Genetic Variability, Diversity and Identification of Trait-Specific Accessions from the Conserved Sunflower Germplasm for Exploitation in the Breeding Programme

The objective of the study is to characterize, evaluate and classify 2149 sunflower germplasm accessions during 2011-2012 and 2012-2013 for identification of trait-specific accessions. The analysis of variance revealed significant differences among the genotypes for almost all characters which favour the selection. High heritability associated with high genetic advance as per cent of mean (GAM) was recorded for days to maturity, indicating lesser environmental influence and role of additive gene action. Moderate heritability coupled with moderate-to-low GAM was observed for seed yield per plant, head diameter and oil content, suggesting the low existence of non-additive genes. Associations among characters exist especially for head diameter, 100-seed weight and plant height in the improvement in seed yield, whereas seed yield per plant had a negative correlation with oil content. Based on cluster analysis, 416 accessions grouped under cluster IV may be considered as the genotypes with high yielding ability along with high oil content and medium maturity. The first principal component accounted for 29.20% of the total variation in the population with more contribution from oil content, while second PC contributed 57.6% to days to maturity and 50% flowering contributed maximum. DUS characters such as pigmentation of seedlings, leaf petiole, disc and stem can be considered as morphological markers to differentiate the germplasm. Ray floret colouration, plant branching, type of branching and pollen colour characters can help the breeder to identify the specific germplasm. The identified trait-specific accessions will help in effective utilization of promising accessions in the breeding.