Abstract
Nam Dork Mai See Tong mango is a deluxe commercial fruit in Thailand, however anthracnose disease becoming a major problem affecting market-driven. Fungicide treatment is the main component in the mango anthracnose management, notwithstanding the appearance of fungal-resistance has been become a factor of fungicide limition and can affect to increasingly higher costs. Thirty-two isolates of the Colletotrichum species complex were obtained from anthracnose-diseased mango cv. Nam Dork Mai See Tong in 3 provinces of Thailand. Fungal identification based on morphological and molecular markers was investigated. All isolates were divided into 3 species: C. asianum , C. gloeosporioides and C. siamense . Pathogenicity tests revealed that all 3 species caused symptoms on artificially unwounded mango fruits and leaves. Only C. gloeosporioides have previously been reported on mango, while C. asianum and C. siamense were first reports associated with mango in Thailand. The responsiveness of Colletotrichum isolates to carbendazim was evaluated using an MIC assay. Nine isolates of C. asianum were highly resistant, while 5 and 8 isolates of C. gloeosporioides were resistant (R) and highly resistant (HR), respectively. Moreover, all isolates of C. siamense were HR. Mutations were detected by PCR of a partial sequence of the β-tubulin gene. The sequence of β-tubulin gene in HR strains showed a single nucleotide transversion of adenine to cytosine, resulting in a substitution at codon 198. However, R strains were found to have only an amino acid change at codon 200. Additionally, PCR-RFLP was applied as a rapid technique to detect carbendazim resistance. The results demonstrated that only the Bsh 1236I restriction enzyme generated two bands (200 and 300 bp) in the highly resistant strain, but these bands were absent in the sensitive (S) and R strains. Hence, PCR-RFLP technique showed the potential to specifically detect benzimidazole fungicide resistance in 3 species of Colletotrichum. Moreover, this technique is accessible and feasible for laboratory assessment
β-Tubulin Gene Based PCR-RFLP Method for Specific Detection ofBabesia bigeminaandTheileria annulataIsolates
