Genetic mapping of leaf-related traits in autotetraploid alfalfa (Medicago sativa L.)

Abstract

Abstract Understanding the genetic architecture of leaf-related traits is important for improving alfalfa yield. Leaf size has a great influence on the protein content and yield for alfalfa. In this study, a low-yielding precocious alfalfa individual (paternal parent) and a high-yielding late-maturing alfalfa individual (maternal parent) were used to build a hybrid F1 population of 149 individuals. The linkage map was constructed using simple sequence repeat and single nucleotide polymorphism markers, and quantitative trait loci (QTL) for leaf length, leaf width, and leaf area were mapped using 3 years phenotypic data. We identified a total of 60 QTLs associated with leaf size. These QTLs were located on chromosomes 1 to 8, and the percent of phenotypic variation explained by QTL ranged from 2.97% to 18.78%. There were 13 QTLs explain more than 10% of phenotypic variation, most of which represent novel loci controlling leaf traits that have not been found in previous studies. The nearest markers of QTL may be used in marker-assisted selection and breeding alfalfa new varieties with high yield.