Wheat breeding highlights drought tolerance while ignores the advantages of drought avoidance: A meta-analysis
Wheat breeding highlights drought tolerance while ignores the advantages of drought avoidance: A meta-analysis
复制标题
小麦育种强调耐旱而忽视避旱优势：荟萃分析
DOI：
10.1016/j.eja.2020.126196
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发表时间：
2021-01-01
影响因子：
5.2
通讯作者：
Xiong, Youcai
中科院分区：
文献类型：
--
作者：
Li, Pufang;Ma, Baoluo;Xiong, Youcai
作物的耐旱性和避旱性是科普干旱胁迫的重要适应机制，但它们对产量形成的贡献不同。关于这两种机制在作物长期育种中的不同作用知之甚少。通过Meta分析，研究了小麦耐旱和避旱机制对作物干旱适应的不同影响。该荟萃分析总结了283篇在国际期刊上发表的论文的结果，并说明原始小麦基因型，包括野生，栽培二倍体，四倍体和老六倍体，优先表现出干旱回避策略，表现为大根生物量，小叶面积，以及水分亏缺下气孔导度降低。现代六倍体基因型表现出较强的耐旱优势，如高的叶水势和渗透调节能力，根系较小。元分析结果表明，旱地小麦的育种过程一直在不断增强耐旱性，同时减弱了避旱性。在严重水分亏缺条件下，耐旱性较强的老六倍体小麦基因型地上生物量和产量的下降幅度小于耐旱性较强的现代基因型，而在轻度和中度水分亏缺条件下，耐旱性较强的基因型产量和地上生物量较高。元分析提供了信息，为决策现代作物育种的方向和管理措施的实施，以科普干旱压力，其频率和严重程度正在增加，随着气候变化的到来。
Crop tolerance and avoidance are critical adaptation mechanisms to cope with drought stress but they contribute differently to grain yield formation. Little is known about the different roles of these two mechanisms in longterm crop breeding. A meta-analysis was conducted to determine the different effects of drought tolerance and avoidance mechanisms on the drought adaptation of wheat crops. The meta-analysis summarized the results of 283 published papers in international journals, and illustrated that primitive wheat genotypes, including wild, cultivated diploids, tetraploids and old hexaploids, preferentially showed a drought avoidance strategy, as evidenced by large root biomass, small leaf area, and reduced stomatal conductance under water deficits. Modern hexaploid genotypes showed stronger drought tolerance advantages, such as high leaf water potential and osmotic adjustment, with a small root system. The meta-analysis indicated that the breeding process of dryland wheat has been continuously enhancing drought tolerance while weakening drought avoidance. Under severe water deficits, old hexaploid wheat genotypes with drought avoidance characteristics showed lower reduction of aboveground biomass and yield than modern genotypes with stronger drought tolerance features, while under mild and moderate water deficits genotypes with stronger drought tolerance features had higher yields and aboveground biomass. The meta-analysis provide information for making decisions on the direction of modern crop breeding and the implementing of managing practices to cope with drought stress, which frequency and severity is increasing with the advent of climate change.