
TY  - JOUR
A1  - Wardlaw, Ian F. 
A1  - Blumenthal, Caron 
A1  - Larroque, Oscar 
A1  - Wrigley, Colin W. 
T1  - Contrasting effects of chronic heat stress and heat shock on kernel weight and flour quality in wheat
JF  - Functional Plant Biology
JO  - Functional Plant Biol.
Y1  - 2002
VL  - 29
IS  - 1
SP  - 25
EP  - 34
KW  - 
UR  - https://doi.org/10.1071/PP00147 
N2  - Phytotron studies were conducted to compare the potential effects of chronic high-temperatures (daily maxima of over 20&#x02DA;C) and heat-shock conditions (a few days of over 32&#x02DA;C), on wheat (Triticum aestivum L.) yield and quality, to form a basis for the selection of improved high-temperature tolerance in wheat. The series of heat-shock treatments were designed to provide similar heat loads, by varying the duration (number of days) of each treatment. Studies involved two cultivars, Lyallpur and Trigo 1. Both showed a reduction in kernel weight in response to chronic high day temperatures (i.e. above 18&#x02DA;C), with Trigo 1 more tolerant than Lyallpur. Kernel weight of both cultivars was also reduced by short periods of heat shock, and this was most evident at day/night temperatures above 30/25&#x02DA;C. There was no reduction in the germination of the lighter weight kernels formed under either chronic high temperature or heat-shock conditions. Dough strength, as judged by mixing time, declined in both genotypes with prolonged chronic high temperature, and also following the most extreme of the heat-shock treatments &#8212; Trigo 1 showed an ability to resist these changes better than Lyallpur. The heat-related decreases in dough strength were associated with decreases in the proportion of the larger molecular size glutenin (most &#8216;unextractable&#8217;). This change in quality was not however, associated with changes in flour protein content. 
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