Selecting traits to increase winter wheat yield under climate change in the North China Plain

To mitigate the possible yield reduction of winter wheat under climate change in the North China Plain (NCP), cultivars with traits that could offset the negative effects of several deteriorating weather factors in the future should be developed. This study used 16 recently certified cultivars of winter wheat each season for five seasons from 2011 to 2016 under three irrigation treatments (I0: without irrigation; I1: moderate irrigation; and I2: well water supply) to examine the agronomic traits of winter wheat that may be able to reduce the negative effects of abiotic stress. Yield variation up to 32% was observed during the five seasons, indicating the significant effects of seasonal weather conditions. The yield difference among the cultivars reached 33%, indicating the benefit of selecting a better cultivar to minimize the negative effects of weather and water deficit. Cultivars with higher seed numbers per area and greater biomass usually gave better grain production under all three water supply conditions. Under good water supply conditions, sunshine duration during the vegetative growth stage significantly affected the spike numbers per area and seed numbers per spike. Diurnal temperature range (DTR) during the grain-fill stage was positively related to the seed weight. Cultivars with higher leaf photosynthetic rates and earlier anthesis dates had an advantage to relieve the influence of climate change and produced higher yield. Due to the reduced rainfall and increased atmospheric evaporation potential under the climate change background, for winter wheat grown under limited water supply, cultivars with a higher kernel Δ13C, a lower canopy temperature and a larger root system usually produced a higher yield. In general, for winter wheat grown under good water supply conditions, cultivars that had higher efficiency in dry matter assimilation and allocation performed better. Under dry conditions, cultivars with a high ability to use the soil water stored before sowing had an advantage that allowed them to produce a higher yield.