500

plants. One hundred plants with good agronomic type were self

11

12

pollinated. Forty of the best plants were harvested and 25 of these 81
ears were selected for good agronomic type with yellow kernel color and
denting. Kernel color was of conncern in this research since selection
in the SO (F1) and Si generations for agrononic type included selection
of plants and seed with mainly yellowish kernel color annd "dentirg"
kernel character. Coe and Neuffer (1977) reported that inheritance of
the "dent" kernel form (which typifies field corn of the United States)
is ectrenely conplex and has been difficult to elaborate as a genetic
mechanism. Theinitial Oh43xHopi crossesweremadewiththeOh43as
the femaleandmost of theresultingseedwasdent type.

The 25 selected ears were planted ear to row for 1986 $1 populations
for inbred line developnent using the Pedigree Selection Method. They
also served as 25 separate entries in a randomized complete block
experiment with three replications designed to compare the relative
emergenceespacityoftheHopixOh43 $1 lineswiththeHopiandOh43
parents (making a total of 27 test entries).

Test crosses were made to selected plants in 11 of the 25 Si
families. These 11 families were selected for good agronomic type and
for superior emergence capacity. Testers were the inbred lines A632HT,
LH74, LHi46, and B73HT. A yield trial was conducted in 1987.

Bulked S2 seed from the 11 selected families was used to form 11
entries in a 1987 emergence experiment, including again the Hopi and Oh
43 parent entries. The 1986 and 1987 research was conducted at the
Mason, Michigan Dekalb-Pfizer research station.

The procedure was the same for both years' emergence experiments.

Thirty kernels of each entry were planted four inches deep over a 15

13

foot row. This corresponds to a 30,000/acre planting population.
Normal planting depth in the Corn Belt is one to two inches. It is not
possible to plant seed four inches deep'with conventional mechanical
planters. Hand planting was done using a soil sample boring tool. A
four inch core of soil‘was removed and one seed dropped into the hole.
The hole was filled.wuth finely worked adjacent topsoil and lightly
tamped. Soil type was a Capac clay loam with about a nine inch surface
layer. One replication was planted on each of three days, May 13, 14,
and 15, in both years. After emergence, the number of plants per plot
was counted. Families with the greater number of plants emerging were
assumed to have higher frequencies of the alleles for expression of the
trait.

The 1987 yield trial had 42 entries, 34 test crosses and eight
conunercial hybrids as checks. It was a randomized complete block design
*with.two replications at one location. It was pdanted.April 27 and
harvested on.0ctober 1. It was unirrigated, and planted.at normal
depth, wdth.30 inch rows and plot size of 1/500 acre. Planting
population.was 30,000/acre'with.subsequent thinning to 24,000/acre.
Plots were mechanically planted and harvested. Data were obtained for
‘yield, percent grain.moisture at harvest, early stand count, seedling
vigor, final stand count, and resistance to ear droppage and stalk and
root lodging. Early stand count gave a measure of emergence capacity.
Seedling vigor was a rating fron one to nine (highest). Lodging and ear
droppage resistance were counts expressed as percent not lodged, or
dropped, per plot. All data were then represented as a percent of mean

for the test, or as percent of mean for the check hybrids. Selection

14

indexes for mific Connbining Ability and General Combining Ability
were calculated by assigning economic weights for yield, percent
moisture, and resistance to lodging and ear droppage. Selection Indexes
were expressed as percent of test mean for GCA and percent of check
hybrid mean for SCA. An estimated relative maturity for each test cross
was derived from regression analysis based on the observed test moisture
and assigned relative maturity of the check hybrids.

The yield trial provided early testing information on combining
ability based on the principles for early generation testing as
described by Jenkins (1940), Sprague (1946) , and Sprague and Miller
(1952) . Early testing here permits heavy discarding of families based
on this first test. Future selection will be concentrated within and
among families with good conbining ability. Early testing research has
shown that the combining ability of heterozygous material in the early
stages of inbreeding does not differ significantly from the average
combining ability of the linnes eventually derived fron it.

