Increases in vein length compensate for leaf area lost to lobing in grapevine

Abstract

Premise 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. Methods 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. Results 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. Conclusions 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.

Terroir and rootstock effects on leaf shape in California Central Valley vineyards

“…To determine if this represented an allometric effect related to leaf area, we modeled vein-to-blade ratio (as a proxy of leaf size for normalized leaves) as a function of each PC1 value from Figure 6A or Figure 6B using eigenleaf representations from the inverse transform ( Figure 6C ). Cabernet Sauvignon values are higher than Chardonnay as expected for a deeply lobed leaf (Migicovsky et al, 2022) and show a marginally positive relationship between PC1 values and vein-to-blade ratio, but Chardonnay does not. The range of vein-to-blade ratios across PC1 values of the PCA of leaf differences is 0.045 to 0.080 ( Figure 6C ), only a fraction of the vein-to-blade ratios observed for actual leaves (0.025 to 0.125, Figure 2F ).…”

Intra‐leaf modeling of Cannabis leaflet shape produces leaf models that predict genetic and developmental identities

“…Morton, 1979) relied heavily on leaf shape to distinguish grapevine varieties. Unlike Cannabis, grapevine leaves have a consistent number of lobes, sinuses, and other associated homologous points that can be used for both landmark-based and EFD morphometric analysis (Chitwood et al, 2014;Chitwood, 2021) to disentangle genetic (Demmings et al, 2019), developmental (Chitwood et al, 2016a;Bryson et al, 2020;Migicovsky et al, 2022), and environmental effects (Chitwood et al, 2016b(Chitwood et al, , 2021 embedded in leaf shapes.…”

Intra-leaf modeling ofCannabisleaflet shape produces leaf models that predict genetic and developmental identities

“…Morton, 1979) relied heavily on leaf shape to distinguish grapevine varieties. Unlike Cannabis, grapevine leaves have a consistent number of lobes, sinuses, and other associated homologous points that can be used for both landmark-based and EFD morphometric analysis (Chitwood et al ., 2014; Chitwood, 2021) to disentangle genetic (Demmings et al ., 2019), developmental (Chitwood et al ., 2016a; Bryson et al ., 2020; Migicovsky et al ., 2022), and environmental effects (Chitwood et al ., 2016b, 2021) embedded in leaf shapes.…”

“…Morton, 1979) relied heavily on leaf shape to distinguish grapevine varieties, which like Cannabis, is a culturally popular plant used for psychoactive, recreational purposes with a charismatic leaf shape. Unlike Cannabis, grapevine leaves have a consistent number of lobes, sinuses, and other associated homologous points that can be used for both landmark-based and EFD morphometric analysis (Chitwood et al, 2014;Chitwood, 2021) to disentangle genetic (Demmings et al, 2019), developmental (Chitwood et al, 2016a;Bryson et al, 2020;Migicovsky et al, 2022), and environmental effects (Chitwood et al, 2016b(Chitwood et al, , 2021 embedded in leaf shapes. The variable number of leaflets in Cannabis leaves precludes analysis methods that rely on homologous, comparable points to measure shape comprehensively.…”