Guo Zifeng, Chen Dijun, Schnurbusch Thorsten
Independent HEISENBERG Research Group Plant Architecture, Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany.
Research Group Image Analysis, Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany.
Front Plant Sci. 2018 Mar 15;9:330. doi: 10.3389/fpls.2018.00330. eCollection 2018.
Floret development is critical for grain setting in wheat (), but more than 50% of grain yield potential (based on the maximum number of floret primordia) is lost during the stem elongation phase (SEP, from the terminal spikelet stage to anthesis). Dynamic plant (e.g., leaf area, plant height) and floret (e.g., anther and ovary size) growth and its connection with grain yield traits (e.g., grain number and width) are not clearly understood. In this study, for the first time, we dissected the SEP into seven stages to investigate plant (first experiment) and floret (second experiment) growth in greenhouse- and field-grown wheat. In the first experiment, the values of various plant growth trait indices at different stages were generally consistent between field and greenhouse and were independent of the environment. However, at specific stages, some traits significantly differed between the two environments. In the second experiment, phenotypic and genotypic similarity analysis revealed that grain number and size corresponded closely to ovary size at anthesis, suggesting that ovary size is strongly associated with grain number and size. Moreover, principal component analysis (PCA) showed that the top six principal components PCs explained 99.13, 98.61, 98.41, 98.35, and 97.93% of the total phenotypic variation at the green anther, yellow anther, tipping, heading, and anthesis stages, respectively. The cumulative variance explained by the first PC decreased with floret growth, with the highest value detected at the green anther stage (88.8%) and the lowest at the anthesis (50.09%). Finally, ovary size at anthesis was greater in wheat accessions with early release years than in accessions with late release years, and anther/ovary size shared closer connections with grain number/size traits at the late vs. early stages of floral development. Our findings shed light on the dynamic changes in plant and floret growth-related traits in wheat and the effects of the environment on these traits.
小花发育对小麦的籽粒结实至关重要，但在茎伸长阶段（从顶小穗期到开花期），超过50%的产量潜力（基于小花原基的最大数量）会损失。目前尚不清楚动态的植株（如叶面积、株高）和小花（如花药和子房大小）生长及其与籽粒产量性状（如粒数和粒宽）之间的联系。在本研究中，我们首次将茎伸长阶段细分为七个时期，以研究温室和田间种植小麦的植株生长（第一个实验）和小花生长（第二个实验）。在第一个实验中，不同时期各种植株生长性状指标的值在田间和温室中总体一致，且不受环境影响。然而，在特定时期，两种环境下的某些性状存在显著差异。在第二个实验中，表型和基因型相似性分析表明，粒数和粒大小与开花期的子房大小密切相关，这表明子房大小与粒数和粒大小密切相关。此外，主成分分析（PCA）表明，前六个主成分分别解释了绿花药期、黄花药期、抽穗期、抽穗期和开花期总表型变异的99.13%、98.61%、98.41%、98.35%和97.93%。第一主成分解释的累积方差随着小花发育而降低，在绿花药期最高（88.8%），在开花期最低（50.09%）。最后，与晚育品种相比，早熟年份小麦品种开花期的子房大小更大，并且在花发育后期与早期相比，花药/子房大小与粒数/粒大小性状的联系更为紧密。我们的研究结果揭示了小麦植株和小花生长相关性状的动态变化以及环境对这些性状的影响。
