Morphological diferentiation across the invasive range in Senecio madagascariensis populations

DEMATTEIS BRUNO; MARIA SILVIA FERRUCCI; JUAN PABLO COULLERI

Scientific Reports

Nature Research

Lugar: Nueva Yori; Año: 2020 vol. 10

Invasive species are characterized by their ability to colonize new habitats and establish populations away from their native range. In this sense, these plants are expected to have plastic responses to adapt to the environmental pressures during the invasion process. Hence, the role of natural selection is essential because it might favor the occurrence of advantageous traits. However, gene flow can counteract natural selection because immigrants introduce genes adapted to diferent conditions, with these introductions tending to homogenize allelic frequencies. In this work, we explore the efect of natural selection in invasive populations of S. madagascariensis in Argentina. We quantifed leaf area, head number, and length of internodes and inforescence from material spanning 54 years (1962?2016) and then compared between the edge versus established ranges. Our results show diferences in all the measured plant traits among the sampled areas. However, only leaf area was statistically signifcant, which evidences diferent responses under the same environmental pressures in the areas located in the edge and established ranges. On the other hand, unlike homogeneous areas, the areas characterized by phenotypically diverse individuals were related to higher dispersal ability. In this sense, long-distance dispersal between neighboring areas may have had an important role in the recorded values. Furthermore, the implications of natural selection and founder efect in the invasion of S. madagascariensis are discussed.