Vulnerability of European wheat to extreme heat and drought around flowering under future climate

Abstract

Identifying the future threats to crop yields from climate change is vital to underpin the continuous production increases needed for global food security. In the present study, the vulnerability of European wheat yield to heat and drought stresses around flowering under climate change was assessed by estimating the 95-percentiles of two indices at flowering under rain-fed conditions: the heat stress index (HSI95) and the drought stress index (DSI95). These two indices represent the relative yield losses due heat stress or drought stress around flowering that could be expected to occur once every 20 years on average. The Sirius wheat model was run under the predicted 2050-climate at 13 selected sites, representing the major wheat-growing regions in Europe. A total of 19 global climate models (GCMs) from the CMIP5 ensemble were used to construct local-scale climate scenarios for 2050 (RCP8.5) by downscaling GCMs climate projections with the LARS-WG weather generator. The mean DSI95 due to extreme drought around flowering under the baseline climate (1981–2010) was large over Europe (DSI95 ∼ 0.28), with wide site variation (DSI95 ∼ 0.0–0.51). A reduction of 12% in the DSI95 was predicted under the 2050-climate; however, vulnerability due to extreme drought around flowering would remain a major constraint to wheat yield (DSI95 ∼ 0–0.57). In contrast, HSI95 under the baseline climate was very small over Europe (HSI95 ∼ 0.0–0.11), but was predicted to increase by 79% (HSI95 ∼ 0.0–0.23) under the 2050-climate, categorising extreme heat stress around flowering as an emergent threat to European wheat production. The development of wheat varieties that are tolerant to drought and heat stresses around flowering, is required, if climate change is not to result in a reduction of wheat yield potential under the future climate in Europe.

The Response of Chromosomally Engineered Durum Wheat-Thinopyrum ponticum Recombinant Lines to the Application of Heat and Water-Deficit Stresses: Effects on Physiological, Biochemical and Yield-Related Traits

“…Further confirmation of the very promising behaviour of R5+, besides that of R5-derived secondary recombinants, and, to some extent, of R112+, comes from the recent results of field trials carried out in the natural stressful conditions of Algeria, Italy and Turkey [ 84 , 85 ]. No doubt, improving abiotic stress tolerance in wheat is essential to achieve yield stability and to decrease the yield gap under changing climate [ 1 , 6 , 31 , 86 ]. The evidence reported here substantiates how, for this and other key targets, the use of chromosome engineering to harness wild relatives’ useful attributes [ 19 , 20 , 21 , 22 ] is an effective strategy to develop stable and functional genotypes for large-scale applications.…”

“…Plants, as sessile organisms, cannot escape from unfavourable environments; therefore, the ability to activate effective adaptive mechanisms against abiotic stress holds great importance in view of yield preservation. Both high temperature peaks and heat waves occurring during the reproductive phase, particularly at flowering, are detrimental to wheat yield formation, with excess temperatures above the optimal 21 °C leading to floret abortion, pollen sterility and finally decreased grain number and yield [ 30 , 31 ]. Similarly, water-deficit occurrence around anthesis affects many key traits related to spike and plant fertility, such as fertile florets per spikelet and grain number per spike and per plant [ 32 , 33 ].…”

Enzymatic and biochemical responses to high temperatures and drought stress during the reproductive stage in lentil (Lens Culinaris Medik.)

“…According to Wahid et al 19 , high temperatures can be accompanied by drought due to rapid water evaporation from the plant and soil surface. High temperature and drought stress have been studied in a variety of plant species, including wheat 20 , barley 21 , maize 22 , chickpea 23 , lentil 24 and soybean 25 . However, the combined effects of high temperatures and drought on plant growth, productivity and quality are more severe than the individual effects, with the reproductive phase being more vulnerable than the vegetative stage 26 .…”

Improvement of Plant Responses by Nanobiofertilizer: A Step towards Sustainable Agriculture

“…When plants are exposed to adverse conditions, the rate of formation of reactive oxygen species (ROS) becomes high, which causes oxidative stress, reduces the membranes’ stability, and affects the structure and functions of organelles in the plant cells. If the stress occurs at the anthesis stage, the ovaries are aborted, and the fertilization rate is reduced [ 10 ]. There is a need to develop environmentally friendly strategies for the amelioration of stresses and to increase the yield of crops.…”