Abscission, the programmed shedding of plant organs, is an essential part of tree development and reproduction, but much firm scientific details of the process have mostly been extrapolated from model plants such as Arabidopsis and therefore does not explain how long-lived woody plants coordinate flower loss, fruit retention, and resource allocation under real reproductive pressures.
In Prunus, abundant flowering increases the chance of fertilisation, but trees cannot mature every flower into fruit because nutrient supply and developmental capacity are limited. Earlier studies mainly examined fruit detachment, so that the timing and function of earlier floral shedding was less well understood.
Now researchers from Seoul National University have reported work on Prunus × yedoensis and Prunus sargentii to regulate reproduction through a hierarchical abscission program in which petals, calyces, flower pedicels, fruit pedicels, and peduncles are shed in sequence to refine final fruit set.
The team tracked five abscission events across reproduction and showed that they occur in a fixed order: petal, flower pedicel-peduncle (flower PP), calyx, fruit PP, and peduncle-branch abscission. In P. × yedoensis, petals dropped rapidly after flowering even without pollination, showing that this first step follows an internal developmental timer rather than successful fertilization. In contrast, P. sargentii often retained petals on unfertilized flowers, and those flowers were later discarded whole through flower PP abscission, potentially extending the window for pollination.
The study also confirmed that fruit selection continued after fertilization. In P. × yedoensis, fruit PP abscission removed many small, slow-growing fruits; abscised fruits were much smaller than retained ones, and their seeds were only about 16.7 per cent the size of seeds in retained fruits. Mechanistically, the process involved localized ethylene responsiveness, reactive oxygen species, pH shifts, and in some tissues, lignin deposition, while the calyx abscission zone formed de novo rather than being pre-formed like other zones.
The findings suggest that cherry trees are continuously evaluating reproductive success and developmental quality. By using sequential checkpoints, the plants can remove unfertilised flowers early, discard weak fruits later, and align reproductive output with what the tree can actually support. This makes abscission not just a structural process, but a dynamic reproductive filter that helps woody perennials balance opportunity with restraint under fluctuating pollination and resource conditions.
In turn, this offers a broader framework for understanding how perennial fruit-bearing plants manage reproductive investment. It may help researchers and breeders think differently about fruit set, yield stability, and stress responses in cherries and related crops.