Characterization of Botryosphaeriaceae species of guava and alternative control of postharvest diseases in guavas

Abstract

A major problem in the commercialization of guavas is the incidence of postharvest diseases, which coincides with the ripening of fruits. The blossom-end rots are caused by Botryosphaeriaceae species, however, accurate information about the species that occur in guava is needed, as well as data on environmental requirements for infection and the control of these pathogens. This project aims to: (i) identify the main Botryosphaeriaceae species that cause rot in guavas (ii) study the epidemiological behavior and find out what conditions are most favorable for these pathogens colonize the fruit, (iii) evaluate the effect of alternative products and thermotherapy, singly and in combination, in the control of postharvest diseases and the physicochemical characteristics of fruits. Possible Botryosphaeriaceae species will be identified based on morphological characteristics of conidia and phylogenetic studies, from the sequencing of the ITS region (Internal Transcribed Spacer) and ²-tubulin gene. The effect of temperature will be assessed on mycelial growth of the species and the effect of temperature and duration of the wetting period on conidia germination, infection and colonization of Botryosphaeriaceae species, in vitro and in vivo. The effect of postharvest treatments with calcium chloride, phosphite K, 1-methylcyclopropene, cassava starch, ethanol, sodium hypochlorite, essential oil and thermotherapy will be evaluated in the alternative management of diseases and physical-chemical characterization of guava. (AU)