Multilocus phylogenetic analyses suggest the presence of Colletotrichum chrysophilum causing banana anthracnose in Mexico

Abstract

Postharvest anthracnose disease caused by Colletotrichum species is one of the main threats to banana production because it reduces the quality, the marketability, and the consumption of the fruit. From June to September 2017, coalescent sunken necrotic lesions were observed on the banana fruit cv. Tabasco (Musa acuminata), harvested in two orchards in Teapa, Tabasco, southeast of Mexico. Thus, this research aimed to identify the causal agents of necrotic lesions that affect banana production. Isolates of Colletotrichum spp. obtained from the sunken necrotic lesions were studied by morphological and multilocus phylogenetic approaches. Amplification and sequencing of the six (GAPDH, CHS-1, ACT, TUB, GS, and APMAT) partial genes were performed. Later, individual alignment for each gene was created and concatenated. Bayesian inference and maximum likelihood analyses revealed that the three representative strains belong to C. chrysophilum, a member of C. gloeosporioides species complex. To determine whether C. chrysophilum strains were responsible for the symptoms on banana fruit, a pathogenicity test was conducted by inoculation of wounded fruit. Typical necrotic lesions were observed 8 days after inoculation, while the control fruit remained healthy. This finding represents the first report of C. chrysophilum causing anthracnose of banana in Mexico; therefore, it should be considered an integrated management program to reduce losses caused by this disease.