Pérez-Gianmarco Thomas I, Slafer Gustavo A, González Fernanda G
Department of Crop and Forest Sciences, University of Lleida, Av. Rovira Roure 191, 25198 Lleida, Spain.
CITNOBA, CONICET-UNNOBA. Monteagudo 2772, B2700KIZ Pergamino, Buenos Aires, Argentina.
Funct Plant Biol. 2018 May;45(6):645-657. doi: 10.1071/FP17195.
Fine tuning wheat phenology is of paramount importance for adaptation. A better understanding of how genetic constitution modulates the developmental responses during pre-anthesis phases would help to maintain or even increase yield potential as temperature increases due to climate change. The photoperiod-sensitive cultivar Paragon, and four near isogenic lines with different combinations of insensitivity alleles (Ppd-A1a, Ppd-B1a, Ppd-D1a or their triple stack) were evaluated under short (12h) and long (16h) photoperiods. Insensitivity alleles decreased time to anthesis and duration of the three pre-anthesis phases (vegetative, early reproductive and late reproductive), following the Ppd-D1a > Ppd-A1a > Ppd-B1a ranking of strength. Stacking them intensified the insensitivity, but had no additive effect over that of Ppd-D1a. The late reproductive phase was the most responsive, even exhibiting a qualitative response. Leaf plastochron was not affected but spikelet plastochron increased according to Ppd-1a ranking of strength. Earlier anthesis resulted from less leaves differentiated and a fine tuning effect of accelerated rate of leaf appearance. None of the alleles affected development exclusively during any particular pre-anthesis phase, which would be ideal for tailoring time to anthesis with specific partitioning of developmental time into particular phases. Other allelic variants should be further tested to this purpose.
精细调控小麦物候对适应性至关重要。更好地理解遗传构成如何在抽穗前阶段调节发育反应，将有助于在气候变化导致温度升高的情况下维持甚至提高产量潜力。在短日照（12小时）和长日照（16小时）条件下，对光周期敏感品种Paragon以及四个具有不同不敏感等位基因组合（Ppd-A1a、Ppd-B1a、Ppd-D1a或其三基因叠加）的近等基因系进行了评估。不敏感等位基因缩短了抽穗时间以及抽穗前三个阶段（营养生长、早期生殖生长和晚期生殖生长）的持续时间，其强度顺序为Ppd-D1a > Ppd-A1a > Ppd-B1a。将它们叠加增强了不敏感性，但对Ppd-D1a没有累加效应。晚期生殖生长阶段反应最为敏感，甚至表现出质的反应。叶龄期不受影响，但小穗叶龄期根据Ppd-1a强度顺序增加。抽穗提前是由于分化出的叶片较少以及叶片出现速率加快的微调效应。没有一个等位基因仅在任何特定的抽穗前阶段影响发育，这对于将发育时间特定分配到特定阶段来定制抽穗时间是理想的。为此应进一步测试其他等位基因变体。
