Multivariate analysis among indigenous and exotic advanced inbred lines of sunflower (Helianthus annuus L.) for genetic improvement

Evaluation and validation of 358 Indian-origin and exotic inbred lines of sunflower (Helianthus annuus L.) was done over two years to identify trait-specific inbreds with desirable agronomical features for genetic improvement. The analysis of variance exhibited significant differences among the genotypes for most of the agronomic traits studied, which favor selection. Positive correlations were recorded among the various characters in the improvement of seed yield, particularly for plant height, head diameter, and 100 seed weight. Cluster analysis grouped 163 inbreds under Cluster V, which included genotypes with medium maturity, high oil content and good yielding ability. The clustering pattern indicated the association between geographic diversity and genetic diversity. The first principal component accounted for 75% of the total variation in the population. The most important trait that contributed more to the variation in PC1 was plant height (0.989), followed by the number of leaves per plant (0.113). The second principal component accounted for 87% of the total variation and was positively associated with days to 50% flowering (0.674) and days to maturity (0.654), whereas it was negatively associated with seed yield per plant (-0312). Several trait-specific inbred lines were identified using multivariate analysis that may serve as potential breeding material/parental lines for effective utilization in the heterosis breeding programme for developing agronomically superior heterotic sunflower hybrids.