Polymorphism of genes controlling low level of linolenic acid in lines from VIR flax genetic collection

Abstract

Background. Linseed solin varieties were created for nutrition, but the effect of oil fatty acid (FA) composition on other characters is not clear. Materials and methods. Using 6 inbreeding generations from 26 heterogeneous flax accessions were generated 19 high (HL), 7 medium (ML) and 14 low linolenic (LL) lines. For each lines contents of 5 basic FA: palmitic, stearic, oleic (OLE), linoleic (LIO) and linolenic (LIN); the ratio LIO/LIN, oil iodine number, vegetative period (VP) phases and plants size were evaluated. Development of CAPS marker for LuFAD3A gene was performed using idtdna.com. Sequencing of LIN genes sites was done in the Centre MCT SPBGU and Eurogen. Results. ANOVA showed significant differences HL, ML and LL groups for PAL, OLE, LIO, LIN, LIO/LIN, IOD. Considerable decrease of LIN, causes asymmetric changes in FA ratio and correlations between them and other traits. Factor analysis revealed the influence of two factors. The first one divided lines according to their LIN level and characters associated with it, the second one according to the VP and OLE. LIN synthesis is controlled by two complementary genes LuFAD3A and LuFAD3B. Sequencing of LuFAD3A gene 1 exon of 6 lines revealed a mutation (G255 A255), resulting in formation of stop codon. Developed developed CAPS-marker confirmed the homozygosity of hybrids between LL (gc-391) and HL lines (gc-65, 109, 121). Descendants of hybrid between gc-109 and gc-391 ripened 8-10 days earlier than gc-391. CAPS markers of LuFAD3B gene revealed differences between HL, ML, LL lines. Sequencing of this gene first exon and the beginning of the second one in 3 lines (1HL, 2LL) showed that this method reveals a mutation in the second restriction site, located in the 2 exon (C6 T6), and causing the replacement Hys Tyr. Conclusion. Lines from GC have wide variability of FA and other agronomic characters, combination of which will expand the cultivation of solin.