Exploring Linseed (Linum usitatissimum L.) Germplasm Diversity through Morphological, Biochemical, and Molecular Markers

Abstract

The study focused on the characterization of 18 linseed (Linum usitatissimum L.) germplasms to evaluate genetic diversity through morphological, biochemical, and molecular markers. Germplasm characterization is essential for identifying valuable traits and facilitating the development of effective breeding programs. Significant variation was observed among the eighteen genotypes for agro-morphological traits. Similarity coefficients ranged from 0.00 (indicating complete dissimilarity) to 0.78, with GP-381 – R-4237, GP-208 – R-4253, and others being the most dissimilar. Days to first flowering ranged between 38.5 days (R-4218) and 41.5 days (GP-405), with an average of 39.41 days. GP-208 showed the earliest 50% flowering (51.5 days), while GP-345 was the latest (56.5 days). Capsule production varied from 14 (R-4237) to 23 (GP-208), with a mean of 16.75 per plant. Plant height ranged between 48.16 cm (GP-381) and 72.12 cm (R-4266), with a mean height of 56.71 cm. The number of seeds per capsule ranged from 4.5 (R-4218) to 12 (GP-208), with a mean of 7.22. The 1000 seed weight ranged between 4.72 g (R-4253) and 6.97 g (R-4237, R-4275). Primary branches varied from 3.5 (GP-345) to 11 (R-4244, GP-209), with an average of 6.4. Among the 18 lines, 15 had purple flowers, while GP-433 was off-white, GP-411 had white, and GP-345 had dark purple flowers. Yield ranged from 74.7 g per plant (GP-405) to 143.75 g per plant (GP-208), with an average of 97.09 g per plant. SDS-PAGE revealed 13 protein bands, with eight being polymorphic and five monomorphic. Cluster analysis using UPGMA grouped the genotypes into two major clusters at 50% homology, indicating moderate genetic variation. ISSR markers revealed high diversity in genotypes GP-352, GP-208, and GP-473. Primers UBC-815, UBC-819, and UBC-825 showed high polymorphism and PIC values (0.41 to 0.48). SSR analysis confirmed that GP-473 and GP-208 were the most diverse. Primers LU-3, LU-6, LU-8, and LU-9 had the highest PIC values and 100% polymorphism.