The 1987 $2 selection nursery was separate from the emergence
experiment. One hundred plants were self pollinated. The 1987 yield
trial and emergence data on a family basis through pedigree records can
be used in selection for advancement to the 1988 $3 nursery. Some
selected lines may also be formed into populations for future recurrent
selection.

The analyses of variance for the two emergence enqneriments were
donne according to the procedure of Steel and Torrie (1980) . Comparison
of entry means was with the least significant difference, or LSD. For

the yield trial, analyses of variance and tests of significance were

15

performed with the procedures of Openshaw annd Troyer at Dekalb—Pfizer

Geneties .

RESULTS

Emergence experiment data is presented in Table 1 . Table 2 shows
analysis of variance for 1986. Highly significant entry differences
were found (F(26/52) = 12.9, p<.01). Comparison of paired entry means
for significant differences was with LSD( .01) . Emergence of the Hopi
parent was significantly better than the Oh 43 parent. None of the 81
entries showed significantly better emergence than the Hopi parent or
significantly lower emergence than the 0h 43 parent. The mean for the
test was significantly better than the Oh 43 parent. The 11 Si entries
selected for retesting were also selected for $2 advancement and yield
testing. Selectionn was based on agronomic type and on emergence
significantly better than the Oh 43 parent and not significantly lower
than the Hopi parent.

The 1987 emergence experiment (Table 3) also showed highly
significant entry differences (F.(12/24) = 21.56, p<.01). The Hopi
parent and all S2 families were significantly better emerging than the
0h 43 parent (Table 4). 1m families (11 and 16) were nnot significantly
lower than the Hopi parent. The ranked order of entries and comparisons
of means are slnown.

The 1987 yield trial data for the check hybrids and the six best
test crosses are presented in Table 5. Based on an economically
weighted selection index, six of the S2 lines performed well in specific
hybrid crosses, outyielding and standing better than some of the
comercial check hybrids. Column headings in Table 5 are selection
index, yield, percent moisture at harvest, yield to moisture ratio,

seedling vigor,early stand, final stand, nnot drop ears, nnot stalk lodge,

16

17

Table 1. Ehnergence Experiment Entry Means.

Nimnber Plants Emerged

 

 

Family 1986 (31) Selected 1987 (S2)
Hopi x Oh 43-1 20 +* x 11 +
Hopi x Oh 43-2 17 +

Hopi x 0h 43-3 9

Hopi x Oh 43-4 25 +* x 14 +
Hopi x Oh 43—5 19 +* x 17 +
Hopi x on 43-6 14

Hopi x Oh 43—7 22 4...

Hopi x 0h 43—8 22 +*

Hopi x Oh 43-9 17 +

Hopi x Oh 43-10 21 +*

Hopi x 0h 43-11 21 +* x 18 +4.
Hopi x on 43-12 18 +*

Hopi x 0h 43-13 22 +* x 15 +
Hopi x Oh 43-14 16 +

Hopi x 0h 43—15 18 +*

Hopi x Oh 43—16 21 +* x 20 +*
Hopi x 0h 43—17 20 +* x 9 +
Hopi x 0h 43-18 20 +4

Hopi x Oh 43-19 8

Hopi x 0h 43-20 17 +

Hopi x on 43-21 21 +‘ x 12 +
Hopi x Oh 43-22 13

Hopi x Oh 43-23 20 +* x 12 +
Hopi x 0h 43-24 22 4MI x 14 +
Hopi x Oh 43-25 20 +* x 12 +
Oh 43 parent 9 5
ngi parent 23 22
Test Mean 18 14
Std. Dev. 2.08 1.69

 

(+) Designates significantly better than Oh 43. (*) Designates not
significantly lower than Hopi. Selection and 1987 retesting based on

agronomic type and energence.

18

Table 2. ANOVA: 1986 Emergence Data.

