Contemporary pollen flow, characterization of the maternal ecological neighbourhood and mating patterns in wild cherry (Prunus avium L.)

Conversion of lowland woodland to agricultural land and resulting fragmentation in Britain has been ongoing since Neolithic times. To counteract this decline, plantations of native species, often based on non-British planting stock, have been established. This may ultimately be detrimental to the integrity of the native gene pool. We explore the genetic and ecological factors influencing the success of components of the local pollen pool, including the effect of a non-native planting on an ancient woodland population of wild cherry. Wild cherry exhibits gametophytic self-incompatibility (GSI) and vegetative reproduction, both of which may be determinants of paternal success. The majority (61%) of the successful pollen originated from within the study site with a maximum pollen transfer distance of 694 m. There was a distinct departure from random mating, with over half the successful pollen originating from trees which occur within 100 m of the mother tree. Self-incompatibility, clonality, tree size and proximity to the mother tree were all found to influence paternal success. Kinship of pollen gametes within a maternal progeny was highest when a mother tree was surrounded by a large number of ramets of a single, compatible clone consisting of large, adult trees. Although the contribution from the non-native plantation is currently low, it is likely that this will increasingly contribute to the progeny of the adjacent ancient population as it matures. The results clearly show that in self-incompatible species, such as P. avium, close neighbours may be pollinated by very different components of the local pollen pool.