Department of Crop and Forest Sciences, University of Lleida-AGROTECNIO-CERCA Center, Av. R. Roure 191, 25198 Lleida, Spain.
ICREA (Catalonian Institution for Research and Advanced Studies), Barcelona, Spain.
J Exp Bot. 2023 Jan 1;74(1):40-71. doi: 10.1093/jxb/erac410.
Identifying traits for improving sink strength is a bottleneck to increasing wheat yield. The interacting processes determining sink strength and yield potential are reviewed and visualized in a set of 'wiring diagrams', covering critical phases of development (and summarizing known underlying genetics). Using this framework, we reviewed and assembled the main traits determining sink strength and identified research gaps and potential hypotheses to be tested for achieving gains in sink strength. In pre-anthesis, grain number could be increased through: (i) enhanced spike growth associated with optimized floret development and/or a reduction in specific stem-internode lengths and (ii) improved fruiting efficiency through an accelerated rate of floret development, improved partitioning between spikes, or optimized spike cytokinin levels. In post-anthesis, grain, sink strength could be augmented through manipulation of grain size potential via ovary size and/or endosperm cell division and expansion. Prospects for improving spike vascular architecture to support all rapidly growing florets, enabling the improved flow of assimilate, are also discussed. Finally, we considered the prospects for enhancing grain weight realization in relation to genetic variation in stay-green traits as well as stem carbohydrate remobilization. The wiring diagrams provide a potential workspace for breeders and crop scientists to achieve yield gains in wheat and other field crops.
提高小麦产量的瓶颈在于确定其库强的特征。本研究通过一系列“接线图”来综述和可视化决定库强和产量潜力的相互作用过程，涵盖了发育的关键阶段（并总结了已知的潜在遗传学）。利用这一框架，我们综述并整合了决定库强的主要特征，并确定了研究空白和潜在的假说，以实现库强的增益。在开花前，通过以下方式可以增加粒数：（i）通过优化小花发育和/或减少特定茎节间长度来增强穗生长，以及（ii）通过加快小花发育速度、改善穗间分配或优化穗细胞分裂素水平来提高结实效率。在开花后，可以通过操纵子房大小和/或胚乳细胞分裂和扩张来增加籽粒库强。还讨论了改善穗脉结构以支持所有快速生长的小花，从而改善同化产物流动的前景。最后，我们考虑了与保持绿色特性以及茎碳水化合物再转移相关的遗传变异有关的提高粒重实现的前景。这些接线图为育种家和作物科学家提供了一个潜在的工作空间，以实现小麦和其他大田作物的产量增益。
