Drought is one of the most important abiotic plant stresses that negatively effects yield and quality of crops. Dry bean (Phaseolus vulgaris L.) is an important crop in Michigan and decreased rainfall is affecting productivity of the bean crop which is largely raised under rainfed conditions. Ninety-six dry bean genotypes were grown under drought stress in the field in Michigan in 2011 and 2012. Plants were excavated at flowering to investigate the number of basal roots, basal root angle, taproot diameter, and overall root score. At harvest, biomass was measured and harvest index and yield were calculated. Several root characteristics were identified as contributing to drought stress tolerance and specific genotypes were identified as possessing superior drought tolerant root traits including high basal root numbers in most pinto bean genotypes. The same genotypes were grown in growth pouches and analyzed using WinRhizo root analysis software. Data for basal root whorl number, root length, surface area, average diameter, root volume and root tips were recorded. Basal root whorl number and root length were identified as significant traits and pink beans had the largest number of basal root whorls. The same genotypes were subjected to drought stress under limited root growth in small pots in the growth chamber and rated for wilting, stem greenness and unifoliate senescence after 21 days of stress. Watering was resumed and ratings for survival were taken after a 14 day recovery period. Wilting was identified as an important trait for survival and several genotypes expressed high survival rates. Superior genotypes were identified for both root and shoot traits that could be combined in future breeding activities to enhance the drought tolerance of dry beans.
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