Mapping freezing tolerance QTL in alfalfa: based on indoor phenotyping.

Abstract

Abstract Background Winter freezing temperature impacts alfalfa ( Medicago sativa L.) persistence and seasonal yield and can lead to the death of the plant. Understanding the genetic mechanisms of alfalfa freezing tolerance (FT) using high-throughput phenotyping and genotyping is crucial to select suitable germplasm and develop winter-hardy cultivars. Several clones of an alfalfa F 1 mapping population (3010 x CW 1010) were tested for FT using a cold chamber. The population was genotyped with SNP markers identified using genotyping-by-sequencing (GBS) and the quantitative trait loci (QTL) associated with FT were mapped on the parent-specific linkage maps. The ultimate goal is to develop non-dormant and winter-hardy alfalfa cultivars that can produce extended growth in the areas where winters are often mild. Results Alfalfa FT screening method optimized in this experiment comprises three major steps: clone preparation, acclimation, and freezing test. Twenty clones of each genotype were tested, where 10 samples were treated with freezing temperature, and 10 were used as controls. A moderate positive correlation (r ~ 0.36, P CBF . The BLAST alignment of a CBF sequence of M . truncatula , a close relative of alfalfa, against the alfalfa reference showed that the gene’s ortholog resides around 75 Mb on chromosome 6. Conclusions The indoor freezing tolerance selection method reported is useful for alfalfa breeders to accelerate breeding cycles through indirect selection. The QTL and associated markers add to the genomic resources for the research community and can be used in marker-assisted selection (MAS) for alfalfa cold tolerance improvement.

Plant phenotyping relevance

アルファルファの凍結耐性を測定する屋内スクリーニング法を最適化し、手順と有用性を示しているため、表現型取得法が研究の中心である。

Code and data availability

The paper reports indoor freezing-tolerance phenotyping and QTL mapping in alfalfa, but no public phenotype dataset, images, analysis code, or trained models are deposited. The only data availability statements concern GBS raw reads (SRA SRP150116, a molecular omics deposit) and a GBS barcode key file on Dryad — both p

No evidence-backed public reproduction asset is currently recorded.