
%0 Journal Article
%A Wardlaw, Ian F. 
%A Blumenthal, Caron 
%A Larroque, Oscar 
%A Wrigley, Colin W. 
%T Contrasting effects of chronic heat stress and heat shock on kernel weight and flour quality in wheat
%J Functional Plant Biology
%D 2002/01/16
%V 29
%N 1
%P 25-34
%K 
%R https://doi.org/10.1071/PP00147
%U https://www.publish.csiro.au/paper/PP00147 
%X 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. 
