Exploring the Genetic Foundations of Salt Tolerance in Common Vetch (Vicia sativa L.) via Genome-Wide Association Analysis

TL;DR

This study identifies genetic loci and genes linked to salt tolerance in common vetch, offering tools for breeding more resilient crops.

Contribution

The study discovers 20 novel loci and 7 candidate genes associated with salt tolerance in common vetch.

Findings

20 loci were identified, explaining 9.7–21.8% of phenotypic variation in salt tolerance traits.

13 loci showed pleiotropic effects on multiple salt tolerance-related traits.

Seven candidate genes were found to encode regulatory proteins involved in salt tolerance.

Abstract

Background/Objectives: Common vetch (Vicia sativa L.) is a globally cultivated leguminous crop, valued for its high nutritional content and role in sustainable agriculture. Methods: To identify loci or genes significantly associated with salt tolerance, we conducted a genome-wide association study (GWAS) using 172 common vetch accessions primarily from diverse geographic regions. Single-nucleotide polymorphisms (SNPs) were obtained through re-sequencing, and five salt tolerance-related traits, including the germination rate (GR), germination potential (GP), germination index (GI), shoot length (SL), and root length (RL), were evaluated under salt stress conditions. We have identified 20 loci significantly associated with salt tolerance-related traits, and explaining 9.7–21.8% of the phenotypic variation. Notably, 13 loci exhibited pleiotropic effects on multiple traits; include qST1.1 (associated with SL, GR, GI), qST1.3 (RL, SL, GP), qST2.5 (SL, GR, GI, GP), and qST2.7 (SL, RL, GP, GI), and should be prioritized in future breeding programs. All 20 loci are novel compared to previous reports. Furthermore, we identified 7 candidate genes encoding key regulatory proteins, including a zinc finger MYM-type protein, ubiquitin-like domain-containing protein, transcription factor bHLH, ethylene-responsive transcription factor, auxin-responsive protein, and serine/threonine-protein kinase, as potential regulators of salt tolerance. Conclusions: This study advances our understanding of the genetic basis of salt tolerance in common vetch and provides valuable loci, molecular tools, and elite accessions. HZMC1352, GLF303, GLF301, HZMC1387, GLF306, GLF368, GLF342, HZMC1384, HZMC1355, GLF307, HZMC1366 are used for improving salt tolerance in breeding programs.

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