 

SOURCE OF SS 1M5 F
replications 2 21 . 51 10 . 76 2 . 48
entries 26 1459.8 56.15 12.9"“I p<.01
error 52 225.83 4.34
total 80 1707.4

LSD(.01)=4.544
Eleven entries selected for 1987 retesting were significantly better

than Oh 43, and not significantly lower than Hopi.

Table 3. ANOVA: 1987 Energence Data.

 

SOURCE DF SS MS F
replications 2 1.44 .72 .25
entries 12 739.9 61.66 21.56** p<.01
error 24 68.6 2.86

total 38 809.9

19

Table 4. 1987 Emergence Experiment Means Comparisons and Ranking.

1) Hopi a

2) Hopi x Oh 43-16 a b

3) Hopix0h43-11 abc

4) HopixOh43—5 bcd

5) Hopi x Oh 43-13 c d e

6) HopixOh43-4 def
7)HOpix0h43-24 defg

8) HopixOh43-21 efgh

9) HopixOh43-23 efghi

no) Hopi x Oh 43-25 n g h i j
11)Hopix0h43-1 fghijk
12) HopixOh43-17 hijk
.131 0h 43 l

 

All possible pairwise comparisons of means with LSD (.01)=3.88. Any two

means followed by the same letter are nnot significantly different.

20

Table 5. Yield Trial Data for Specific Hybrids (SCA) .

SEL SDLERLFNLNOTNOTNOTEST
HYBRID INDEXYLD WY/M VIGS‘I'DSTDDRPSTLRTLRM

A632HT X #25 117 129+ 91 141 99 96 102 100 114 100 97
A632H'1‘ x #16 115 105 80- 132 99 108 103 100 130+ 100 93
LB 146 x #17 106 114 93 123 99 100 103 100 111 100 97
LH 74 x #16 103 104 91 114 99 93 98 100 117 100 97
LB 74 x #4 107 103 94 109 117 105 103 100 129+ 100 97
8731-1'1‘ x #23 108 117 128+ 92 117 94 100 100 140+ 100 107
Dekalb 524 116 130+ 103 126 135 93 96 100 120 100 100
Dekalb 464 99 107 89- 121 117 100 102 100 103 100 96
Pioneer 3475 126 133+ 112+ 119 126 97 100 100 144+ 100 103
Dekalb 547 110 114 109 105 81 104 103 99- 135+ 100 102
Dekalb T1100 107 138+ 140+ 98 108 95 101 100 123 100 111

Dakalb T1000 80 77- 106 73 63- 90- 95 100 116 100 101

 

Dekalb 572 90 104 125+ 83 45- 88- 93- 99- 121 100 106
Delalb 434 78 so 1;; 79 81 107 L03 99- 107 100 99
Test mean 89 61bu 20% 100 5.6 49 47 100 6596 100 99
Check mean 100 65bu. 21% ion 5.1 48 46 100 79953100 101

 

Hybrid data is expressed in percent of test mean. Selection index is
based on check mean. Estimated relative maturity and test and check
means are in units of measurement. Economic weights are 1.00 for yield,
-2.00 for moisture, and .80 each for stalk and root lodging and ear
droppage resistance. Plus or minus indicates significantly different

from test mean with LSD (.10).

21

not root lodge, and estimated relative maturity. Analysis of variannce
for yield showed significant entry differences (F 41/35=1.85, p<.05) .
The coefficient of variationn was 17.86096. A broad sense heritability of
0.459 was calculated for yield. ANOVA for other traits slnowed highly
significant differences for percent moisture (F 41/36=5.15, p<.01);
highly significant differences for early stand (F 41/41=2.59, p<.01);
and significant differences for resistannce to stalk lodging (P 41/41
=1.77,p<.05) . Coefficient of variation for early stand was 7.136%, and
a broad sense heritability of 0.613 was calculated. Early stand is of
interest because of its relationship to emergence capacity. The yield
test was nnot deep planted, but the capacity to produce long mesocotyls
may correlate positively with seedling emergence force and produce
better stands at normal planting depths (Troyer, 1964) . However,
significantly better emergence was not shown for any test crosses.

