EXPRESSION. OF HYBRID VIGOUR AND DOMINANCE IN INTERVARIETAL CROSSES OF COTTON

Level of hybrid vigour and dominance estimates for six quantitative and qualitative parameters were examined in intervarietal crosses of nine cultivars of cotton. Results demonstrated that the parents and their F 1 hybrids differed significantly (P < 0.01) for all the traits studied indicating manifestation of heterosis for all the traits in at least one or more crosses. Highest average heterosis (32.41%), heterobeltiosis (16.37%) and dominance estimates (4.93) were found for number of bolls per plant. The extent of heterotic effects was appreciably influenced by the hybrid genotype, the direction of cross and the trait concerned. The cross Qalandri x Allepo-I may be selected as the superior hybrid combination which could be exploited in cotton breeding programme for developing new high yielding cotton varieties for commercial production.