Morphometric and internally transcribed spacer gene sequence-based characterization of Alternaria burnsii

摘要

Alternaria burnsii, the pathogen responsible for cumin blight, was collected from diseased plant samples from North Gujarat. AB-01 showed maximum growth at 28 +/- 1 degrees C. Conidia ranged from 44.92 to 63.28 mu m in length and 10.84 to 24.36 mu m in width whereas beak length of conidia ranged from 20.34 to 47.85 mu m. The isolate AB-01 showed the highest sporulation frequency (1.24 x 10(5)/ml), but the highest percentage of disease intensity was observed in AB-08 (31.4). Internally transcribed spacer gene sequence based phylogenetic grouping using MEGA5.6 and the factorial analysis using DARwin5 reflect the presence of two distinct groups. The fast growing isolates that show high pathogenicity are present in group-I of the dendrogram whereas the members of group-II show grey black colony colour, light brown colony margin, plain irregular growth pattern, and comparatively larger beak length of conidia.