Morphological differentiation across the invasive range in Senecio madagascariensis populations.

FERRUCCI, MARÍA SILVIA; DEMATTEIS, B.; COULLERI, J.P.

Scientific Reports

Nature Publishing Group

Lugar: London; Año: 2020 vol. 10 p. 1 - 8

2045-2322

Invasive species are characterized by their ability tocolonize new habitats and establish populations away from their native range.In this sense, these plants are expected to have plastic responses to adapt tothe environmental pressures during the invasion process. Hence, the role ofnatural selection is essential because it might favor the occurrence ofadvantageous traits. However, gene flow can counteract natural selectionbecause immigrants introduce genes adapted to different conditions, with theseintroductions tending to homogenize allelic frequencies. In this work, weexplore the effect of natural selection in invasive populations of S. madagascariensis in Argentina. Wequantified leaf area, head number, and length of internodes and inflorescencefrom material spanning 54 years (1962?2016) and then compared between the edgeversus established ranges. Our results show differences in all the measuredplant traits among the sampled areas. However, only leaf area was statisticallysignificant, which evidences different responses under the same environmentalpressures in the areas located in the edge and established ranges. On the otherhand, unlike homogeneous areas, the areas characterized by phenotypicallydiverse individuals were related to higher dispersal ability. In this sense,long-distance dispersal between neighboring areas may have had an important rolein the recorded values. Furthermore, the implications of natural selection andfounder effect in the invasion of S. madagascariensis are discussed.