Work

Interannual Variation of Stomatal Traits Impacts the Environmental Responses of Apple Trees

Year: 2024

Type: article

Abstract: ABSTRACT Stomata are fundamental to plant‐water relations and represent promising targets to enhance crop water‐use efficiency and climate resilience. Here, we investigated stomatal density (SD) variation in 269 apple accessions across 3 years (2019–2021), which demonstrated significant differences between accessions but consistency over time. We selected 2 subsets of 20 accessions, each with contrasting SD: high stomatal density (HSD; 370–500 mm−2) and low stomatal density (LSD; 192–316 mm−2). SD groups were compared in stomatal function, leaf physiology and crop productivity across two seasons (2021–2022). LSD had lower stomatal conductance (gs) and higher intrinsic water‐use efficiency in both years (p < 0.05). Hotter and drier conditions in 2022 reduced gs similarly in both groups (−22% HSD, −21% LSD), but also created a difference in net carbon assimilation (Anet) that was not present in 2021 (HSD + 1.7 μmol CO2 m−2 s−1, p < 0.05). LSD constraints on Anet were reflected in carbon isotope discrimination (δ13C, p < 0.001) and annual decline in fruit yield (−35%, p < 0.001). Our results demonstrate the suitability of SD as a trait to improve WUE, but also identifies a trade‐off between water savings and productivity, which requires consideration for breeding.

Source: Plant Cell & Environment

DOI: 10.1111/pce.15302