Genetic Diversity Assessment of some Flax Genotypes Using Morphological and Molecular Markers

Abstract

Twelve flax genotypes (10 promising strains and two control varieties) were evaluated for straw, seed, technological characteristics, and genetic diversity using morphological and molecular characters, which will assist breeders in evaluating genetic diversity and relationships among the different flax genotypes at Giza Exp. Station, Field crops Res. Inst., Agricultural Research Center (A. R. C.), Egypt during two consecutive seasons 2018/2019 and 2019/2020, The design of experimental was a randomized complete block arrangement with three replications. The results showed that the new promising Strain 620/3/5 had the highest estimates in total plant height, technical stem length, straw yield/plant as well as per hectare, fiber yield per hectare, and fiber length in both seasons, while S.651 had the highest total fiber percentage. S.889/50/5/9 obtained the highest values in terms of number of seeds per capsule, seed yield/plant as well as per hectare, oil yield per hectare, and oil percentage in both seasons, but only in terms of number of capsules / plant and seed index in the second season. For genetic diversity, sixteen molecular markers were used (8 ISSR and 8 SCOT primers). ISSR contains more polymorphic information content (PIC) than SCOT. The PIC for ISSR primers ranged from 0.37 to 0.57, with an average of 0.49, and the PIC for SCOT ranged from 0.19 to 0.52, with an average of 0.39.  PIC, Marker index (MI), heterozygosity (H), effective multiplex ratio (E), discriminating power (D), resolving power (R), and havp (arithmetic mean heterozygosity) for ISSR higher than SCOT Both markers showed promising sources of variation, assisting breeders in assessing the genetic diversity and interactions between the various flax genotypes. Total DNA fragments generated for both markers were 106, and an average of 7.0 bands per primer was found. While 58 of the fragments were monomorphic and 48 were polymorphic, ISSR had a greater polymorphism proportion than SCOT, at 59.4% against 39.3%. The dendrogram produced by the UPGMA algorithm effectively distinguished the two clusters of flax genotypes. The genotypes and genetic distances varied between 0.029 to 0.620. The data for straw and seed yield as well as technological characteristics are highlighted in PCA for morphological data.

Full-Text (PDF)