Guo Zifeng, Chen Dijun, Röder Marion S, Ganal Martin W, Schnurbusch Thorsten
Independent Heisenberg Research Group Plant Architecture, Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, 06466, Germany.
Department of Breeding Research, Research Group Image Analysis, Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, 06466, Germany.
Plant J. 2018 Jun 15. doi: 10.1111/tpj.13998.
Flowering time is an important factor affecting grain yield in wheat. In this study, we divided reproductive spike development into eight sub-phases. These sub-phases have the potential to be delicately manipulated to increase grain yield. We measured 36 traits with regard to sub-phase durations, determined three grain yield-related traits in eight field environments and mapped 15 696 single nucleotide polymorphism (SNP, based on 90k Infinium chip and 35k Affymetrix chip) markers in 210 wheat genotypes. Phenotypic and genetic associations between grain yield traits and sub-phase durations showed significant consistency (Mantel test; r = 0.5377, P < 0.001). The shared quantitative trait loci (QTLs) revealed by the genome-wide association study suggested a close association between grain yield and sub-phase duration, which may be attributed to effects on spikelet initiation/spikelet number (double ridge to terminal spikelet stage, DR-TS) and assimilate accumulation (green anther to anthesis stage, GA-AN). Moreover, we observed that the photoperiod-sensitivity allele at the Ppd-D1 locus on chromosome 2D markedly extended all sub-phase durations, which may contribute to its positive effects on grain yield traits. The dwarfing allele at the Rht-D1 (chromosome 4D) locus altered the sub-phase duration and displayed positive effects on grain yield traits. Data for 30 selected genotypes (from among the original 210 genotypes) in the field displayed a close association with that from the greenhouse. Most importantly, this study demonstrated specific connections to grain yield in narrower time windows (i.e. the eight sub-phases), rather than the entire stem elongation phase as a whole.
抽穗期是影响小麦籽粒产量的一个重要因素。在本研究中，我们将生殖穗发育划分为八个亚阶段。这些亚阶段有可能被精细调控以提高籽粒产量。我们测量了与亚阶段持续时间相关的36个性状，在八个田间环境中测定了三个与籽粒产量相关的性状，并在210个小麦基因型中定位了15696个单核苷酸多态性（SNP，基于90k Infinium芯片和35k Affymetrix芯片）标记。籽粒产量性状与亚阶段持续时间之间的表型和遗传关联显示出显著的一致性（Mantel检验；r = 0.5377，P < 0.001）。全基因组关联研究揭示的共享数量性状位点（QTL）表明籽粒产量与亚阶段持续时间密切相关，这可能归因于对小穗起始/小穗数（二棱期至顶小穗期，DR - TS）和同化物积累（绿花药期至开花期，GA - AN）的影响。此外，我们观察到2D染色体上Ppd - D1位点的光周期敏感等位基因显著延长了所有亚阶段的持续时间，这可能是其对籽粒产量性状产生积极影响的原因。4D染色体上Rht - D1位点的矮化等位基因改变了亚阶段持续时间，并对籽粒产量性状表现出积极影响。田间30个选定基因型（来自最初的210个基因型）的数据与温室中的数据显示出密切关联。最重要的是，本研究证明了在更窄的时间窗口（即八个亚阶段）而非整个茎伸长阶段与籽粒产量存在特定联系。
