Adaptive Traits to Improve Durum Wheat Yield in Drought and Crown Rot Environments
Adaptive Traits to Improve Durum Wheat Yield in Drought and Crown Rot Environments
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DOI：
10.3390/ijms21155260
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发表时间：
2020-08-01
影响因子：
5.6
通讯作者：
Hickey, Lee T.
中科院分区：
文献类型：
--
作者：
Alahmad, Samir;Kang, Yichen;Hickey, Lee T.
硬粒小麦（Triticum turgidum L.）硬粒亚种）的生产可能由于冠腐病（CR）而遭受显著的产量损失。当疾病感染与末期干旱同时发生时，损失通常会加剧。硬粒小麦对CR非常敏感，并且抗性种质目前在精英育种库中不可用。我们假设，部署生理特性的干旱适应，如最佳的根系结构，以减少水分胁迫，可能会减少由于CR感染的损失。本研究评估了一个子集的行从巢式关联映射人口的持绿性状，CR发病率和产量在田间试验以及根性状在控制条件下。每周测量的归一化差异植被指数（NDVI）在外地被用来模拟冠层衰老，并确定每个基因型的持绿性状。使用DArTseq分子标记的全基因组关联研究鉴定了染色体6 B（qCR-6 B）上与CR耐受性和保绿相关的数量性状位点（QTL）。本研究利用6个不同环境（包括2个高CR病压环境）的产量数据，探讨了根角QTLqSRA-6A的主效QTL qCR-6 B的价值。在无CR条件下，qSRA-6A的有利等位基因提供了0.57 t中心点ha（-1）的平均产量优势，而在有CR条件下，qSRA-6A和qCR-6 B的有利等位基因组合导致了0.90 t中心点ha（-1）的产量优势。本研究结果突出了地上部和地下部生理性状相结合以提高产量潜力的价值。我们预计，这些见解将有助于育种家设计改进的硬粒小麦品种，减轻由于水分亏缺和CR的生产损失。
Durum wheat (Triticum turgidumL. ssp.durum) production can experience significant yield losses due to crown rot (CR) disease. Losses are usually exacerbated when disease infection coincides with terminal drought. Durum wheat is very susceptible to CR, and resistant germplasm is not currently available in elite breeding pools. We hypothesize that deploying physiological traits for drought adaptation, such as optimal root system architecture to reduce water stress, might minimize losses due to CR infection. This study evaluated a subset of lines from a nested association mapping population for stay-green traits, CR incidence and yield in field experiments as well as root traits under controlled conditions. Weekly measurements of normalized difference vegetative index (NDVI) in the field were used to model canopy senescence and to determine stay-green traits for each genotype. Genome-wide association studies using DArTseq molecular markers identified quantitative trait loci (QTLs) on chromosome 6B (qCR-6B) associated with CR tolerance and stay-green. We explored the value ofqCR-6Band a major QTL for root angle QTLqSRA-6Ausing yield datasets from six rainfed environments, including two environments with high CR disease pressure. In the absence of CR, the favorable allele forqSRA-6Aprovided an average yield advantage of 0.57 t center dot ha(-1), whereas in the presence of CR, the combination of favorable alleles for bothqSRA-6AandqCR-6Bresulted in a yield advantage of 0.90 t center dot ha(-1). Results of this study highlight the value of combining above- and belowground physiological traits to enhance yield potential. We anticipate that these insights will assist breeders to design improved durum varieties that mitigate production losses due to water deficit and CR.