Wheat Cultivars Vary Widely in Their Responses of Grain Yield and Quality to Short Periods of Post-Anthesis Heat Stress

Abstract

Short periods of high temperature (> 35�C) are common during the post-anthesis period in Australian wheat crops and have recently been shown to significantly reduce grain yield and quality. In view of this, 75 cultivars of wheat were screened for tolerance to 3 days of high temperature (max. 40�C). Detailed results for grain yield and quality are presented for five wheat cultivars in order to illustrate the wide range of responses to short periods of high temperature. Individual kernel mass decreased by up to 23%, depending on variety, and the gliadin : glutenin ratio altered in the range -9 to +18% in response to high temperature treatment, also depending on variety. Noodle swelling power was significantly affected by heat in two cultivars, but there was no significant change due to heat in the apparent amylose content in any variety. The marked response of several yield and quality components to a heat treatment lasting only ca 5% of the grain-filling period suggests that starch and protein synthesis do not immediately andlor fully recover from short, severe heat stress. In addition, we conclude that wheat shows considerable genetic variability in tolerance to short periods of high temperature for both grain yield and quality.

Responses of Three Wheat Genotypes to High Soil Temperature during Grain Filling

“…Thus, even in the same genotype, the responses to high soil temperature or high air/soil temperature were not always the same. Differential responses of yield and quality components to post-anthesis heat stress in the same wheat genotype has been reported (Stone and Nicolas, 1994).…”

IV.Heat stress in Triticum: kinetics of Fe and Mn accumulation

“…These growth conditions prompted characteristic effects of moderate high temperatures (25/32 ºC) after anthesis (Wardlaw et al, 1980; and specific behaviors (Blumenthal et al 1991a, b;Randall and Moss, 1990;Stone and Nicolas, 1994;1995) associated to heat shocks (> 32 ºC). Accordingly, as found in previous studies by our research group, after anthesis Triticum aestivum L. genotype Sever displayed an higher tolerance to heat stress than the genotype Golia (Maçãs et al, 1999;, Dias et al, 2008 and Triticum turgidum subsp.…”

Genetic analysis for grain filling duration in wheat using joint segregation analysis

“…The period of grain filling indicated the presence of an overdominance gene action that controlled this trait and other yield attributes (Akram et al, 2008). Stone and Nicolas (1994) also concluded that the period of grain filling was affected by environmental factors, especially temperature.…”