Exotic alleles contribute to heat tolerance in wheat under field conditions

Abstract

Global warming poses a major threat to food security and necessitates the development of crop varieties that are resilient to future climatic instability. By evaluating 149 spring wheat lines in the field under yield potential and heat stressed conditions, we demonstrate how strategic integration of exotic material significantly increases yield under heat stress compared to elite lines, with no significant yield penalty under favourable conditions. Genetic analyses reveal three exotic-derived genetic loci underlying this heat tolerance which together increase yield by over 50% and reduce canopy temperature by approximately 2 °C. We identified an Ae. tauschii introgression underlying the most significant of these associations and extracted the introgressed Ae. tauschii genes, revealing candidates for further dissection. Incorporating these exotic alleles into breeding programmes could serve as a pre-emptive strategy to produce high yielding wheat cultivars that are resilient to the effects of future climatic uncertainty.

Ecogeographic signals of local adaptation in a wild relative help to identify variants associated with improved wheat performance under drought stress

“…Introgression from Ae. tauschii into spring wheat was associated with low CT and improved yield under heat stress (Molero et al, 2023). Previously, we showed that the difference in mean yield of some Ae.…”

“…Consistent with these results, several high-yielding drought tolerant cultivars have been derived from synthetic wheat lines created using Ae. tauschii as one of the parents (Rosyara et al 2019; Molero et al, 2023; Pinto and Reynolds 2015). Our analyses suggest that improved performance of wheat introgression lines could be largely attributed to introduction of climate-adaptive alleles that show association with environmental variation in Ae.…”

“…For example, it was demonstrated that these ancestors of wheat have potential to improve adaptation to water limiting conditions and heat, and increase biomass and harvest index Molero et al, 2023). However, considering the broad adaptive potential of these species reflected in their wide geographic distribution, the question remains of how effective these efforts were at capturing adaptive diversity of Ae.…”

“…tauschii , the allelic diversity of these ancestors was introduced into multiple international breeding programs from CIMMYT, ICARDA, China, Australia, United Kingdom, and United States (Pestsova et al, 2004; Börner et al, 2015). For example, it was demonstrated that these ancestors of wheat have potential to improve adaptation to water limiting conditions and heat, and increase biomass and harvest index (Singh et al, 2019; Molero et al, 2023). However, considering the broad adaptive potential of these species reflected in their wide geographic distribution, the question remains of how effective these efforts were at capturing adaptive diversity of Ae.…”

Agroecological genetics of biomass allocation in wheat uncovers genotype interactions with canopy shade and plant size

“…Changes in the plant HI due to crowding reflect the degree of competition among plants in the field (Denison, 2012), and identifying the genetic factors responsible for such responses in resource allocation can facilitate the development of high‐yielding cooperative genotypes. Although previous studies have looked into HI from a genetic point of view (Molero et al ., 2019, 2023; Dreisigacker et al ., 2021; Sierra‐Gonzalez et al ., 2021; Ruiz et al ., 2023), as far as we know, no genetic investigation has been carried out to analyse the plasticity in resource allocation.…”