Association between molecular diversity and hybrid performance in sunfower (Helianthus annuus L.)

The present study was aimed to assess the molecular genetic diversity in 14 parental lines (10 maintainers and 4 restorers) of sunfower crop using 51 SSR markers. A total of 147 alleles were produced with the range of 1–6 alleles per locus. The polymorphic information content (PIC) values ranged from 0.12(ORS1198 in LG5) to 0.74(ORS384 in LG15) with an average PIC of 0.51. A phylogenetic tree was constructed by neighbour- joining method which grouped the parents into four clusters. Among the maintainer and restorer combinations, the dissimilarity index was maximum between CMS 519B and CSFI 99 (0.67) which indicateed high divergence between them. Lower dissimilarity value was observed between RCR CMS 38B and LTRR 341 (0.40) suggested less divergence between them. Mahalanobis D² analysis was also carried out among the parental lines. The D² analysis grouped the parental lines into six clusters. Among them genotype pairs CMS104B vs RHA 1–1 and CSFI 99 vs LTRR341 had highest and lowest D² values respectively. Dissimilarity and D² values for parental combinations, mean performance, mid and better parental heterosis of 40 hybrids for yield and its component traits were subjected to simple correlation analysis. The D² analysis did not show any association with performance of hybrids. However, the dissimilarity values showed association with hybrid performance and heterosis for plant height and volume weight. Hence, the present study indicated that the selection of parental genotypes with high molecular diversity could result in improved performance of plant height and volume weight in sunfower hybrids. However further study is required with multi environment data sets.