Increasing wheat yield potential and stability under climate change will require tolerance to drought during reproductive development

Abstract

Short periods of extreme weather, such as a spell of high temperature or drought during a  sensitive stage of development, could result in substantial yield losses due to reduction of sink  capacity resulting from decrease in grain number and grain size. In a modelling study  (Stratonovitch & Semenov 2015), heat tolerance around flowering in wheat was identified as a  key trait for increased yield potential in Europe under climate change. Ji et all (Ji et al. 2010)  demonstrated cultivar specific responses of yield to drought stress around flowering in wheat.  They hypothesised that carbohydrate supply to anthers may be the key in maintaining pollen  fertility and grain number in wheat. It was shown in (Nuccio et al. 2015) that genetically modified  varieties of maize that increase the concentration of sucrose in ear spikelets, performed better  under non-drought and drought conditions in field experiments.  The objective of this modelling study was to assess potential benefits of tolerance to drought  during reproductive development for wheat yield potential and yield stability across Europe. We  used the Sirius wheat model to optimise wheat ideotypes for 2050 (HadGEM2, RCP8.5) climate  scenarios at selected European sites. At those sites where water could be limited, ideotypes  sensitive to drought produced substantially lower mean yields and higher yield variability  compare with tolerant ideotypes. Therefore, tolerance to drought during reproductive  development will be required for wheat cultivars optimised for the future climate in Europe in  order to achieve high yield potential and high yield stability.