Data from: Weak coordination between leaf structure and function among closely related tomato species

Theory predicts that natural selection should favor coordination between leaf physiology, biochemistry and anatomical structure along a functional trait spectrum from fast, resource-acquisitive syndromes to slow, resource-conservative syndromes. However, the coordination hypothesis has rarely been tested at a phylogenetic scale most relevant for understanding rapid adaptation in the recent past or for the prediction of evolutionary trajectories in response to climate change. We used a common garden to examine genetically based coordination between leaf traits across 19 wild and cultivated tomato taxa. We found weak integration between leaf structure (e.g. leaf mass per area) and physiological function (photosynthetic rate, biochemical capacity and CO2 diffusion), even though all were arrayed in the predicted direction along a ‘fast–slow’ spectrum. This suggests considerable scope for unique trait combinations to evolve in response to new environments or in crop breeding. In particular, we found that partially independent variation in stomatal and mesophyll conductance may allow a plant to improve water-use efficiency without necessarily sacrificing maximum photosynthetic rates. Our study does not imply that functional trait spectra, such as the leaf economics spectrum, are unimportant, but that many important axes of variation within a taxonomic group may be unique and not generalizable to other taxa.理论预测，自然选择会沿从快速资源获取型策略到缓慢资源保守型策略的功能性状谱，推动叶片生理学、生物化学与解剖结构间形成协同适配关系。然而，这一协调假说极少在与理解近期快速适应性、或预测气候变化下演化轨迹最为相关的系统发育尺度上得到检验。我们通过同质园（common garden）实验，探究了19个野生与栽培番茄类群的叶片性状间基于遗传的协调关系。我们发现，尽管叶片结构（如比叶重（leaf mass per area））与生理功能（光合速率（photosynthetic rate）、生化容量（biochemical capacity）及二氧化碳扩散（CO2 diffusion））之间仅存在较弱的整合性，但所有性状均沿预测的“快-慢”谱线分布。这表明，在应对新环境或开展作物育种时，演化出独特性状组合的空间相当可观。尤为值得注意的是，我们发现气孔导度（stomatal conductance）与叶肉导度（mesophyll conductance）存在部分独立的变异，这使得植物能够在无需牺牲最大光合速率的前提下提升水分利用效率（water-use efficiency）。本研究并非意指功能性状谱（如叶片经济谱（leaf economics spectrum））无关紧要，而是表明某一分类群内诸多重要的变异轴可能具有独特性，无法推广至其他类群。