Fungos endofíticos das famílias Botryosphaeriaceae e Pseudofusicoccumaceae associados ao cajueiro

Abstract

The families Botryosphaeriaceae and Pseudofusicoccumaceae (Ascomycota, Botryosphaeriales) comprise species complexes that include fungi ecologically adapted to a wide range of host plants, where they are described as endophytes or latent pathogens. These fungi are known to cause diseases such as cankers, dieback, and black stem rot in various fruit crops, particularly in cashew trees. This study aimed to detect the presence of fungi from the families Botryosphaeriaceae and Pseudofusicoccumaceae in association with cashew trees, assess their endophytic nature, and determine their dissemination patterns among plants. The study began with the collection of asymptomatic cashew plants and nuts from three specific clones: CCP 76 (highly susceptible), BRS 265 (susceptible), and BRS 226 (resistant). Subsequent analyses led to the identification of fungal species belonging to the Botryosphaeriaceae and Pseudofusicoccumaceae families in different plant tissues. Pathogenicity tests were then conducted with the isolated fungi, followed by morphological and phylogenetic analyses. Based on these analyses, the endophytic isolates showed significant similarities with pathogenic species previously reported in the literature. Fungal transmission occurred both horizontally and vertically, as the presence of fungi from these families was confirmed in cashew seeds, highlighting their interaction with the plant. This study demonstrates that fungi from the Botryosphaeriaceae and Pseudofusicoccumaceae families can behave as endophytes, coexisting harmoniously with the plant. However, their pathogenic activity may be triggered under plant stress conditions, whether physiological or environmental in nature. This is the first study to identify and characterize endophytic fungi from these families in cashew trees.