Draft genome assembly of Colletotrichum musae, the pathogen of banana fruit.

Colletotrichum musae is an important cosmopolitan pathogenic fungus that causes anthracnose in banana fruit. The entire genome of C. musae isolate GM20 (CMM 4420), originally isolated from infected banana fruit from Alagoas State, Brazil, was sequenced and annotated. The pathogen genomic DNA was sequenced on HiSeq Illumina platform. The C. musae GM20 genome has 50,635,197 bp with G + C content of 53.74% and in its present assembly has 2763 scaffolds, harboring 13,451 putative genes with an average length of 1626 bp. Gene prediction and annotation was performed by Funannotate pipeline, using a pattern for gene identification based on BUSCO.

Thiophanate-Methyl Resistance and Fitness Components of Colletotrichum musae Isolates from Banana in Brazil.

Anthracnose, caused by Colletotrichum musae, is the most important postharvest disease of banana and is widely distributed among the banana production regions in Brazil. Although thiophanate-methyl is a fungicide frequently used in Brazilian banana orchards to control Sigatoka leaf spot, Collettotrichum populations are also exposed, resulting in the evolution of fungicide resistance and the inability to manage banana anthracnose. We investigated 139 Brazilian isolates of C. musae for thiophanate-methyl sensitivity in vitro. The 50% mycelial growth inhibition (EC50) values varied between 0.003 and 48.73 µg/ml. One-hundred and thirty isolates were classified as sensitive, with EC50 values ranging from 0.003 to 4.84 µg/ml, while the remaining nine isolates were considered moderately resistant, with EC50 values ranging between 10.43 and 48.73 µg/ml. Resistant or highly resistant isolates (EC50 > 100 µg/ml) were not found. A substitution of TAC for TTC at codon 200 in a coding region of the ß-tubulin gene was associated with the moderately resistant phenotype. Applications of thiophanate-methyl formulation to detached banana fruit at the label rate (500 µg/ml) showed low efficacy in controlling the moderately resistant isolates on banana fruits. However, there is no indication of a reduction in fitness associated with fungicide resistance as sensitive and moderately resistant isolates do not differ with respect to mycelial growth rate (P = 0.098), spore production (P = 0.066), spore germination (P = 0.366), osmotic sensitivity (P = 0.051), and virulence (P = 0.057). Our results revealed absence of adaptability cost for the moderately resistant isolates, suggesting that they can be dominant in population if the fungicide continue to be applied.