Genetic variability and trait association analysis in linseed (Linum usitatissimum L.) for yield and related traits

Diversity information mining about a crop for different attributes is an essential step for effective breeding programs. The present investigation evaluates the quantum of genetic variability and determines the relationship among the important agro-economic traits based on two years of phenotypic data of 210 accessions of linseed. The traits, capsule weight per plant, capsule per plant, husk weight per plant, and seed weight per plant exhibited comparatively higher genetic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV). In contrast, oil content and seed per capsule exhibited a lower value. The high magnitude of broad sense heritability was observed for all traits except seeds per capsule and husk weight per plant. The trait, capsules per plant, plant height, and days to 50% flowering showed high genetic advance coupled with high heritability. Hierarchical cluster analysis grouped 210 accessions into six distinct clusters. Out of 210, 144 (68.57%) accessions were grouped into three clusters (I, II, and III), in which cluster-III was the largest, containing 64 accessions followed by cluster II and cluster-I. The highest inter-cluster distance was observed between clusters-I and V (127.85), while the lowest was between clusters-II and IV (27.09). The positive correlation of capsule weight per plant with the seed weight per plant and a negative correlation with the days to 50% flowering indicates that high yielding linseed varieties with early flowering/maturity could be developed through direct and indirect selection. Further, seed yield and oil content could be enhanced together as indicated by ghe positive association among these two important traits. In this study, high yielding accessions with moderate to high oil content such as GP36, GP31, GP14, GP54, GP26, GP24, GP34, GP21, GP37 and GP27 and early flowering (less than 70 days) accessions such as GP2, GP26, GP27, CG33, CG44, CG42, CG132, and CG31 identified as potential genetic materials that could be exploited for developing early maturing varieties with high yield. In addition, information's on various genetic parameters will help breeders to devise suitable breeding methodology for linseed genetic improvement for targeted traits.