PubMed · 2026-06-23
A wild snapdragon relative that grows on nutrient-poor serpentine soils flowers earlier and produces fewer blooms under drought conditions, with wetter climates driving greater differences between soil-adapted populations. This suggests that ongoing climate drying could reduce plant reproduction and limit the beneficial exchange of genetic material between soil types.
Water limitation caused phenological delays and reduced floral displays, with drought increasing trait divergence between serpentine and non-serpentine soil populations for several reproductive traits.
In field observations, the proportion of plants actively flowering was consistently higher in wetter sites, and gene flow was directionally biased from non-serpentine toward serpentine populations.
Despite measurable phenological differences between ecotypes along the precipitation gradient, flowering time distributions overlapped substantially, suggesting gene flow across soil boundaries remains high but may decline under future drought.
