Patterns of variation in Ontario wild rice ( Zizania Aquatica L.). 3. Similarity between source and introduced populations pairs under experimental and field conditions

Abstract

Morphometric similarities between source wild rice populations and populations introduced to other sites from those sources were examined in two studies. Progeny of two populations, 5 and 50 years after introduction, were compared with progeny of the common source population over 8 water depth/fertilizer treatment combinations. In a field study, five introduced populations and their three sources were compared 5 or 10 years after establishment of the new stands. Source and introduced population pairs appeared to be genetically similar after 50 years of reproductive isolation. It is suggested that phenotypic plasticity buffers these populations from directional selection pressures, and that the degree of plasticity itself may be subject to natural selection.