Assessment of genetic diversity among linseed (Linum usitatissimum L.) germplasm based on morphological traits

Abstract

Variability and genetic diversity assessment is foremost activity to be embarked before any crop improvement programme. Divergence analysis is helpful in identifying suitable and diverse parents for realizing high heterotic effects with transgressive segregants in later generations. Thus, a field experiment was conducted using 30 genotypes of linseed germplasm in randomized block design with three replications during rabi 2018-19 to assess the extent of genetic diversity. As per the results obtained, cluster analysis grouped whole germplasm into VI clusters. Cluster II was the largest with 10 linseed accessions and cluster I was smallest with single accession. The inter-cluster distance was the farthest between cluster I and cluster VI (D2=7.143) followed by cluster I and III (D2=7.134) depicting greater genetic divergence among clusters. The intra-cluster distance ranged from 2.066 in cluster II to 2.776 in cluster IV. The contribution of days to maturity (11.08%), technical height (10.63%) and seeds per capsule (9.66%) towards genetic divergence were higher. During PCA analysis, seven principal components (PC1 to PC7) had eigen values greater than one and accounted for 99.70% of the total variance while the first principal component (PC1) alone explained about 50.30% of the entire variability. The major contributing characters from the first PC, were days to 50% flowering, plant height, technical height, primary and secondary branches per plant, capsules per plant along with aerial biomass and seed yield per plant.