Genetic and environmental factors affecting reproductive variation in Allium vineale

Abstract

Traits related to allocation of resources to sexual and asexual reproduction, together with seed production, were scored on Allium vineale plants sampled from five sites in southern Sweden during a period of 4 years. In addition, random amplified polymorphic DNA (RAPD) fingerprinting of the sampled plants allowed the identification of genets. Integration of genetic and phenotypic data from field and greenhouse provided for the analysis of among-year, among-site, and among-genet variance components. These variance components were taken to represent the influences of short-term environmental changes, persistent site divergence, and within-site genet differences, respectively. It was shown that differences among sites and among genets explained a large part of the phenotypic variation of allocation traits, whereas among-year differences had a larger influence on the variation in seed production. Together, the results support the conclusions of a recent model on the evolution of mixed reproductive systems, that predicts a stable balance between sexual and asexual reproduction because of annual fluctuations in fecundity through the two modes.