Genetic Divergence Studies in Sunflower [Helianthus annuus (L.)]

Forty genotypes of sunflower [Helianthus annuus (L.)] were evaluated during summer 2011 for seed yield and its component. The data were subjected to D² analysis (Mahalanobis, 1936) and grouped into different clusters following Tocher's method. The forty genotypes were grouped in to 5 clusters. The averages intra cluster D² values ranged from 0.00 to 11.16. The clustering pattern of genotypes was independent of their geographical distribution. The strains of cluster III had higher means for days to maturity, head diameter, number of seeds per capitula, number of filled seeds per capitula, seed yield per plant and 100 seed weight. On the other hand, genotypes included in cluster IV had higher mean value for number of unfilled seeds per capitula. On the basis of inter cluster distances, cluster III was found to be more divergent from cluster IV. Taking into account cluster mean for important seed yield components, the various clusters which can provide the desired parents like GMU-1033, GMU-411 for hybridization for improvement of characters.