Plant Genome Mapping Laboratory, University of Georgia, Athens, Georgia, United States of America.
Department of Statistics, University of Georgia, Athens, Georgia, United States of America.
PLoS One. 2021 Aug 13;16(8):e0255922. doi: 10.1371/journal.pone.0255922. eCollection 2021.
Tillering and secondary branching are two plastic traits with high agronomic importance, especially in terms of the ability of plants to adapt to changing environments. We describe a quantitative trait analysis of tillering and secondary branching in two novel BC1F2 populations totaling 246 genotypes derived from backcrossing two Sorghum bicolor x S. halepense F1 plants to a tetraploidized S. bicolor. A two-year, two-environment phenotypic evaluation in Bogart, GA and Salina, KS permitted us to identify major effect and environment specific QTLs. Significant correlation between tillering and secondary branching followed by discovery of overlapping sets of QTLs continue to support the developmental relationship between these two organs and suggest the possibility of pleiotropy. Comparisons with two other populations sharing S. bicolor BTx623 as a common parent but sampling the breadth of the Sorghum genus, increase confidence in QTL detected for these two plastic traits and provide insight into the evolution of morphological diversity in the Eusorghum clade. Correspondence between flowering time and vegetative branching supports other evidence in suggesting a pleiotropic effect of flowering genes. We propose a model to predict biomass weight from plant architecture related traits, quantifying contribution of each trait to biomass and providing guidance for future breeding experiments.
分蘖和次生分枝是两个具有高度农艺重要性的可塑性特征，特别是在植物适应不断变化的环境的能力方面。我们描述了两个新的 BC1F2 群体的分蘖和次生分枝的数量性状分析，这两个群体共有 246 个基因型，是通过将两个 Sorghum bicolor x S. halepense F1 植物回交四倍体化的 S. bicolor 得到的。在乔治亚州的 Bogart 和堪萨斯州的 Salina 进行了为期两年的两环境表型评估，使我们能够鉴定出主要效应和特定环境的 QTL。分蘖和次生分枝之间存在显著相关性，随后发现了重叠的 QTL 集，这仍然支持这两个器官之间的发育关系，并表明存在多效性的可能性。与另外两个群体的比较，这些群体都以 S. bicolor BTx623 作为共同亲本，但采样范围更广，这增加了对这两个可塑性特征的 QTL 检测的可信度，并为 Eusorghum 分支中形态多样性的进化提供了深入了解。开花时间和营养分枝之间的对应关系支持了其他证据，表明开花基因具有多效性效应。我们提出了一个从与植物结构相关的性状预测生物量重量的模型，量化了每个性状对生物量的贡献，并为未来的育种实验提供了指导。
