Caracterização de isolados de Colletotrichum spp. oriundos de tomateiro

Abstract

The breaking of the resistance conferred by R genes and the emergence of strains resistant to fungicides has impaired the control of fungal diseases in agriculture. Therefore a more durable resistance is been searched, the bases of host and non-host resistence may provide solutions to this problem. Much of the basic processes of these resistence still need further research and interpretation, which is promising when employing fungal and plant models with has facilities for the use of reverse genetic techniques. Solanum lycopersicum cv. MicroTom is an excellent model for this study, because it is a representative crop in addition to exhibit the same advantages of Arabidopsis thaliana. Colletotrichum, responsible for anthracnose in many cultures, has been extensively studied and has already developed tools for reverse genetic. Thus, in order to propose the pathosystem Colletotrichum spp. - MicroTom as a model for studies of host and non-host resistance. This study tested the interaction of different species of Colletotrichum against MicroTom, Phaseolus lunatus and Musa sp. representing asteroids, rosides and monocots. First the fungal morphological characterization it was supported by rDNA sequence analyses. Enzymatic factors of pathogenicity were tested by infiltrating MicroTom`s leaves with fungal proteins secreted in liquid medium. The pathogenicity test was described by inoculation with fungal structures on S. lycopersicum, P. lunatus and Musa sp. The results suggest that C. gloeosporioides cultures 1 and 2, C. truncatum and C. musae constitute along with MicroTom excellent pathosystems for studying host and non-host resistance under different approaches. Because these isolates showed a contrasting features in the pathogenicity tests, which revealed the adaptation to Solanaceae Fabaceae and Musaceae. However detailed studies of microscopy and gene expression are needed to better characterize these types of resistance exhibited.