Repositori URV

Identificador: TDX:526

Handle: https://hdl.handle.net/20.500.11797/TDX526

Autors:
García Sánchez, Dania

Resum:
In the last 20 years the compounds obtained from fungi were increased up to 77%, and main of these species of fungi which producing new metabolites were isolated from soil. The first step in the investigation of substances biologically active produced by fungi is collects a profuse diversity of these organisms, their isolation, classification and conservation. The soil is one of the major reservoir of fungal propagules; but soil ascomycetes may remain in dormant spores phase, so is necessary the disruptions of this stage to obtain pure cultures. Therefore one of our main objectives was to use different activation techniques of dormant ascospores. In other hand, classification of the ascomycetes has been traditionally based on morphological criteria. However, numerous recent studies have demonstrated that a taxonomic classification based only on morphological characters frequently does not correlate with the phylogenetic relationships inferred from DNA sequences. In this way the mains aims of this study was to evaluate the morphological and genetic relationships between Gelasinospora and Neurospora and also to delimitate the relationships among the genera recognized in the family Coniochaetaceae.In this work more than 1500 soil samples were analyzed. The methods selected for the activation of the dormant ascospores were those based on the action of acetic acid, ethanol and phenol. Through the activation by the action of phenol and by ethanol five new taxa were isolated: · Apiosordaria globosa, · Apiosordaria hispanica,· Neurospora nigeriensis, · Neurospora uniporata and· Poroconiochaeta tetraspora.The application of soil bait technique (indirect isolation method) using a dry wood fragment like bait, allowed to us to described five new taxa; the new genus Coronatomyces an