Department of Biology, School of Science and Technology, University of Nairobi, Nairobi, Kenya.
Department of Plant Science, University of Zambia, Great East Road, Lusaka, Zambia.
Theor Appl Genet. 2023 Oct 12;136(11):222. doi: 10.1007/s00122-023-04463-2.
Quantitative Trait Loci "hotspots" for drought tolerance were identified on chromosomes Pv06, Pv07 and Pv10 of common bean. Drought is a major production constraint of common bean (Phaseolus vulgaris L.) worldwide. The objective of this study was to identify the Quantitative Trait Loci (QTL) for drought tolerance in an Andean population of Recombinant Inbred Lines (RILs). A total of 155 F RILs derived from a cross between Kijivu (drought tolerant) and Bukoba (drought susceptible) were evaluated for drought tolerance in field and pot experiments. Four field experiments were conducted at three locations in Zambia in 2020 and 2021. All field trials were conducted in the dry season under irrigation. The 155 RILs were genotyped with 11,292 SNPs, and composite interval mapping was conducted to identify QTL for drought tolerance. Seed yield for Kijivu under drought stress was consistently higher than for Bukoba across all four field trials. A total of 60 QTL were identified for morphological, agronomic, and physiological traits under drought stress and non-stress conditions. However, the majority of these QTL were specific to drought stress. QTL "hotspots" for drought tolerance were identified on chromosomes Pv06, Pv07, and Pv10. Extensive co-localizations for agronomic and morpho-physiological traits under drought stress were observed at the three drought-tolerance QTL hotspots. Additionally, these three QTL hotspots overlapped with previously identified QTL for drought tolerance, while several others identified QTL are novel. The three identified QTL hotspots could be used in future marker-assisted selection for drought tolerance in common bean.
在普通菜豆（Phaseolus vulgaris L.）的 Pv06、Pv07 和 Pv10 染色体上鉴定到耐旱性数量性状基因座“热点”。干旱是全球普通菜豆生产的主要限制因素。本研究的目的是鉴定安第斯种群重组自交系（RILs）的耐旱性数量性状基因座（QTL）。总共评估了来自 Kijivu（耐旱）和 Bukoba（耐旱）之间杂交的 155 个 F RIL 对田间和盆栽试验中的耐旱性。2020 年和 2021 年在赞比亚的三个地点进行了 4 次田间试验。所有田间试验均在旱季进行灌溉。使用 11,292 个 SNP 对 155 个 RIL 进行了基因型分析，并进行了复合区间作图以鉴定耐旱性 QTL。在所有 4 个田间试验中，Kijivu 在干旱胁迫下的种子产量始终高于 Bukoba。在干旱胁迫和非胁迫条件下共鉴定到 60 个与形态、农艺和生理性状相关的 QTL。然而，这些 QTL 大多数是特定于干旱胁迫的。在 Pv06、Pv07 和 Pv10 染色体上鉴定到耐旱性 QTL“热点”。在三个耐旱性 QTL 热点处观察到干旱胁迫下农艺和形态-生理性状的广泛共定位。此外，这三个 QTL 热点与先前鉴定到的耐旱性 QTL 重叠，而其他一些鉴定到的 QTL 是新的。这三个鉴定出的 QTL 热点可用于未来普通菜豆耐旱性的标记辅助选择。
