Detection of Quantitative Trait Loci (QTL) associated with the spring regrowth vigor trait in alfalfa (Medicago sativa L.)

Abstract Background: Alfalfa ( Medicago sativa L.) is a perennial forage legume with a reputation as being the “queen of forage”. Spring regrowth vigor refers to the process of perennial alfalfa returning to growth after winter survival. The objective of this research was to identify candidate genes significantly associated with spring regrowth vigor.Results: We used a tetraploid alfalfa F1 population comprised of 392 progenies to identify quantitative trait loci (QTL) that control this trait. The F1 population phenotypic data were collected using a total of three environmental phenotypic data. The mapping population was genotyped using Genotyping-by-sequencing (GBS), and linkage maps were developed based on single nucleotide polymorphism (SNP) markers. Fifteen significant QTL for spring regrowth vigor were detected in both parents. Five QTL were identified in the male genetic map, while ten QTL were identified in the female. Four QTL were located on homolog 7D of the male parent, and two QTL were colocalized. Five QTL were mapped on homolog 6D of the female parent, and two QTL were colocalized.Conclusions: The QTL presented in this study can be used to improve the efficiency of alfalfa breeding programs and provide valuable resources for the genetic improvement of alfalfa using marker-assisted selection (MAS).β These authors contributed equally to this research. *Correspondence:Junmei Kangkangjunmei@caas.cn