Postharvest fruit rot on red guava caused by Neopestalotiopsis saprophytica newly reported in Hainan Province China

Red Guava is widely grown in numerous parts of southern China and is a favorite fruit among Chinese consumers due to its imperative nutritional value, high medicine value and excellent economic value. Black spot is one of the serious diseases that causes fruits rot. In July 2023, 25-30% of postharvest red guava fruits rot exhibiting disease symptoms were observed in surrounding markets of Haikou city, Hainan province, China. The purpose of this study was to isolate and identify the pathogenic fungi of red guava black spot. A total of 26 pathogenic fungal strains were isolated from the rotten red guava fruits with typical characteristics. One representative isolate, FSL2, was selected for subsequent experiments. Combining morphological analysis with phylogenetic analysis (internal transcribed spacer regions 4 and 5, translation elongation factor1, and beta-tubulin genes), the pathogens should be identified as Neopestalotiopsis saprophytica. Pathogenic tests indicated that the symptoms of red guava fruit decay caused by N. saprophytica isolated from the sample were almost the same. The fungal species has been previously reported in China on Persimmon related with fruits rot. Thus, this study concluded that the pathogen of red guava black spot may be N. saprophytica. To best of our knowledge, this is the first report of red guava black spot caused by N. saprophytica.