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

Abstract

Background and objectives Heat stress is a major limiting factor to wheat yield that also impacts on grain quality, and its incidence is likely to increase. Thirty‐seven durum wheats were grown in irrigated replicated field trials over two seasons in Australia, normal sown (NS) or a 2‐month late sown (LS). Agronomic and technological quality traits were examined. Findings Later sowing exposed the crop to more days at temperatures of 30°C and above indicating more heat stress while the irrigation ensured no drought stress. Relative to NS, LS reduced yield, grain weight, test weight, and milling yield but grain vitreousness and hardness either increased or decreased depending on the trial. However, LS had positive effects on increasing protein content, dough quality indicators, and increased the proportion of high molecular weight gluten polymer. LS also enhanced pasta end‐use traits, increasing pasta yellowness and firmness and decreasing cooking loss. Genotypes that showed relatively stable yield and grain characteristics under LS were identified (Caparoi, Jandaroi, Kalka, Kronos, Saintly, and WID802). Conclusions These findings suggest that the heat stress experienced enhanced dough and pasta quality, despite having a negative impact on yield and physical grain characteristics. Genotypes were identified that represent potential sources of heat tolerance that could be useful in breeding to help limit the undesirable effects of heat stress on durum production. Significance and novelty Late sowing of wheat is a good strategy to obtain exposure to heat stress in the Australian environment and can be used to select genotypes with better yield and quality stability.

Genetic improvement in grain yield and quality of Australian durum wheat over six decades of breeding

“…Also, large size kernels have a higher percentage of endosperm which translates to higher semolina yield. There was a strong negative correlation in this study between TGW and SCR ( r = −0.73) supported by other studies in both durum (Kadkol et al, 2020; Sissons et al, 2018) and bread wheat (Maphosa et al, 2014; Riaz, 2020) and therefore selecting for higher TGW could lower SCR. In our study, Dural, the oldest variety, showed high TGW and low SCR which goes against the trend with the year of release.…”

Grain and flour quality of wheat genotypes grown under heat stress

“…The increase in WG, DG, and GI of wheat genotypes is in agreement with Bonfil et al (2015) in common wheat and Sissons et al (2018) in durum wheat. An increase in the synthesis of gliadin-like heat shock elements (HSE), which reduces the ratio of glutenin to gliadin, and ultimately lessens the GI, may be one possible explanation ( Li et al, 2013 ).…”

Pleiotropic and independent genetic loci underlie resistance to grain shattering in standing crop of modern wheat

“…All experiments were fertilized at the time of sowing with mono-ammonium phosphate (MAP) at the rate of 100kg ha − 1 . Weed and disease control, including irrigation, followed standard procedures described in Sissons et al (2018).…”

“…Plant height was measured in each plot, from soil surface to tip of the awns and de ned as the average of three locations within each plot. Phenology was measured as the date of awn emergence, de ned in days from sowing to when awns on 50% of the plants in a plot were approximately 1 cm above the ag leaf auricle (Sissons et al 2018).…”