The University of Sydney, School of Life and Environmental Sciences, Plant Breeding Institute and Sydney Institute of Agriculture, Narrabri 2390, NSW, Australia; Australian Grain Technologies Pty Ltd, Roseworthy 5371, SA, Australia.
The University of Sydney, School of Life and Environmental Sciences, Plant Breeding Institute and Sydney Institute of Agriculture, Narrabri 2390, NSW, Australia.
Plant Sci. 2021 Mar;304:110738. doi: 10.1016/j.plantsci.2020.110738. Epub 2020 Nov 4.
Wheat is sensitive to heat stress, particularly during grain filling, and this reduces grain yield. Ancestral wheat species, such as emmer wheat (Triticum dicoccon Schrank), represent potential sources of new genetic diversity for traits that may impact wheat responses to heat stress. However, the diversity available in emmer wheat has only been explored superficially. Recently developed emmer derived hexaploid wheat genotypes were evaluated for physiological, phenological and agronomic traits in a multi-environment, multi-season strategy. The emmer-based hexaploid lines were developed from crosses and backcrosses to 9 hexaploid recurrent parents and these genotypes and 7 commercial cultivars were evaluated under two times of sowing (E1 and E2) in the field for three consecutive years (2014-2016). The materials were genotyped using a 90 K SNP platform and these data used to estimate the contribution of emmer wheat to the progeny. Significant phenotypic and genetic variation for traits were observed. Higher temperature during reproductive development and grain filling reduced trait expression. Emmer progeny with greater trait values than their recurrent parents and commercial cultivars in both environments were found. Derivatives with higher physiological trait values yielded well in both environments; as indicated by the clustering of genotypes. The emmer wheat parent contributed between 1 and 43 % of the genome of the emmer-based hexaploid progeny, and progeny with greater emmer contribution had superior trait values in both environments. These results showed a positive effect of direct emmer introgression on wheat performance under heat stress. Mitigation of high temperature stress through the introgression of favorable alleles from wheat close relatives into modern wheat cultivars is possible.
小麦对热应激敏感，特别是在灌浆期，这会降低籽粒产量。野生近缘种小麦，如二粒小麦（Triticum dicoccon Schrank），代表了新的遗传多样性的潜在来源，这些多样性可能影响小麦对热应激的响应。然而，野生近缘种小麦中的多样性仅被初步探索。最近开发的六倍体小麦衍生系，在多环境、多季节策略中评估了其生理、物候和农艺性状。这些基于二粒小麦的六倍体系是通过杂交和回交，与 9 个六倍体轮回亲本得到的，这些基因型和 7 个商业品种在田间进行了两次播种（E1 和 E2），连续三年（2014-2016 年）进行了评估。使用 90K SNP 平台对材料进行了基因型分析，并使用这些数据估计了二粒小麦对后代的贡献。观察到性状的表型和遗传变异显著。生殖发育和灌浆期较高的温度降低了性状的表达。在两个环境中，发现了具有比轮回亲本和商业品种更高性状值的二粒小麦衍生系。在两个环境中，具有较高生理性状值的衍生系产量良好；这表明基因型聚类。二粒小麦亲本对基于二粒小麦的六倍体后代基因组的贡献在 1%到 43%之间，在两个环境中，具有更多二粒小麦贡献的后代具有更高的性状值。这些结果表明，直接将二粒小麦导入小麦中对提高小麦在热应激下的表现有积极影响。通过将小麦近缘种的有利等位基因导入现代小麦品种来缓解高温胁迫是可能的。
