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ARS Home » Pacific West Area » Pullman, Washington » Plant Germplasm Introduction and Testing Research » Research » Publications at this Location » Publication #401685
Research Project: Enhancing Resistance to Biotic and Abiotic Stresses in Alfalfa

Location: Plant Germplasm Introduction and Testing Research

Title: Identification of QTL and candidate genes associated with biomass yield and feed quality in response to water deficit in alfalfa (Medicago sativa L.) using linkage mapping and RNA-Seq

Author
item JIANG, XUEQIAN - Chinese Academy Of Agricultural Sciences
item YU, ANDONG - Chinese Academy Of Agricultural Sciences
item ZHANG, FAN - Chinese Academy Of Agricultural Sciences
item YANG, TIANHUI - Chinese Academy Of Agricultural Sciences
item WANG, CHUAN - Chinese Academy Of Agricultural Sciences
item GAO, TING - Chinese Academy Of Agricultural Sciences
item YANG, QINGCHUAN - Chinese Academy Of Agricultural Sciences
item Yu, Long-Xi
item WANG, ZHEN - Chinese Academy Of Agricultural Sciences
item KANG, JUNMEI - Chinese Academy Of Agricultural Sciences

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/26/2022
Publication Date: 10/17/2022
Citation: Jiang, X., Yu, A., Zhang, F., Yang, T., Wang, C., Gao, T., Yang, Q., Yu, L., Wang, Z., Kang, J. 2022. Identification of QTL and candidate genes associated with biomass yield and feed quality in response to water deficit in alfalfa (Medicago sativa L.) using linkage mapping and RNA-Seq. Frontiers in Plant Science. 13. Article 996672. https://doi.org/10.3389/fpls.2022.996672.
DOI: https://doi.org/10.3389/fpls.2022.996672

Interpretive Summary: Drought stress is one of the main limiting factors affecting alfalfa production worldwide. However, the genetic and especially the molecular mechanisms for drought tolerance in alfalfa are poorly understood. In this study, we mapped quantitative trait loci (QTLs) in an F1 population by combining 12 phenotypic data (biomass yield, plant height, and 10 feed quality-related traits). A total of 48 significant QTLs were identified. Among them, nine main QTLs, which explained more than 10% phenotypic variance, were detected for biomass yield, plant height, CP, ASH, P, K, and Mg. A total of 31 candidate genes were identified in the nine main QTL intervals based on the RNA sequence analysis under the drought condition. Among them, 22 functional proteins were finally identified. The results of the present study will be useful for improving drought tolerance of alfalfa varieties by marker-assisted selection (MAS).

Technical Abstract: Biomass yield and feed quality are the most important traits in alfalfa (Medicago sativa L.), which directly affect its economic value. Drought stress is one of the main limiting factors affecting alfalfa production worldwide. However, the genetic and especially the molecular mechanisms for drought tolerance in alfalfa are poorly understood. In this study, linkage mapping was performed in an F1 population by combining 12 phenotypic data (biomass yield, plant height, and 10 feed quality-related traits). A total of 48 significant QTLs were identified on the high-density genetic linkage maps that were constructed in our previous study. Among them, nine main QTLs, which explained more than 10% phenotypic variance, were detected for biomass yield, plant height, CP, ASH, P, K, and Mg. A total of 31 candidate genes were identified in the nine main QTL intervals based on the RNA-seq analysis under the drought condition. Blast-P was further performed to screen candidate genes controlling drought tolerance, and 22 functional protein candidates were finally identified. The results of the present study will be useful for improving drought tolerance of alfalfa varieties by marker-assisted selection (MAS), and provide promising candidates for further gene cloning and mechanism study.