SEASONAL-CHANGES IN WHEAT-GRAIN QUALITY ASSOCIATED WITH HIGH-TEMPERATURES DURING GRAIN FILLING
SEASONAL-CHANGES IN WHEAT-GRAIN QUALITY ASSOCIATED WITH HIGH-TEMPERATURES DURING GRAIN FILLING
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DOI：
10.1071/ar9910021
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发表时间：
1991-01-01
影响因子：
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通讯作者：
BARLOW, EWR
中科院分区：
文献类型：
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作者：
BLUMENTHAL, CS;BATEY, IL;BARLOW, EWR
在温室试验、田间试验和作物样品中，小麦在成熟过程中暴露于高于正常温度的条件下，产生的籽粒面团特性较弱。对1960/61年至1988/89年的优质硬麦样品进行了回顾，面团性能特别弱的季节恰好是灌浆期（10 - 12月）超过35℃的时间最多的年份。1988年为期5天的热应激提供了在野外直接调查热应激影响的机会。面团性能的减弱表明，对于四个品种，面团发育时间较长，在Farinograph中分解速度较快，并且在Extensograph中抗伸性（在5厘米处）较短。这些变化（以及温室种植谷物的类似变化）伴随着麦胶蛋白（单体）比例的增加。这种增加与热胁迫有关，证明了在培养的热胁迫头中，C-14氨基酸在麦胶蛋白部分中的积累增加。这些结果支持了一种假设，即籽粒灌浆期间的高温触发了小麦麦胶蛋白基因的热休克元件，导致成熟的籽粒含有更多的麦胶蛋白，从而产生较弱的面团。
Wheat plants exposed to higher than usual temperatures during ripening produced grain with weaker dough properties in glasshouse, field experiments and crop samples. In a review of Prime Hard wheat samples from 1960/61 to 1988/89, those seasons when the dough properties were particularly weak coincided with the years when the number of hours over 35-degrees-C during the grain filling period (October to December) was greatest.A five-day period of heat stress in 1988 provided an opportunity to directly investigate the effects of heat stress in the field. A weakening of dough properties was shown, for four varieties, by longer dough development times and faster breakdown in the Farinograph and also by shorter resistance to extension (at 5 cm) in the Extensograph.These (and similar changes for glasshouse grown grain) were accompanied by an increase in the proportion of gliadin (monomeric) proteins. That this increase was associated with the heat stress was shown by demonstrating increased accumulation of C-14 amino acids into the gliadin fraction for heat-stressed heads in culture.These results support the hypothesis that episodes of high temperature during grain filling activate the heat shock elements of gliadin genes in wheat causing the mature grain to contain more gliadin and thus to produce weaker doughs.