Plant, Food, and Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia, Canada, B2N 5E3.
Department of Biology, Saint Louis University, St. Louis, MO, 63103-2010, USA.
Am J Bot. 2022 Jul;109(7):1063-1073. doi: 10.1002/ajb2.16033. Epub 2022 Jul 19.
Leaf lobing and leaf size vary considerably across and within species, including among grapevines (Vitis spp.), some of the best-studied leaves. We examined the relationship between leaf lobing and leaf area across grapevine populations that varied in extent of leaf lobing.
We used homologous landmarking techniques to measure 2632 leaves across 2 years in 476 unique, genetically distinct grapevines from five biparental crosses that vary primarily in the extent of lobing. We determined to what extent leaf area explained variation in lobing, vein length, and vein to blade ratio.
Although lobing was the primary source of variation in shape across the leaves we measured, leaf area varied only slightly as a function of lobing. Rather, leaf area increases as a function of total major vein length, total branching vein length, and vein to blade ratio. These relationships are stronger for more highly lobed leaves, with the residuals for each model differing as a function of distal lobing.
For leaves with different extents of lobing but the same area, the more highly lobed leaves have longer veins and higher vein to blade ratios, allowing them to maintain similar leaf areas despite increased lobing. These findings show how more highly lobed leaves may compensate for what would otherwise result in a reduced leaf area, allowing for increased photosynthetic capacity through similar leaf size.
叶片裂叶和叶片大小在物种间和种内差异很大，包括在葡萄属（Vitis spp.）中，葡萄属的叶片是研究最多的叶片之一。我们研究了裂叶程度不同的葡萄种群中叶片裂叶和叶面积之间的关系。
我们使用同源标志点技术，在 5 个双亲杂交中，476 个具有独特遗传背景的葡萄树上，连续 2 年测量了 2632 片叶子，这些杂交种主要在裂叶程度上有所不同。我们确定了叶面积在多大程度上解释了裂叶、叶脉长度和叶脉与叶片的比例的变化。
虽然裂叶是我们所测量的叶片形状变化的主要来源，但叶面积的变化与裂叶几乎没有关系。相反，叶面积随着总主叶脉长度、总分枝叶脉长度和叶脉与叶片的比例的增加而增加。这些关系在裂叶程度较高的叶片中更为明显，每个模型的残差随着远侧裂叶的不同而不同。
对于具有不同裂叶程度但面积相同的叶片，裂叶程度较高的叶片具有更长的叶脉和更高的叶脉与叶片的比例，使它们能够在裂叶增加的情况下保持相似的叶面积。这些发现表明，裂叶程度较高的叶片如何通过类似的叶片大小来补偿否则会导致叶面积减少的情况，从而增加光合作用能力。
