Morfologia, caracterização molecular e patogenicidade de Ceratocystis fimbriata no Rio Grande do Sul

Abstract

Ceratocystia fimbriata Ellis & Halsted is a pathogen responsible for the disease wilt ceratocistis and has caused losses in many important crops in Brazil, such as Eucalyptus spp., Ficus carica, Mangifera indica, Hevea brasiliensis, Gmelina arborea and Acacia mearnsii. Ceratocystis fimbriata s.l. currently considered a "species complex" containing multiple cryptic species, many of which are not yet described. Thus, the objective of this study was to identify the species of the genus Ceratocystis associated with the disease Ceratocystis wilt in kiwi (Actinidia deliciosa) correlating morphological characteristics and phylogenetic isolates of C. fimbriata causing wilt ceratocysti in kiwifruit in Brazil with brazilian isolates from different hosts and others belonging to the clades of North America and Asia. To study whether there is host specialization, through inoculations at different eucalyptus clones and cultivars of kiwifruit, and identify eucalyptus clones and kiwi cultivars resistant. For this, samples were collected from soil and plant material of plants of kiwi with symptoms typical of the disease. To obtain the isolates, we used the method bait carrot, then immediately was obtained culture monoaspórica. Were performed phylogenetic analysis, morphological identification, mycelial growth at different temperatures, host specialization. The causal agent of wilt kiwi is C. fimbriata, which belongs to clade Latin America. The ideal temperature for development is 20-250C. It did not occur to the host specialization of C. fimbriata isolates studied. The kiwifruit cultivars are susceptible to C. fimbriata. Eucalyptus dunnii and clone 32864 were highly resistant to C. fimbriata.