Phenotypic adaptations, anatomical characterization and ecological niche modeling for Melinis minutiflora P. Beauv.

Abstract

Phenotypic characteristics, especially phenotypic plasticity, have been constantly proposed as a key contributor to the successful invasion of introduced plants. At the same time, environmental conditions are also important in increasing the survival rate in the initial introduction phase. In this context, the aim of the work was to evaluate the physiological, morphological, and anatomical characteristics of the invasive species Melinis minutiflora in locations with different environmental conditions and at different altitudes; as well as to develop a model for M. minutiflora in current and future climates (2050, 2070, 2100) using CLIMEX and to identify the most sensitive climate parameters using sensitivity analysis. Three projects were carried out. The first was carried out in a growth room and a greenhouse, with ten replicates. Chlorophyll a and b, chlorophyll a fluorescence, height, number of tillers and leaves and dry mass of the aerial part and root were evaluated. In the second, the treatments represented by the five sampling sites in conservation units corresponded to altitudes of 157, 723, 996, 1477 and 1573 meters. Paradermal and transversal anatomical sections were made in the leaves of M. minutiflora. Stomatal density (SD), trichome density (Tr.Tec), stomatal index (SI), stomatal functionality (SF), leaf blade thickness (LB), and epidermis thickness (Ep) were evaluated. In the third, the CLIMEX model was used to model the distribution of M. minutiflora. The dry mass of the aerial part of M. minutiflora was higher in the growth room (SC2). Stomatal density was higher at high altitude, while adaxial and abaxial trichome density increased at low altitude. Melinis minutiflora has phenotypic plasticity at physiological, morphological and anatomical levels. Ecological niche modeling is a suitable tool to indicate potential areas for invasive plant establishment in future climate change scenarios. In the future climate scenarios 2050, 2070, and 2100 M. minutiflora will change its distribution, migrating to higher latitudes and altitudes as temperatures increase.