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.

Genetic diversity of SAD and FAD genes responsible for the fatty acid composition in flax cultivars and lines

“…However, most of the discovered polymorphisms were silent. Our data are similar to the results of previous studies, where silent and missense mutations were identified in SAD, FAD2, and FAD3 genes, while stop codons were revealed in FAD3 [10,12,15,16,22]. In the present study, most of the samples with low LIN and high LIO content had both the mutation in CP027631.1:16092348 that resulted in a stop codon in FAD3A and the mutation in CP027622.1:1035655 that resulted in histidine to tyrosine substitution in FAD3B, while all cultivars and lines with high LIN had not these mutations.…”

Development and Complex Application of Methods for the Identification of Mutations in the FAD3A and FAD3B Genes Resulting in the Reduced Content of Linolenic Acid in Flax Oil

“…For the identification of FAD3 mutations that result in a low LIN content in linseed oil, only CAPS markers were previously used [ 26 , 29 , 36 ]. Perhaps, the CAPS analysis was the only method because it is easy-to-use and can be applied in a wide range of laboratories, including those where high-throughput sequencers and real-time PCR systems are unavailable [ 37 , 38 ].…”

“…Perhaps, the CAPS analysis was the only method because it is easy-to-use and can be applied in a wide range of laboratories, including those where high-throughput sequencers and real-time PCR systems are unavailable [ 37 , 38 ]. CAPS markers were designed for the detection of nonsense mutations in FAD3A (exon 5) and FAD3B (exon 1) [ 26 ], nonsense mutation in FAD3A (exon 5) [ 39 ], nonsense mutations in FAD3A (exon 1) and histidine to tyrosine substitution in FAD3B (exon 2) [ 29 ]. However, in the study [ 39 ], authors failed to identify low-LIN varieties using the developed CAPS markers.…”

“…Two nonsense mutations in FAD3A (exons 1 and 5) and a nonsense mutation and histidine to tyrosine substitution in FAD3B (exons 1 and 2 respectively) were revealed in flax varieties with a reduced LIN content [ 28 ]. Nonsense mutation in FAD3A (exon 1) and histidine to tyrosine substitution in FAD3B (exon 2) determined a low LIN content in the study on 40 flax lines [ 29 ]. In our previous studies on 279 flax varieties [ 18 , 30 ], three low-LIN mutations were identified: two nonsense mutations in FAD3A (exons 1 and 5) and histidine to tyrosine substitution in FAD3B (exon 2).…”

Formation of a system of genetic certification of linseed

“…В настоящее время для оптимизации этапов селекционного процесса и повышения эффективности отбора наиболее рациональным считается использование высокоточных и надежных молекулярно-генетических методов [5]. ДНК-идентификация сортов может регулировать защиту авторских прав селекционных учреждений и контролировать чистоту сортов.…”