Morfologia, variabilidade genética e patogenicidade de Ceratocystis fimbriata em Hevea brasiliensis

• Autor(a) principal: Valdetaro, Denise Cristina de Oliveira Franco
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4410
• topic: Mofo cinzento; Seringueira; Microssatélites; ITS; Gray mold; Rubber tree; Microssatellite; ITS; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOSSANIDADE::FITOPATOLOGIA

Ceratocystis fimbriata sensu lato (s.l.) is a complex of many species that are important pathogens of a large number of woody and herbaceous plants. One of this hosts is rubber tree (Hevea sp.), that is native to the Amazon and belong to the family Euphorbiacea. Rubber tree is grown in order to produce latex, the main raw material for obtaining natural rubber that is used in many different industries. Ceratocystis fimbriata infects the rubber tree panel, causing gray mold that affects latex production. C. fimbriata is considered now as a "species complex" containing cryptic species, and many of them remain undescribed. Thus, the aim of this work was to determine the morphology and phylogenetic relationships of the fungus that causes gray mold in rubber tree in order to confirm whether it is a new species of fimbriata complex. For this, it was used 20 isolates obtained from rubber tree for analysis of genetic variability. Of these, four isolates were selected for morphological and phylogenetic analysis and of those, two isolates were used for pathogenicity tests. According to the sequences of ITS r-DNA, the isolates of C. fimbriata of rubber tree belong to the Latin American clade, with two ITS genotypes, that is related to their geographical origin. One genotype was originated from the state of Acre and the other one from the state of Bahia, which was also confirmed by microsatellite markers. The inoculations showed no specialization to the host, since they were pathogenic to different host species (mango, crotalaria, acacia, eucalyptus and kiwi). Therefore, according to the results of this work, the isolates of rubber tree belong to the Latin American clade and confirmed as C. fimbriata and not a distinct species.