Morphological and growth variations of 𝘊𝘰𝘭𝘭𝘦𝘵𝘰𝘵𝘳𝘪𝘤𝘩𝘶𝘮 isolates associated with anthracnose disease of banana

Abstract

Anthracnose is a highly destructive post-harvest disease of banana caused by the fungal pathogen 𝘊𝘰𝘭𝘭𝘦𝘵𝘰𝘵𝘳𝘪𝘤𝘩𝘶𝘮 𝘮𝘶𝘴𝘢𝘦. The present study was conducted to determine the growth and morphological variations among 𝘊𝘰𝘭𝘭𝘦𝘵𝘰𝘵𝘳𝘪𝘤𝘩𝘶𝘮 spp. associated with anthracnose disease of banana. Sixteen 𝘊𝘰𝘭𝘭𝘦𝘵𝘰𝘵𝘳𝘪𝘤𝘩𝘶𝘮 isolates, including 𝘊. 𝘮𝘶𝘴𝘢𝘦 which were isolated from a range of banana cultivars showing typical anthracnose symptoms and collected from different locations were used for the study. Colony characteristics, growth rate, spore dimensions and sensitivity to fungicides (𝘪𝘯 𝘷𝘪𝘵𝘳𝘰) were used to determine morphological variations of the fungal isolates. Out of the sixteen 𝘊𝘰𝘭𝘭𝘦𝘵𝘰𝘵𝘳𝘪𝘤𝘩𝘶𝘮 isolates, four isolates were identified as 𝘊. 𝘨𝘭𝘦𝘰𝘴𝘱𝘰𝘳𝘪𝘰𝘪𝘥𝘦𝘴 and another four were identified as 𝘊. 𝘢𝘤𝘶𝘵𝘢𝘵𝘶𝘮 based on colony and spore morphology. Colony growth rate was highly variable among the tested isolates of 𝘊𝘰𝘭𝘭𝘦𝘵𝘰𝘵𝘳𝘪𝘤𝘩𝘶𝘮 and the highest growth rate was shown by 𝘊. 𝘮𝘶𝘴𝘢𝘦. Recommended dosage of the fungicide Homai (Thiophanate-methyl 50% + Thiram 30% WP) completely inhibited the mycelial growth of all isolates tested 𝘪𝘯 𝘷𝘪𝘵𝘳𝘰. However, the recommended dosage of Daconil (Chlorothalonic 500g/L) did not completely control any of the isolates of 𝘊𝘰𝘭𝘭𝘦𝘵𝘰𝘵𝘳𝘪𝘤𝘩𝘶𝘮 tested under 𝘪𝘯 𝘷𝘪𝘵𝘳𝘰 conditions. The findings revealed that morphological and growth variations exist among the 𝘊𝘰𝘭𝘭𝘦𝘵𝘰𝘵𝘳𝘪𝘤𝘩𝘶𝘮 isolates recovered from anthracnose developed-banana fruits.