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

<b>Abstract</b><br/>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.

<b>摘要</b><br/>理论预测，自然选择会倾向于保留叶片生理学、生物化学与解剖结构之间的协调关系，使三者沿从快速资源获取型到缓慢资源保守型的功能性状谱分布。然而，这一协调假说极少在系统发育尺度下得到检验——而该尺度最有助于理解近期的快速适应，或是预测气候变化下的演化轨迹。我们通过同质园试验（common garden），对19个野生与栽培番茄类群的叶片性状间基于遗传的协调性进行了检测。研究发现，叶片结构（如比叶重（leaf mass per area））与生理功能（光合速率（photosynthetic rate）、生化能力（biochemical capacity）及CO₂扩散（CO₂ diffusion））之间仅存在较弱的整合性，尽管所有性状均沿“快-慢”谱按预测方向排布。这表明，针对新环境或作物育种的独特性状组合演化存在相当大的空间。具体而言，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，这使得植物能够在不牺牲最大光合速率的前提下提升水分利用效率（water-use efficiency）。本研究并非认为功能性状谱（如叶片经济谱（leaf economics spectrum））无关紧要，而是表明某一分类群内的诸多重要变异轴可能具有独特性，无法推广至其他类群。