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Biology subjects

Woodhouse, K.

Publications and source records attributed to Woodhouse, K..

3 recordsLinked to original sources

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

SummaryO_LIEmbedded in a single leaf shape are the latent signatures of genetic, developmental, and environmental effects. In viticulture, choice of location and rootstock are important decisions that affect the performance and production of the shoot. We hypothesize that these effects influence plant morphology, as reflected in leaf shape. C_LIO_LIWe sample 1879 leaves arising from scion and rootstock combinations from commercial vineyards in the Central Valley of California. Our design tests 20 pairwise contrasts between Cabernet Sauvignon and Chardonnay scions from San Joaquin, Merced, and Madera counties from vines grafted to Teleki 5C, 1103 Paulsen, and Freedom rootstocks. C_LIO_LIUsing geometric morphometric approaches, we visualize a morphospace in which, in addition to clear separation of Cabernet Sauvignon and Chardonnay scion leaf shapes, an orthogonal source of shape variation affects both varieties. Comparing the Procrustes distances to within and between group means, the additional source of variance is found to arise from location and rootstock effects. C_LIO_LIWe describe and visualize a specific shape feature, the angle of the proximal lobe to the midvein that defines the closure of the petiolar sinus, that is attributable to location and rootstock effects and orthogonal to and separate from genetic, developmental, or allometric effects attributable to leaf size. C_LI Societal Impact Statement (EN)The innumerable effects of terroir--including climate, soil, microbial environment, biotic interactions, and cultivation practice--collectively alter plant performance and production. A more direct agricultural intervention is grafting, in which genetically distinct shoot and root genotypes are surgically combined to create a chimera that alter shoot performance at a distance. Selection of location and rootstock are intentional decisions in viticulture to positively alter production outcomes. Here, we show that terroir and rootstock alter the shapes of grapevine leaves in commercial vineyards throughout the California Central Valley, documenting the profound effects of these agricultural interventions that alter plant morphology.

plant biology↗

Grapevine leaf size influences vine canopy temperature

PremiseGrapevine leaves have diverse shapes and sizes. Their shape and size is known to be influenced by many factors including genetics, vine phytosanitary status, environment, leaf and vine age, and node position on the shoot. In order to determine the importance of grapevine leaf shape and size to canopy temperature, we examined the relationship in five seedling populations grown in a vineyard in California, USA. MethodsAll of the populations had one parent with compound leaves of the Vitis piasezkii type and each population had a different second parent with non-compound leaves. In previous work, we measured leaf shape and size using 21 homologous landmarks. Here, we paired these morphology data with measurements taken using an infrared thermometer to measure the temperature of the canopy. By recording time of sampling and canopy temperature, we were able to determine which vines were cooler or hotter than expected, using a linear model. ResultsWe established a relationship between leaf size and canopy temperature: vines with larger leaves were cooler than expected. In contrast, leaf shape was not strongly correlated with variation in temperature. ConclusionsUltimately, these findings indicate that vines with larger leaves may contribute to the reduction of overall vine canopy temperature, but further work is needed to determine if this is due to variation in leaf size, differences in the openness of the canopy, or other related traits.

plant biology↗

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

PremiseThere 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. MethodsWe 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. ResultsAlthough 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. ConclusionsFor 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.

plant biology↗