Winter Wheat Photosynthesis and Grain Yield Responses to Spring Freeze
Winter Wheat Photosynthesis and Grain Yield Responses to Spring Freeze
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冬小麦光合作用和籽粒产量对春季冰冻的响应
DOI：
10.2134/agronj14.0460
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发表时间：
2015-05-01
期刊：
影响因子：
2.1
通讯作者：
Jiang, Dong
中科院分区：
文献类型：
--
作者：
Li, Xiangnan;Pu, Hanchun;Jiang, Dong
春冻严重限制了冬小麦的生长发育和籽粒产量。利用设计的气温控制装置，对两个对照品种XM21(耐低温)和XZ 24(低温敏感)进行了为期两年的田间试验，以研究春冻对小麦的生理和产量反应。这些植物生长在田间，在拔节期(Zadoks Scale 31)经历5天的春季冰冻(大约比环境温度低8摄氏度)。春冻显著降低了两个品种小麦叶片的气体交换速率和光系统II的最大量子效率。春冻条件下，XZ24的产量损失为12%~14%，XM21的产量损失为5%~6%。与XM21相比，XZ24的产量损失更大，其分蘖数和穗数的减少幅度更大。春季冻害发生在拔节期，在5d末和7d后测定时，叶片的光合作用能力降低，导致有效分蘖数减少，最终导致产量下降。这两个品种分蘖发育对春冻敏感性不同的遗传和(或)生理生化基础可进一步用于培育耐春冻胁迫的小麦新品种。
Spring freeze events seriously limit the growth, development, and grain yield of winter wheat (Triticum aestivoin L.). A 2-yr field experiment with two contrasting cultivars: XM21 (low-temperature resistant) and XZ,24 (low-temperature sensitive), was conducted using an air temperature control device designed to allow investigation of the physiological and grain yield responses to spring freeze. The plants were grown in the field and subjected to a 5-d spring freeze episode (approximately 8 degrees C lower than the ambient temperature) at jointing stage (Zadoks scale 31). Spring freeze significantly decreased gas exchange rates and maximum quantum efficiency of photosystem II in wheat leaves of both cultivars. Under spring freeze, the yield loss was 12 to 14% in XZ24 vs. 5 to 6% in XM21. Greater yield loss in XZ24 coincided with a greater reduction of tiller and spike number in XZ24 than in XM21. Spring freeze occurring at jointing stage depressed the photosynthetic capacity of the leaves when measured at the end of the 5-d period and again at 7 d later, resulting in lowered number of effective tillers, and eventually decreasing the grain yield. The genetic and/or bio-physiochemical basis for the different sensitivity of tiller development to spring freeze between the two cultivars could be further exploited for breeding new wheat cultivars tolerant to spring freeze stress.