There is considerable variation in leaf lobing and leaf size, including among grapevines, some of the most well-studied leaves. We examined the relationship between leaf lobing and leaf size across grapevine populations which varied in extent of leaf lobing. We used homologous landmarking techniques to measure 2,632 leaves across two years in 476 unique, genetically distinct grapevines from 5 biparental crosses which vary primarily in the extent of lobing. We determined to what extent leaf area could explain 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 decreases as a function of 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 a given leaf area, 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.

Leaves were sampled from seedlings of five biparental Vitis populations located in Madera County, California. Leaf samples were collected on June 22 and July 12, 2018, then again in 2019 on June 14, 19, and July 5. Across the sampling dates within a given year, a total of three mature, representative leaves were sampled from each of the vines and placed into labeled plastic bags. The plastic bags were stored in a cooler during collection and scanned, vein side down, later the same day using a flatbed scanner. Files were saved as JPEGs and named using the accession ID. 

Each seedling was a part of one of five biparental crosses. These populations included: 125 individuals from a DVIT 2876 x unnamed Vitis vinifera selection cross (Pop1), 100 individuals from a DVIT 2876 x a different unnamed Vitis vinifera selection cross (Pop2), 150 individuals from a DVIT 2876 x unnamed Vitis hybrid cross (Pop3), 75 individual from a DVIT 2876 x a different unnamed Vitis hybrid cross (Pop4), and 50 individuals from a seedling (DVIT 2876 x unnamed Vitis vinifera selection) x DVIT 3374 (Vitis mustangensis Buckley) cross (Pop5). The scan filename is the accession number, with each scan located within a subfolder labeled for the date of sampling (labeled “20180622” for 22 June 2018, “20180712” for 12 July 2018, “20190614” for 14 June 2019, “20190619” for 19 June 2019, and “20190705” for 5 July 2019. The accession names and associated population are listed in the associated metadata sheet “vitis_crosses_key.csv”. Note that leaves were not available for all accessions in both years, so some accessions may not include scans from 2018, 2019, or both. 

This is a repository of grapevine leaf scans of Vitis crosses located in Madera County, California. Leaf samples were collected on June 22 and July 12 2018, then again in 2019 on June 14, 19, and July 5. Across the sampling dates within a given year, a total of three mature, representative leaves were sampled from each of the vines. On each scan, there is a printed label indicating the name of the seedling, the position in the vineyard (row and vine number) and the year of sampling. Labels were printed in advance so the exact date of sampling listed in the scan may not be accurate, and the sub-folder which the scan is found in should be used for this information instead. The scan filename is the accession number, with each scan located within a subfolder labeled for the date of sampling. The subfolders for each of the dates are labeled as follows: “20180622” for 22 June 2018, “20180712” for 12 July 2018, “20190614” for 14 June 2019, “20190619” for 19 June 2019, and “20190705” for 5 July 2019 The accession names and associated population are listed in the associated metadata sheet “vitis_crosses_key.csv”. Note that leaves were not available for all accessions in both years, so some accessions may not include scans in 2018, 2019, or both.