Diversity analysis of northern Indian isolates of Ustilaginoidea virens

Abstract

False smut of rice (Ustilaginoidea virens) (Cooke) Takahashi has become an important disease causing significant yield losses in major rice producing states of India. The present study is focused on morphological, pathological and genetic characterization in different isolates of U. virens. Thirty-five isolates of U. virens collected from different areas of Punjab and adjoining states were used to study the variability. All isolates produced well-defined colonies on potato sucrose agar (PSA) medium with colony diameter ranging from 26.0 to 90.0 mm after 2 weeks of incubation. Colony color in most of the isolates was initially white which changed to yellow and finally became green. The conidia were spherical, hyaline and warty with a size ranging from 4.05–4.94 to 6.10–6.36 μm. Isolates also differed in the growth pattern from appressed, fluffy, less fluffy to raise. Among all isolates, Uv1 was found more aggressive on both rice cultivars tested (PR116 and PR114).Three isolates viz. Uv17, Uv26 and Uv28 failed to produce disease on PR 114 while the rest of the isolates differed in their virulence/aggressiveness behaviour on PR 116 and PR 114. The genetic variation among 35 isolates of U. virens by PCR amplification using ten random operon decamer primers showed polymorphism. Similarity coefficient values among U. virens isolates ranged from 0.56 to 0.97.