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sur le développement des zones arides et semi-arides

Titre : Estudio de la diversidad de organismos fotosintéticos en biocostras de suelos desérticos de San Luis Potosí

Auteur : Torres Bárcenas, Nohemí Vanesa

Etablissement de soutenance : Instituto Potosino de Investigación Científica y Tecnológica (IPICYT)

Grade : Maestra en Ciencias en Biología Molecular 2021

Résumé
The biocrusts are communities composed by microorganisms such as cyanobacteria, heterotrophic bacteria, chlorophytes, fungi, and macroscopic organisms like lichens, bryophytes, and microarthropods. They are mainly distributed in desert ecosystems. In the state of San Luis Potosí, the knowledge of photosynthetic organisms in biocrusts is rather limited. For this reason, the present work aimed at the identification of photosynthetic organisms and microorganisms present in biocrust of desert soils in the surroundings of two the localities Armadillo de los Infante and Guadalcázar. The methodologies in this study included molecular biology techniques, as well as microscopy. In this context, the diversity of lichens was recorded in the study sites, where Psora icterica, Psora crenata, and the genera Diploschistes sp. and Placidium sp., were found. Furthermore, the presence of chlorophytes, some microorganisms of the genera Myrmecia sp. and Trebouxia sp., the latter of these was also observed as a free-living chlorophyte. Finally, other microorganisms observed in soil samples associated with the biocrusts were the heterocystic cyanobacteria of the genera Scytonema sp., Nostoc sp., and Stigonema sp., as well as the non-heterocystic cyanobacteria of the genera Phormidium sp., and Oscillatoria sp. Therefore, in the present study it was possible to identify species of lichens, microalgae and soil cyanobacteria, similar to those reported in other biocrusts studies carried out in Mexico and other parts of the world. The species identified in the study locations correspond to common species in arid and semi-arid environments, according to various author

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