Post-anthesis heat and a Gpc-B1 introgression have similar but non-additive effects in bread wheat

Abstract

Abstract. High temperatures during grain filling can reduce the yield of wheat and affect its grain protein concentration. The Gpc-B1 locus of wheat also affects grain protein concentration, but it is not known whether its effects interact with those of heat. The aim of this study was to investigate the effects of high temperature in lines with and without functional (high-protein) alleles at Gpc-B1. A highly replicated experiment was conducted in a glasshouse under control conditions (24/18 C, 14/10 h day/night), with half of the plants of each line or cultivar put into a heat chamber (37/27 C, 14/10 h day/ night) at 15 days after anthesis for 3 days. Backcross derivatives with the Gpc-B1 introgression segment differed from their recurrent parents more than those without that segment. In some respects, the effects of the Gpc-B1 introgression were similar to those of the heat treatment: both could accelerate peduncle senescence, increase grain protein content and increase the percentage of unextractable polymeric protein. Unlike the heat treatment, Gpc-B1 did not reduce grain weight, indicating that factors that hasten senescence do not necessarily limit grain size. The presence of the Gpc-B1 segment did not exacerbate the effects of heat stress on any trait.

Effects of heat exposure from late sowing on the agronomic and technological quality of tetraploid wheat

“…Heat stress (defined here as >30°C) reduces final grain size mostly when it occurs early in grain filling (Stone & Nicolas, ; Tashiro & Wardlaw, ,b). Heat stress during early grain filling can also affect grain characteristics relating to quality, such as grain protein % and UPP% (Maphosa, Collins, Taylor, & Mather, ; Stone & Nicolas, ). For the current study, early grain filling was defined as the first 20 days after anthesis (anthesis calculated as 5–10 days after awn emergence; N. Collins, unpublished data).…”

Genetic control of grain protein, dough rheology traits and loaf traits in a bread wheat population grown in three environments

“…The parental cultivars were chosen on the basis of their contrasting physiological and agronomic performance under drought and heat stress conditions, with Gladius being the drought and heat tolerant parent and Drysdale more water use efficient, producing more biomass per unit area per unit of water (Fleury et al, 2010). As shown in Table 1, these cultivars differ for major phenology genes (Eagles et al, 2009), yet they head or reach anthesis within five days of each other (Maphosa et al, 2014a(Maphosa et al, , 2014b. In environments in which they head at different times, Drysdale heads before Gladius.…”

Truncation of grain filling in wheat (Triticum aestivum) triggered by brief heat stress during early grain filling: association with senescence responses and reductions in stem reserves

“…Both experiments were sown at the same time in late winter (early August 2013) and grown in the same naturally lit greenhouse compartment (The Plant Accelerator, the University of Adelaide, Waite Campus, Adelaide). Plant growth and heat stress conditions were similar to those of Maphosa et al (2014). Plants were pruned back to the single main culm by removing tillers as they appeared.…”