Fran yield trial data and tho years' results of energence testing,
further selection on a family basis is possible. Family 16, for
exanrple, was not statistically different fron the Hopi parent in both
years' energence experiments, was of good agrononic plant type, and its
selection index was fourth best when croesed with A632HT. It showed
good early stand data and statistically significant better resistannce to
stalk lodging. Family 25 was the highest yielding of the test crosses
(with A632HT) , and had the second highest selection index overall for a
specific hybrid conbination. Families (lines) #4, #17, and #23 also
merited further selection.

Selection indexes for General Combining Ablity for all the test

lines are presented in Table 6. General Combining Abilities for lines

22

#16, #25, and #17 were the highest. Lines with good GCA are enqnected to
do well in specific hybrid conbinations. The 1987 S2 plant selections
fron these families will be advanced to $3 developnent in 1988.
Populations for recurrent selection my be formed with these selected S2

families. Crosses of sons 82 linnes with other Corn Belt inbred lines

were made to form source populations for future breeding.

Table 6. Inbred Line Evauation Index (GOA).

LINE SELECTION INDEX
Hopi x 0h 43-1 100
Hopi x on 43-4 97
Hopi x 0h 43-5 101
Hopi x Oh 43-11 106
Hopi x on 43-13 so
Hopi x Oh 43-16 109
Hopi x 0h 43-17 123
Hopi x 0h 43-21 95
Hopi x 0h 43-23 97
Hopi x 0h 43-24 34
app; x on 43-25 123

 

GCA selection indexes are the average of the selection indexes for each
inbred in each of its hybrid combinations based on the test means rather
than the checkmeans (as with SCA). Econonnic weights usedwere the same

as those for SCA.

DISCUSSION

Various approaches may prove useful to integrate exotic nraterial
into Corn Belt breeding programs. The method presented here had the
advanntage of concentrating selection for adaptation annd potentially
improved agrononic value in one operation that produced encouraging
results quickly and efficiently.

Yield testing of S4 lines at more locations will be possible with
adequate seed amounts available at that stage. Deep planted yield
trials should be conducted.

Hybrids emerging well from deep planting (3—3.5 inch depths), would
provide several beneficial options to the farmer. With a dry seedbed at
planting time, these hybrids would allow the farmer to adjust planting
depth downward to reach available soil moisture. They might prove
useful for no-till on coarse textured soils with low water-holding
capacity or with sons minimum tillage planting practices and conditions.
Chisel plowing leaves plant residues on the soil surface that can
interfere with good seed placement. Stands are often reduced because
sonneoftheseedisplacedintheseresidues ratherthaninthesoil.
Deeper planting would put the seed through the plant residues into the
soil with more available nnnoisture to ensure better stands. Long
mesocotyl hybrids should be evaluated in no-till, minimum tillage, and
conventional tillage yield trials.

Another apparent drought (and temperature) resisting adaptation of
Hopi Maize is profuse pollen shedding under extremely hot and dry
conditions at time of flowering. This plant characteristic was not a

subject of investigation in this research, but it was apparent from

23

24

observations of the material in the field. The profuse pollen shedding
was seen in several of the Hopi x Oh 43 families in 1987. The Oh 43
type parent is a poor pollen shedder. It did not pollinate effectively
in the Mason, Michigan Dekalb nursery. The 1987 growing season was
unusually hot and dry both at planting and flowering.

The 1986 season was almost the reverse. Moisture was over-abundant
at planting, and again at harvest, with no nnnoisture stress during the
growingseason. Thesetwoextrennesnnayaccount forsoneof the
variation in the two emergence tests. Only two families showed
emergence not significantly lower than the Hopi parent in 1987, while
all 11 selected families were not significantly lower than Hopi in 1986.
TheS2 linesinthe1987 emergenceenqnerimennthadbeeninbredasecond
generation. There nay lnave been nnore segregation for poorer emergence,
and sane loss of vigor associated with emergence. The numbers of plants
emerged in 1987 were substantially less for almost all entries except
tl'e Hopi parent. All 11 families were still significantly better
energing than on 43.

