Physiological Traits for Improving Heat Tolerance in Wheat
Physiological Traits for Improving Heat Tolerance in Wheat
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DOI：
10.1104/pp.112.207753
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发表时间：
2012-12-01
期刊：
影响因子：
7.4
通讯作者：
Reynolds, Matthew P.
中科院分区：
文献类型：
--
作者：
Mariano Cossani, C.;Reynolds, Matthew P.
小麦（Triticum aestivum）约占世界谷物面积的30%，全球种植面积超过2.2亿公顷，通常处于非生物胁迫下。小麦生长在任何发育阶段都可能受到热胁迫（HS）的损害，并且建模情景预测未来的温度甚至会更高（Easterling和Apps， 2005）。气温上升的最严重影响将发生在低纬度地区（那里种植了大约1亿公顷的小麦，生产了大约2.8亿吨粮食），而高纬度地区预计会有一些好处。就育种目标而言，根据种植制度（例如雨养与灌溉，春播与冬播）以及生物和非生物限制，在全球范围内定义了12种不同的小麦大环境（Braun et al., 2010）。虽然大环境5包括700万公顷的连续高温（例如在苏丹和印度南部和中部），但总小麦面积的一半以上已经容易出现高温期，气候模型表明平均温度进一步升高（图1；补充表S1）以及极端温度异常，这些已经可以检测到（Hansen et al., 2012）。产量损失与长期高温（生长周期的平均温度为18 -25摄氏度，灌浆期间的最高日温度高达32摄氏度）和热冲击有关，热冲击在小麦繁殖中后期，包括灌浆期间，温度超过32摄氏度（Wardlaw和Wrigley， 1994）。最近对大量国际苗期数据的分析表明，针对非生物胁迫的春小麦育种在更温暖的环境中可以获得更好的遗传收益（SM Gourdji, KL Mathews, MP Reynolds， J. Crossa和DB Lobell，未发表的数据）。本更新考虑了有证据表明遗传改良可以提高小麦对高温胁迫的适应性的生理过程和性状。小麦的生物威胁问题超出了本综述的范围，读者可以参考其他来源（Legreve和Duveiller， 2010）。
Wheat (Triticum aestivum) represents about 30% of the world's cereal area, with over 220 million ha cultivated worldwide, often under abiotic stress. Wheat growth can be impaired by heat stress (HS) at any developmental stage, and modeling scenarios predict even warmer temperatures in the future (Easterling and Apps, 2005). The worst impacts of rising temperatures will occur at low latitudes (where approximately 100 million ha of wheat are cultivated, producing approximately 280 million tons of grain), while some benefits at high latitudes are expected. In terms of breeding targets, 12 different wheat megaenvironments have been defined worldwide based on cropping system (eg rain fed versus irrigated, spring versus winter type) together with biotic and abiotic constraints (Braun et al., 2010). While megaenvironment 5 encompasses 7 million ha under continuous HS (eg in Sudan and south and central India), over one-half of the total wheat area is prone to periods of HS already, and climate models suggest further increases in average temperatures (Fig. 1; Supplemental Table S1) as well as extreme temperature anomalies, which are already detectable (Hansen et al., 2012). Yield penalties are associated with both chronically high temperatures (mean temperature of the growth cycle being 18 C-25 C, and maximum day temperatures up to 32 C during grain filling) as well as heat shocks, where temperatures greater than 32 C occur during mid or late reproductive wheat stages, including grain filling (Wardlaw and Wrigley, 1994). A recent analysis of extensive international nursery data suggests that spring wheat breeding targeted for abiotic stress delivers better genetic gains in warmer environments (SM Gourdji, KL Mathews, MP Reynolds, J. Crossa, and DB Lobell, unpublished data). This Update considers the physiological processes and traits for which there is evidence that genetic improvement could improve wheat adaptation to HS. The issue of biotic threats to wheat is beyond the scope of this review, and readers are referred to other sources (Legreve and Duveiller, 2010).