South Australian Research and Development Institute, and School of Agriculture, Food and Wine, The University of Adelaide, Australia.
Proc Biol Sci. 2021 Sep 8;288(1958):20211259. doi: 10.1098/rspb.2021.1259.
Technologies, from molecular genetics to precision agriculture, are outpacing theory, which is becoming a bottleneck for crop improvement. Here, we outline theoretical insights on the wheat phenotype from the perspective of three evolutionary and ecologically important relations-mother-offspring, plant-insect and plant-plant. The correlation between yield and grain number has been misinterpreted as cause-and-effect; an evolutionary perspective shows a striking similarity between crop and fishes. Both respond to environmental variation through offspring number; seed and egg size are conserved. The offspring of annual plants and semelparous fishes, lacking parental care, are subject to mother-offspring conflict and stabilizing selection. Labile reserve carbohydrates do not fit the current model of wheat yield; they can stabilize grain size, but involve trade-offs with root growth and grain number, and are at best neutral for yield. Shifting the focus from the carbon balance to an ecological role, we suggest that labile carbohydrates may disrupt aphid osmoregulation, and thus contribute to wheat agronomic adaptation. The tight association between high yield and low competitive ability justifies the view of crop yield as a population attribute whereby the behaviour of the plant becomes subordinated within that of the population, with implications for genotyping, phenotyping and plant breeding.
从分子遗传学到精准农业，技术的发展速度超过了理论，这使得理论成为作物改良的瓶颈。在这里，我们从三个进化和生态上重要的关系——亲子关系、植物-昆虫关系和植物-植物关系的角度概述了小麦表型的理论见解。产量和粒数之间的相关性被误解为因果关系；进化视角表明，作物和鱼类之间存在惊人的相似之处。两者都通过后代数量对环境变化做出反应；种子和卵的大小是保守的。一年生植物和一次性产卵鱼类的后代缺乏亲代的照顾，因此会发生亲子冲突和稳定选择。不稳定的储备碳水化合物不符合当前的小麦产量模型；它们可以稳定粒大小，但与根生长和粒数存在权衡，对产量最多是中性的。将重点从碳平衡转移到生态作用上，我们认为，不稳定的碳水化合物可能会破坏蚜虫的渗透调节，从而有助于小麦的农业适应。高产和低竞争力之间的紧密联系证明了作物产量是一种群体属性的观点，即植物的行为在种群的行为中处于从属地位，这对基因型分析、表型分析和植物育种都有影响。
