The influences of environmental change and development on leaf shape in Vitis

Abstract

Premise The size and shape (physiognomy) of woody, dicotyledonous angiosperm leaves are correlated with climate. These relationships are the basis for multiple paleoclimate proxies. Here we test whether Vitis exhibits phenotypic plasticity and whether physiognomy varies along the vine. Methods We used Digital Leaf Physiognomy (DiLP) to measure leaf characters of four Vitis species from the USDA Germplasm Repository (Geneva, New York) from the 2012–2013 and 2014–2015 leaf‐growing seasons, which had different environmental conditions. Results Leaf shape changed allometrically through developmental stages; early stages were more linear than later stages. There were significant differences in physiognomy in the same developmental stage between the growing seasons, and species had significant differences in mean physiognomy between growing seasons. Phenotypic plasticity was defined as changes between growing seasons after controlling for developmental stage or after averaging all developmental stages. Vitis amurensis and V. riparia had the greatest phenotypic plasticity. North American species exhibited significant differences in tooth area:blade area. Intermediate developmental stages were most likely to exhibit phenotypic plasticity, and only V. amurensis exhibited phenotypic plasticity in later developmental stages. Conclusions Leaves have variable phenotypic plasticity along the vine. Environmental signal was strongest in intermediate developmental stages. This is significant for leaf physiognomic‐paleoclimate proxies because these leaves are likely the most common in leaf litter and reflect leaves primarily included in paleoclimate reconstructions. Early season and early developmental stages have the potential to be confounding factors but are unlikely to exert significant influence because of differential preservation potential.

Vein‐to‐blade ratio is an allometric indicator of leaf size and plasticity

“…Lobes and teeth might be a developmental constraint resulting from the packing of leaves in buds (Edwards et al, 2016), as is the case for grapevine. Recently, the allometry of teeth for the grapevine leaves from the 2013 and 2015 growing season described in this study was undertaken, noting their phenotypic plasticity across years, developmental context, and the meaningfulness of measuring traits used for paleoclimate reconstructions in a living germplasm collection (Baumgartner et al, 2020). The relationship between vein and blade is a fundamental feature of all leaves, an indicator of development itself that is modulated by both evolutionary and environmental forces.…”

Composite modeling of leaf shape along shoots discriminates Vitis species better than individual leaves

“…Previously, we analyzed leaf morphology across nodes in different species of Vitis and Passiflora , revealing that allometric and heteroblastic effects are statistically separable from species‐specific differences (Chitwood et al, 2016a; Chitwood and Otoni, 2017a). The tracking of alterations to leaf shape between nodes was critical for several observations, including (1) the determination that species‐specific differences in leaf shape arise from a common juvenile form (Chitwood and Otoni, 2017b) and (2) the identification of alterations to leaf morphology between growing seasons and/or years (Chitwood et al, 2016b; Baumgartner et al, 2020). In these studies, individual leaf shape was statistically analyzed, meaning that node position is a statistical effect rather than being part of the phenomenon studied (shape).…”

The shapes of wine and table grape leaves: An ampelometric study inspired by the methods of Pierre Galet

“…In these cases, subtle phenotypic features of clones are used for identification, the shape of leaves among the principal ampelographic tools available (Martínez, Boursiquot, et al, 1997; Martínez, Grenan, et al, 1997). The ability to recognize by eye or quantify genetic variation in leaf shape can be extended to development (Bryson et al., 2020; Chitwood, Klein, et al, 2016), disease (Klein et al., 2017), herbicide damage (Morton, 2019), and responses to climate change (Baumgartner, Donahoo, Chitwood, & Peppe, 2020; Chitwood et al., 2020; Chitwood, Rundell, et al, 2016). The shape of a leaf is a narrative of its history.…”