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

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 (one), plant height (one), CP (two), ASH (one), P (two), K(one), and Mg (one). 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.

Partial root-zone drying subsurface drip irrigation increased the alfalfa quality yield but decreased the alfalfa quality content

“…It is imperative to establish a proper framework for the irrigation techniques tailored to specific crops and purposes, whether the crop is grown for forage, grains, or fiber ( Chen et al., 2020 ). It is very necessary to manage properly the irrigation water for crop production and forage quality ( Jiang et al., 2022 ; Xu et al., 2022 ). Developing proper water use strategy for the vegetation and forage production, especially under the deficit irrigation ( Li et al., 2018 ; El Mouttaqi et al., 2023 ), is essential to improve the forage quality and ensure sustainable vegetation production ( Fu et al., 2022 ).…”