School of Chemistry and Chemical Engineering, North University of China, Taiyuan, 030051, China.
Future Food Beacon, School of Biosciences, University of Nottingham Malaysia, Selangor Darul Ehsan, Jalan Broga, 43500, Semenyih, Malaysia.
BMC Plant Biol. 2023 May 30;23(1):287. doi: 10.1186/s12870-023-04293-w.
Assessment of segregating populations for their ability to withstand drought stress conditions is one of the best approaches to develop breeding lines and drought tolerant varieties. Bambara groundnut (Vigna subterranea L. Verdc.) is a leguminous crop, capable of growing in low-input agricultural systems in semi-arid areas. An F bi-parental segregating population obtained from S19-3 × DodR was developed to evaluate the effect of drought stress on photosynthetic parameters and identify QTLs associated with these traits under drought-stressed and well-watered conditions in a rainout shelter.
Stomatal conductance (gs), photosynthesis rate (A), transpiration rate (E) and intracellular CO (Ci) were significantly reduced (p < 0.05) while water use efficiency (WUE) was significantly increased (p < 0.05) under drought-stressed conditions. A strong linear correlation was observed between gs, WUE, A, E and Ci under both water regimes. The variability between different water treatment, among individual lines and the interaction between lines and environment for photosynthetic parameters provides resources for superior lines selection and drought resistant variety improvement. Significant QTL for gs and F/F under well-watered conditions were mapped on LG5 and LG3, respectively, with more than 20% of the PVE, which could be considered as the major QTL to control these traits. Five clustered QTLs for photosynthetic traits under drought-stressed and well-watered conditions were mapped on LG5, LG6A, LG10 and LG11, respectively.
Significant and putative QTLs associated with photosynthetic parameters and the effect of drought stress on these traits have been revealed by QTL linkage mapping and field experiment in the F segregating population derived from S19-3 × DodR in bambara groundnut. The study provides fundamental knowledge of how photosynthetic traits response to drought stress and how genetic features control these traits under drought-stressed and well-watered conditions in bambara groundnut.
评估种群抵御干旱胁迫的能力是培育品系和耐旱品种的最佳方法之一。斑豆（Vigna subterranea L. Verdc.）是一种豆科作物，能够在半干旱地区的低投入农业系统中生长。通过 S19-3×DodR 获得的 F2 双亲分离群体，旨在评估干旱胁迫对光合参数的影响，并在遮雨棚中干旱胁迫和充分供水条件下鉴定与这些性状相关的 QTL。
在干旱胁迫下，气孔导度（gs）、光合作用率（A）、蒸腾速率（E）和胞间 CO2（Ci）显著降低（p<0.05），而水分利用效率（WUE）显著增加（p<0.05）。在两种水分条件下，gs、WUE、A、E 和 Ci 之间存在很强的线性相关性。不同水分处理、个体间以及水分和环境间的互作对光合参数的变异性为选择优良品系和改良耐旱品种提供了资源。在充分供水条件下，gs 和 F/F 的显著 QTL 分别定位在 LG5 和 LG3 上，超过 20%的 PVE，可视为控制这些性状的主效 QTL。在干旱胁迫和充分供水条件下，与光合性状相关的 5 个聚类 QTL 分别定位在 LG5、LG6A、LG10 和 LG11 上。
通过 QTL 连锁作图和 S19-3×DodR 衍生的 F2 分离群体的田间试验，揭示了与光合参数相关的显著和潜在 QTL 及其对这些性状的干旱胁迫效应。该研究为斑豆在干旱胁迫和充分供水条件下光合性状对干旱胁迫的响应以及遗传特征如何控制这些性状提供了基础认识。
