SOME ASPECTS OF THE GENETIC-ANALYSIS OF DROUGHT TOLERANCE IN WHEAT (TRITICUM-AESTIVUM L)

Six different bread wheat cultivars were used in a drought-stressed ex periment, to estimate genetic variation and heritability for seven mor phological characters related to drought. Path-analysis was used to pa rtition the phenotypic correlations between some of the characters int o direct and indirect effects. The phenotypic stability of the cultiva rs was estimated. Moderate genetic variation was displayed by the root system. The heritability estimates ranged from 0.30 to 0.94. The expe cted genetic advance with selection of the highest 5% was around 0.90 for the root system. The root system had a high positive significant c orrelation with total biomass, and showed the highest direct effect. S hoot heigth had a high negative significant correlation with total bio mass, but exhibited the least direct effect. A significant difference was found between the root length and root-shoot ratio of Plainsman co mpared with those of other cultivars. All cultivars had average stabil ity and general adaptation. However, due to its better root system, hi gher yield and shorter shoot height (plant height) Plainsman is the mo st suitable for drought tolerance breeding.