The four inch planting depth appears to lnave served as sufficient
selection pressure to identify some families with enhanced emergence
capacity. Plants were dug from tie 1987 emergence experiment to observe
first internode growth. Plants that emerged appeared to do so nnainly
because their first internode elongated sufficiently. tvbst of the
plants that did not emerge had insufficient first internnode growth to
bring the coleoptile node close enough to the soil surface. Figure 1
shows a Hopi plant in the emergence experiment. The first internode has

elongated about 4 inches (10 cm.) with emergence by the coleoptile.

25

Actual planting depth for the experiment was closer to 5 inches. A four
inch hole was dug, but when covering the seed, an additional inch of
topsoil was placed over the hole. This is seen in Figure 1 where the
coleoptile node is 4 inches fron the seed, and the coleoptile shows
about one inch of additional underground growth. Figure 2 shows a plant
fronn Hopi x on 43—16 32 line. This plannt also emerged with 10 cm. of
first internode growth and about 1 inch (2.54 on.) of coleoptile growth.
Figure 3 shows seedlings of tie 0h 43 parent in the experiment with
first internnode lengtt's and/or seedling energence force insufficient for
emergence.

When selecting offspring from an exotic by adapted cross there is a
tedency toward recovering the adapted parent type. In this research an
effort was made to select for good agronomic types as well as Oh 43
types. Oh 43 types with improved emergence (and improved pollen shed)
made up about half of the plants selected in 1986. Another recurring
good plant type was taller than 0h 43 with a longer and thinner ear with
thinner and deeper kernels. A third selected type was similar to Oh 43
but larger with an intense crerry/purple tassel that shed pollen
profusely. This plant type had red cobs with dark orange colored
kernels. It was the predominant plant type in one of the best families
selected for advancement (family #16) . Plant naturities fell into three
najor classes: an early group which included nnnostly good Oh 43 types, a
middle group with more varieties in plant type, and a late group which
included nany Oh 43 types. Approxinnate relative naturities ranged from
95-110 days. Progeny of selected plants nnaintained good agronomic

characteristics. There was no apparent negative linkage of improved

26

 

Figure 1. First Inter-node Elegation of Hopi Parent.

27

 

Figure 2. First Internode Developnnent of Hopi x 0h 43—16 Line.

 

Figure 3. Failure of Emergence for Oh 43 Parent Seedlings.

29

emergence with agronomic traits.

Even if nno elite lines are derived directly fronnn this adapted by
exotic cross, the best lines for conbining ability might prove useful
when intercrossed to form populations for future recurrent selection
while maintaining the deep planting selection pressure. Lines could be
extracted after each cycle and evaluated in hybrid combinations. While
pronising, it is too early to predict if this program will result in
derivation of elite breeding lines. This breeding program has taken a
modest step toard increasing germplasm diversification with
incorporation of naize from native southwest Americans into a Corn Belt

breeding program.

Hopi Maize emerges fron planting depths over ten inches by its
innherent capacity to produce long first internodes. To improve the
energence of an elite 0h 43 type inbred line crosses were made with Hopi
Maize. Bulked seed was planted to form a population of 250 plannts.
After two generations of sib—nnatirg, 100 plants with good agrononic type
were self pollinated. 'nwenty five selected ears were shelled and
planted ear to row for 1986 $1 populations for inbred line development
using the Pedigree Selection Method. At the sane time, together with
tie Hopi and 0h 43 parents tlney served as 27 entries in a randomized
complete block design experiment to compare emergence capacities.

Eleven of tlne 25 Si families were selected for agronomic type and
emergence significantly better than tl'e Oh 43 and nnot significantly
lower than the Hopi parent. The best plants within those families were
selected for advanncement. Test crosses were made to plants in tle 11
families for a 1987 yield trial. Bulked $2 seed of the 11 families and
the parents formed 13 entries in a 1987 emergence experiment.

