Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Comparative cytogenetic and morpho-anatomical study among diploids and polyploids of Solanum elaeagnifolium (Solanaceae).

Abstract

Background and aims: Solanum elaeagnifolium, morphologically variable, multiplies sexually and asexually and is invasive worldwide. In Argentina there are natural diploid, tetraploid and hexaploid populations. It presents three clearly separated genetic lineages, two in South America with polyploid populations and a third with only diploids in North America and invaded areas. Our aim is to detect relationships among ploidy levels, lineages and provenance with morphological features of the plants and climatic variables.M&M: Chromosomal preparations and measurements of epidermal, floral and seed features were made in 2x, 4x and 6x individuals from different lineages and geographic origin. The mean values obtained were compared by statistical tests and the global similarity assessed by multivariate analyses. Results: Only number of stomata and seed mass were significantly different between ploidy levels: the tetraploids have fewer stomata and heavier seeds. The remaining morphoanatomical variables contribute to the global differentiation of cytotypes, although the means did not vary proportionally with increasing ploidy. Mean annual rainfall contributes to the separation of cytotypes, the western distribution of tetraploids coinciding with the arid diagonal in Argentina. Conclusions: The differences in the tetraploids cannot be attributed to a polyploidization effect. The global pattern of data could be explained by multiple independent origins of polyploidy, phenotypic plasticity, and environmental pressures.