Characterisation of pseudogamous apospory in the reproductive biology of the invasive weed Rubus alceifolius (Rosaceae) in its area of introduction

Abstract

A previous study on reproductive biology of Rubus alceifolius showed that this invasive weed reproduces asexually via apomixis, with however a residual sexuality, in the Indian Ocean islands where it has been introduced, whereas it reproduces only sexually in its South-eastern Asian native range. To determine which type of apomixis occurs in the area of introduction, we performed hand-pollinations on flowers of individuals from La Réunion island to test whether pollination is necessary for seed set. exhibit evidence of pollination by showing three nuclei. Pollination was found to be necessary for seed set, cells clearly exhibit three nuclei, showing that fertilisation took place. These data strongly suggest that R. alceifolius reproduces by pseudogamous apospory in its area of introduction. By preserving and multiplying a single well-adapted genotype, this trait may contribute to the invasiveness of it where it was introduced.