Identification of RAPD Marker Associated with Morphological Traits and Population Structure Assessed in Cultivated Flax (Linum Usitassimum L.)

Linum is the largest genus of the Linaceae family comprising nearly 2030 species. Flax (Linum usitassimum L.) is the third largest natural fiber crop in the world. In the present study, RAPD marker were employed to identify informative markers associated with traits such as plant high, weight of capsules per plant, weight branch, capsules number of branches, capsules of the main stem, stem length, branch length, number of branches, thousand seed weight, number of capsules per plant, seed yield, biological yield and harvest index in flax cultivars. Thirteen RAPD primers amplified 169 loci among 10 flax cultivars, with an average of 13 loci per primer. Polymorphic information content (PIC) ranged from 0.05 (OPA-03) to 0.29 (OPD03), with an average of 0.16. Cluster analysis based on molecular data assigned the genotypes into two groups, which coincided to geographic distribution. Cluster analysis result was confirmed by principal components analysis. Population structure analysis using model-based Bayesian confirmed the K=2, as the reliable value for the number of clusters. Stepwise regression analysis between molecular data as independent variables, and morphological data as dependent variables was performed to identify informative markers associated with the studied traits. Loci OPD-03 and OPD-05 were associated with both thousand seed weight and number of branches. Since all used RAPD loci except OPB-04 showed significant association with the studied traits, therefore, it is possible to use these primers along with morphological traits in flax breeding programs for identification of suitable parents to produce mapping populations and hybrid varieties.