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Characterization and molecular, morpho-cultural, physiological and pathogenic identification of Colletotrichum spp. of rubber tree and induction of resistance of rubber tree to this fungus using saprobic organisms of the northeastern semiarid

Abstract

The rubber tree (Hevea brasiliensis Müell. Arg.) Is a species native to the Amazon region, widely cultivated in Brazil. With the expansion of planted areas of this crop, many diseases that previously were not expressive gain importance, such as anthracnose, caused by fungi of the genus Colletotrichum, which attacks leaves, causing premature fall of these. Thus, studies aimed at determining which Colletotrichum species occur and which prevail in the main rubber producing regions and which characterize the populations of the pathogen are important for the country. This work aims to identify and characterize Colletotrichum species associated with rubber tree anthracnose in different Brazilian States. For this, phylogenetic analyzes using partial sequences of the ITS, TUB2, CAL, CHS-1 and GAPDH genes will be performed, as well as evaluations of the morphological characteristics of conidia and apressoris and the cultural and physiological characteristics of colonies grown at different temperatures. The isolates will also be characterized pathogenically by inoculation in different rubber clones. Allied to the experiment of differential reaction of clones will be carried out tests of induction of resistance of rubber tree to Colletotrichum using saprobic fungi of the northeastern semiarid, identified by BIOTA project of 2012. Finally, representative isolates of the main species found will be evaluated for the percentage of germinated conidia and Appressors formed during the pre-penetration phase in rubber leaflets, under the influence of different temperatures and periods of wetting. The results obtained will allow a better understanding of the etiological and epidemiological aspects of the disease, providing subsidies for the development and adoption of adequate control methods for Colletotrichum species associated with rubber tree anthracnose in Brazil. (AU)