Macromorphological variation of the invasive Silverleaf nightshade (Solanum elaeagnifolium Cav.) and its relation to climate and altitude in Morocco
The relationship between some morphological traits and the invasive potential of invasive alien plants has been reported. Also, biological invasion is often associated with rapid evolution in introduced species. The study aim was to provide the structure of morphological variation of the invasive Solanum elaeagnifolium and to assess if the invasion of Morocco was followed by a rapid evolution that may affect its invasive potential. A total of 709 individuals from 218 sites, sampled across different ecological conditions, were characterized for 12 variables. The structure of the morphological variation by Hierarchical Cluster Analysis and Linear Discriminant Analysis has determined four morphotypes. Traits related to the total number of shoots and berries are those that discriminate the most between morphotypes. The description of the four morphotypes implied a rapid evolution in this species in Morocco. This evolution has resulted in large plants with a very high number of berries. However, the smallest morphotype is still predominating and is the most invasive. The geographical distribution of the four morphotypes indicates that S. elaeagnifolium tended to be an r-strategist plant, especially in the most severe ecological conditions. This strategy allows S. elaeagnifolium to allocate most of the energy to reproduction and therefore become more invasive.
Keywords: Solanum elaeagnifolium, morphology traits, invasive potential, morphotypes, ecological factors.