Biotechnology and Biosafety Research Center, Agricultural Research Corporation, P.O. Box 30, Shambat, Khartoum North, Sudan.
Arid Land Research Center, Tottori University, 1390 Hamasaka, Tottori 680-0001, Japan.
Biomed Res Int. 2018 Nov 18;2018:7082095. doi: 10.1155/2018/7082095. eCollection 2018.
Stay-green trait enhances sorghum adaptation to post-flowering drought. Six stay-green backcross introgression lines (BILs) carrying one or more stay-green QTLs (Stg1-4) and their parents were characterized under non-stress (W: 100% of soil field capacity (FC)) and two levels of post-flowering drought (W: 75% FC; W: 50% FC) in a controlled condition. We aimed to study the response and identify the drought threshold of these QTLs under different levels of post-flowering drought and find traits closely contributing to grain yield (GY) under different drought severity. W caused the highest reduction in BILs performance. From W to W, the GY of the recurrent parent reduced by 70%, whereas that of the BILs reduced by only 36%. W and W induce different behavior/response compared to W. Harvest index contributed to the GY under the three water regimes. For high GY under drought transpiration rate at the beginning of drought and mid-grain filling was important at W, whereas it was important at mid-grain filling and late-grain filling at W. Stay-green trait can be scored simply with the relative number of green leaves/plants under both irrigated and stress environments. QTL pyramiding might not always be necessary to stabilize or increase the GY under post-flowering drought. The stay-green QTLs increase GY under drought by manipulating water utilization depending on drought severity.
持绿特性增强高粱开花后干旱适应能力。六个持绿回交导入系（BILs）携带一个或多个持绿 QTL（Stg1-4）及其亲本在非胁迫条件下（W：土壤田间持水量的 100%（FC））和两个开花后干旱水平下进行了特征描述（W：75% FC；W：50% FC）在受控条件下。我们旨在研究这些 QTL 在不同水平的开花后干旱下的反应，并确定干旱阈值，并找到在不同干旱严重程度下与粒重（GY）密切相关的性状。W 导致 BILs 性能的最大降低。从 W 到 W，轮回亲本的 GY 减少了 70%，而 BILs 的 GY 仅减少了 36%。W 和 W 与 W 相比诱导不同的行为/反应。在三种水分条件下，收获指数对 GY 有贡献。对于干旱下的高 GY，在 W 下，干旱开始时的蒸腾速率和中期灌浆对 GY 很重要，而在 W 下，中期灌浆和后期灌浆对 GY 很重要。持绿特性可以在灌溉和胁迫环境下通过相对绿叶/植物数量进行简单评分。在开花后干旱下，不一定总是需要 QTL 聚合来稳定或增加 GY。持绿 QTL 通过根据干旱严重程度操纵水分利用来增加干旱下的 GY。
