|ZHANG, FAN - Chinese Academy Of Agricultural Sciences|
|KANG, JUNMEI - Chinese Academy Of Agricultural Sciences|
|LONG, RUI-CAI - Chinese Academy Of Agricultural Sciences|
|SUN, YAN - China Agricultural University|
|WANG, ZHEN - Chinese Academy Of Agricultural Sciences|
|ZHAO, ZHONGXIANG - Cangzhou Technical College|
|ZHANG, TIEJUN - Chinese Academy Of Agricultural Sciences|
|YANG, QINGCHUAN - Chinese Academy Of Agricultural Sciences|
Submitted to: The Plant Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/13/2020
Publication Date: 10/22/2020
Citation: Zhang, F., Kang, J., Long, R., Yu, L., Sun, Y., Wang, Z., Zhao, Z., Zhang, T., Yang, Q. 2020. Construction of high-density genetic linkage map and mapping quantitative trait loci (QTL) for flowering time in autotetraploid alfalfa (Medicago sativa L.) using genotyping by sequencing. The Plant Genome. 13(3). Article e20045. https://doi.org/10.1002/tpg2.20045.
Interpretive Summary: Alfalfa (Medicago sativa L.) is an important legume forage grown worldwide. Alfalfa is called “Queen of Forage” due to its high production and nutrition values. The present study reports the identification of genetic loci associated with flowering time in a biparental population of alfalfa. Identifying quantitative trait loci associated with flowering time helps to understand the genetic base to regulate flowering time in alfalfa. With further validation, these markers linked closely to the identified QTLs can be used for marker-assisted selection (MAS) in breeding programs to improved alfalfa yield and quality by regulating flowering time.
Technical Abstract: Flowering time is an important agronomic trait of alfalfa (Medicago sativa L.). Managing flowering time can produce economic benefits for farmers. To understand the genetic basis of this trait, quantitative trait loci (QTL) mapping was conducted in a full-sib population that consisted of 392 individuals segregated based on flowering time. High density linkage maps were constructed using single nucleotide polymorphism (SNP) markers generated by genotyping-by-sequencing (GBS). The linkage maps contained 3,818 SNP markers on 64 linkage groups in two parents. The average marker density was 4.33 cM for Parent 1 (P1) and 1.47 cM for Parent 2 (P2). Phenotypic data for flowering time was collected for three years at one location. Twenty-eight QTLs were identified associated with flowering time. Eleven QTLs explained more than 10% of the phenotypic variation. Among them, five main effect QTLs located on linkage group (LG) 7D of P1 and five main effect QTLs located on LG 6D of P2 were identified. Three QTLs were co-located with other QTLs. The identified linked markers to QTLs could be used for marker-assisted selection in breeding programs to develop new alfalfa varieties to modulate flowering time.