Contrasting gene flow patterns and genetic subdivision in adjacent populations of Cucumis sativus ( Cucurbitaceae).

Abstract

A test of the similarity of gene migration patterns between adjacent field populations of cucumber was conducted by interplanting a block of plants with the dominant bitter gene in the center of each of two large plots of plants with the recessive allele for this marker. After natural pollination, mature fruits were mapped and then collected throughout both fields, and the seedling progeny scored for the presence of the bitter gene. The pattern of gene flow in both plots was very restricted, with most of the bitter pollen deposited within 2-3 m from the central bitter block. These and other results show that adjacent plant populations, even in homogeneous environments, can have different pollen flow dynamics, and that there can be a directional migration of alleles in a plant population without the influence of a selection pressure acting on one part of the population.-from Author