Fungos causadores de podridões pós-colheita em bananas e severidade da ntracnose em unidades de beneficiamento no Cariri Cearense

Abstract

Crown rot and anthracnose are important banana diseases worldwide. Currently, there is little information about the etiology of crown rot, and there is a need to accurately identify its causal agents for the development of efficient management measures. For anthracnose, several studies on the etiology and epidemiology are available. However, the behavior of this disease in the post-harvest phases of the fruit is not known. Thus, the present work aimed to identify the species of Nigrospora associated with crown rot and monitor the severity of anthracnose in bananas collected in fruit processing stages in Cariri, Ceará. To identify the species of Nigrosporas, isolates obtained from the crown of bananas with symptoms of rot, and with morphological characteristics similar to the genus, were submitted to the process of DNA extraction and sequencing of the ITS region and the TUB2 and EF1-α genes. After identification, the pathogenicity and aggressiveness of the isolates were evaluated. Based on morphological and genetic analysis, the isolates obtained belong to the species N. hainensis and N. lacticolonia. All isolates induced necrotic lesions in the inoculated fruits. This is the first report of a genetically characterized Nigrospora species associated with postharvest rot in bananas. To assess the severity of anthracnose, bananas were collected in three stages of post-harvest processing in two periods of the year. The bananas were placed in a humid chamber until the appearance of symptoms and the severity of the disease was evaluated with the aid of a diagrammatic scale. There was no significant difference between the levels of anthracnose severity between samples within the same period of the year. On the other hand, there was a significant difference in the severity levels between the periods of the year and between the post-harvest processing stages. In most situations, the severity of anthracnose was higher in the wet season. However, no pattern was found in the levels of disease severity in the different stages of processing. In Cariri Ceará, N. lacticolonia is the Nigrospora species most frequently associated with crown rot and the severity of anthracnose in the post-harvest processing stages is associated with the routines adopted in banana production areas. Keywords: Musa spp., Post-harvest rot, Packing house.