Pradhan Gautam P, Prasad P V Vara, Fritz Allan K, Kirkham Mary B, Gill Bikram S
Department of Agronomy, Kansas State University, 2004 Throckmorton Plant Sciences Center, Manhattan, KS 66506, USA.
Department of Plant Pathology, Kansas State University, 4024 Throckmorton Plant Sciences Center, Manhattan, KS 66506, USA.
Funct Plant Biol. 2012 Apr;39(3):190-198. doi: 10.1071/FP11245.
Drought and high temperature often occurs simultaneously, causing significant yield losses in wheat (Triticum aestivum L.). The objectives of this study were to: (i) quantify independent and combined effects of drought and high temperature stress on synthetic hexaploid wheat genotypes at anthesis and at 21 days after anthesis; and (ii) determine whether responses to stress varied among genotypes. Four synthetic hexaploid and two spring wheat genotypes were grown from emergence to anthesis (Experiment I) and emergence to 21 days after anthesis (Experiment II), with full irrigation and 21/15°C day/night temperature. Thereafter, four treatments were imposed for 16 days as (a) optimum condition: irrigation+21/15°C, (b) drought stress: withhold irrigation+21/15°C, (c) high temperature stress: irrigation+36/30°C and (d) combined stress: withhold irrigation+36/30°C. Results indicated a decrease in leaf chlorophyll, individual grain weight and grain yield in an increasing magnitude of drought<high temperature<combined stress. There were 69, 81 and 92% grain yield decreases in Experiment I and 26, 37 and 50% in Experiment II under drought, high temperature and combined stress respectively. Synthetic hexaploid wheat genotypes varied in their response to stresses. Genotypes ALTAR 84/AO'S' and ALTAR 84/Aegilops tauschii Coss. (WX 193) were least affected by combined stress in Experiments I and II respectively. Overall, combined effect of drought+high temperature stress was more detrimental than the individual stress and the interaction effect was hypo-additive in nature.
干旱和高温常常同时出现，导致小麦（普通小麦）产量大幅下降。本研究的目的是：（i）量化干旱和高温胁迫在开花期和开花后21天对人工合成六倍体小麦基因型的独立和综合影响；（ii）确定不同基因型对胁迫的反应是否存在差异。四个人工合成六倍体和两个春小麦基因型从出苗生长至开花期（实验I）以及从出苗生长至开花后21天（实验II），期间充分灌溉，日/夜温度为21/15°C。此后，施加四种处理，持续16天，分别为：（a）最佳条件：灌溉+21/15°C，（b）干旱胁迫：停止灌溉+21/15°C，（c）高温胁迫：灌溉+36/30°C，（d）复合胁迫：停止灌溉+36/30°C。结果表明，叶片叶绿素、单粒重和籽粒产量随干旱<高温<复合胁迫程度的增加而降低。在实验I中，干旱、高温和复合胁迫下的籽粒产量分别下降了69%、81%和92%；在实验II中，分别下降了26%、37%和50%。人工合成六倍体小麦基因型对胁迫的反应各不相同。在实验I和实验II中，基因型ALTAR 84/AO'S'和ALTAR 84/节节麦（WX 193）分别受复合胁迫的影响最小。总体而言，干旱+高温胁迫的综合影响比单一胁迫更具危害性，且相互作用效应本质上是次加性的。
