First report of Clonostachys rosea associated with avocado fruit rot in Puebla, Mexico

Abstract

The northern highlands of Puebla are considered a new potential area for the cultivation of Hass avocado. Then, the emergence of new phytopathogens related to this geographical area is latent. The aim of this investigation was to isolate the microorganisms linked to the avocado fruit rot recently recorded by the producers of this locality in 2021. The fungus associated with the avocado fruit rot was isolated under humidity chamber conditions and it was named as C08-9. The fungal agent presented white cotton mycelium with fast radial growth (6.5 mm day-1) in potato dextrose agar and it turned the culture medium to yellow color after seven days. The fungus contained penicillate conidiophores adhered to hyaline hyphae organized in whorls with three or four phialides whereas primary conidia showed oval to sub-oval shape. The average size of the conidia was 10.57 µm × 4.42 µm and the presence of chlamydospores was also recorded. The molecular identification of the fungus was achieved by amplifying the partial nucleotide sequences of the 18S ribosomal gene (ITS; 543 bp) and the translation elongation factor 1 alpha gene (TEF-1?; 658 bp). The corresponding sequences were deposited at the NCBI-gene bank with the accessions OM473286 and OM715999, respectively.