Diversidade fenotípica e genotípica de isolados de Pisolithus spp.

Abstract

Pisolithus spp. is a cosmopolitan fungus living in symbiosis with a numberof tree species, mainlyEucalyptus and Pinus. Isolates from Brazil, USA and Canadá were used for the evaluation of the phenotypic and genotypic diversity of Pisolithus spp. Morphological, biochemical (PAGE and SDSPAGE) and molecular (RAPD) markers were analysed for the identification of potential genotypes with broad genetic base that could be used in programs aiming the improvement of the ectomycorrhizal symbiosis. It was possible to group the isolates on the basis of morphological and molecular markers. The divergence rate for morphological markers ranged from 0 to 82%, whereas for protein ranged from 9 to 80% and for enzyme from 0 to 79%. The crosses apt to broaden the genetic base for morphological markers were P4 x P21 and P4 x P25, whereas for proteins were PIO x P31, PI3 x P29, PI3 x P30, PI8 x P29 and P20 x P3I, and enzymes were PI3 x PI8 and PI5 x P33. The distintion of the isolates in relation to their colonization to the host was mad possible by comparative analysis of the groups obtained throught the different molecular markers. RAPD was the most indicated marker for evaluation of diversity, considering that it was no influenced by the cultivation conditions, having a direct link with the genetic material.