Analysis of genetic diversity in Indian and exotic linseed germplasm and identification of trait specific superior accessions

Aim : Linseed is a multipurpose crop known for oil, fibre, paper, wax and nutraceuticals. Indian subcontinent is a center of origin and domestication for this crop and therefore it is imperative to study the existing genetic diversity among Indian/exotic germplasm accessions. Methodology : Total 191 accessions of linseed germplasm were evaluated in Augmented Block Design with three check varieties Rashmi, Surabhi, and RLC76 randomized in 7 blocks consisting of 27 accessions each. Descriptive statistics, Principal component analysis (PCA) and Ward's agglomerative hierarchical clustering were done using SAS software. Correlation matrices were generated using R. Results : Wide range of phenotypic expression for important agro-morphological traits was observed in linseed germplasm. PCA identified days to flowering, plant height, thousand seed weight, seed weight and number per boll, seed yield and seed size as the most important traits responsible for variation in the germplasm accessions. Custer analysis grouped the accessions under four major clusters which indicated fair association of genetic diversity and geographica diversity. Few trait specific promising accessions such as IC0096539, IC0096496 (early flowering and maturity), IC0096487, IC0096488 (large boll size), IC0096490 (high oil content and bold seeds), IC0054949, IC0054954 (bold seeds),EC0718827 (tall, large corolla), and EC0718835 (high seed yield/plant) were identified with high estimates of heritability for the mentioned traits. SSR profiling of trait specific accessions was done to develop unique molecular identity. Interpretation : The inter-relationships between the traits suggested that accessions with short flowering and maturity duration, low plant height, large bolls and bold seeds should be given priority in breeding for enhanced yield. Donors for various traits were identified which may be used in future linseed breeding to target yield enhancement and diverse geographical adaptation.