Based on yield trial data and two years' energence data, further
selection on a family basis was possible. Six families showed merit
warranting further selection. The 1987 S2 plant selections fron these
families will be advanced to an 83 selection nursery. Sane of these S2
families nay be intercrossed to form populations for recurrent
selection.

Tre breeding method used appeared effective for concentrating
selection for adaptation and improved agronomic value in one operation.
All research was conducted at a commercial maize breeding station. Only
minor nnnodifications of standard procedures were necessary.

30

LIST OF REFERENCES

LIST OF REFERENCES

Benson, G.O. and Reetz, H.F. Corn plant growth from seed to seedling.
National Corn Handbook-3, 1985.

Brom, W.L., Anderson, E.G., and Tuchwena, R. Observations on three
varieties of Hopi Maize. American Journal of Botanny 39:597—607,
1952.

Brown, W. L. and Goodman, M.M. Races of Corn. In G.F. Sprague (Fd.),
Corn and Corn _Imprwenent, American Society of Agrornomy, 1977.

Carter, G.F. and Anderson, E. A Preliminary survey of maize in the
soutmestern U.S. Missouri Botanical Garden Annals 32:297-322,
1945.

Clothier, R.W. The dry farm crops for tie Sulfur Springs Valley. Arizona
Ag. Exp. Station Bulletin 70, 1913.

Coe, E.H. and Neuffer, M.G. The Geeties of Com. In G.F. Sprague

(Fd.), ggrn and Corn Wt, American Society of Agronomy,
1977.

Collins, G.N. A drought resisting adaptation in seedlings of Hopi
vaize. Journal of Ag. Research 1:293-303, 1914.

Day, A.D. Registration of Arizoa Arid Environment baize Germplasm.
Crop Science 26:390, 1986.

Day, A.D., Grove, D.R., and Thompson, R.K. Arizona Indian corn. Ariz.
Acad. of Science 7(1): 8-11, 1972.

Galinat,W.C. and Campbell, R.G. The diffusion of 8 rowed naize from the
southwest to the central plains. Mass. Ag. Exp. Station, 1967.

Goodman, M.M. Estimates of genetic variance in adapted and exotic
populations of nnaize. Crop Science 5:87—90, 1965.

Hallauer, A.R. and Sears, J .H. Integrating exotic germplasnnn into Corn
Belt maize breeding program. Crop Science, vol. 12, 1972.

Inge, F.D. and Loonis, W.E. Growth of the first internode in naize
seedlings. American Journal of Botany 24:542-547, 1937.

31

32

Jenkins, M.T. The segregation of genes affecting yield of grain in
nnaize. Journal of Annerican Society of Agronomy 32:55-63, 1940.

Kiesselbach, T.A. The structure and reproduction of corn. Research
Bulletin 161, Lincoln, Nebraska, 1949.

Mangelsdorf, P.C. and Reeves, R.G. The origin of Indiann corn and its
relatives. Teas Agric. Exp. Stnn. Bulletin 574:1—315, 1939.

Moll, R.H., Salhuana, W.S., and Robinson, H.F. Heterosis and genetic
diversity in variety crosses of nnaize. Crop Science 2:197—198,
1962.

Sprague, G.F. Early testing of inbred lines of corn. Agron. Journal
38:108—117, 1946.

Sprague, G.F. and Miller, P.A. Influence of visual selection during
inbreeding on combining ability in corn. Agronomy Journal 44:
258—262, 1952.

Steel, R.G. and Torrie, J .H. Principles and Procedgrfies of Statistics.
McGraw—Hill. 1980.

Troyer, A.F. The interitance of log first internode in com. Ph.D.
Thesis. U. of Minnesota, 1964.

Wallace, H.A. and Brownn, W.L. Corn andfiits Early Fat_l'ers. Michigan
State University, 1956.

Wellhausen, E.J. Exotic germplasm for improvement of Corn Belt naize.
Annual Hybrid Corn Industry Res. Conf. Proc. 20:31-45, 1965.

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