Caracteres anatómicos del segmento caulinar de 3 especies del género Opuntia en Colombia (Mondoñedo, Cundinamarca y Cañón de Chicamocha Santander)

Abstract

The Opuntia genus is recognized for its alleged phenotypic plasticity, which means that the phenotypic characteristics usually vary depending on the environmental conditions they face. In this work, anatomical characters of the caulinar segment of three species of the Opuntia genus are compared in two scenarios with climatic conditions distant; in Mondoñedo Cundinamarca, an environment characterized by humidity in the mornings and low temperatures were sampled the species O.dillenii and O.quitensis and in the chicamocha canyon that has a subxerophytic environment O.penneli and O.dilleniI, compared by manual cutting and the histological analysis in optical microscope the internal structures and tissues between the three species, in O.dilleni a comparison was made in the same species in the two zones, finding that the internal structures are more similar between the plants that share the same area Regardless of the species. The structures that confirmed and corroborated the phenotypic plasticity presenting a variation due mainly to the disposition of the water resource were the channels, mucilage cells and vascular bundles that presented greater size and development in the Mondoñedo area as well as the peridermis present only in This area as a relative humidity protection mechanism. The structures that remain unchanged for the three species are the reserve parenchyma, the cholenchymal hypodermis and the chlorophyll parenchyma mainly. The only character found that can be used for the determination of species are the sub-stomatic chambers present only in O. pennellii.