ISOLATION AND MORPHOLOGICAL CHARACTERIZATION OF USTILAGINOIDEA VIRENS, CAUSING FALSE SMUT OF RICE

Loading...
Thumbnail Image
Date
2012
Journal Title
Journal ISSN
Volume Title
Publisher
IARI, Division of Plant Pathology,
Abstract
False smut of rice, caused by the fungus, Ustilaginoidea virens, once considered a minor disease, is now an emerging disease of rice causing havoc in many rice growing areas of the world. The isolation technique of Ustilaginoidea virens has been standardized. Surface sterilization of smut balls with 1% sodium hypochlorite solution followed by 70% ethanol wash yielded better results than 0.1% mercuric chloride solution. Best growth of the fungus was achieved on potato sucrose agar medium (pH 6.0) at 27°C, where the mean colony diameter of different isolates varied from 25 to 40 mm. Incubation in dark was found highly conducive for the growth of the fungus. Ustilaginoidea virens in culture medium showed creamy white colony, which was flat or raised with slight undulations, mycelium was fluffy, compact and leathery. Chlamydospores are formed at the centre or margin of the colony, which appears orange or yellowish and later greenish. The isolated fungus was identified according to the cultural descriptions given by Sharma and Joshi (1975) and Verma and Singh (1988). The identity of the fungal pathogen of rice false smut was also confirmed through ITS sequencing which showed 98-99 per cent identity with Ustilaginoidea virens in NCBI-BLAST analysis. The perfect isolation technique coupled with information on optimization of culture conditions of Ustilaginoidea virens will immensely contribute to further studies on the fungus and the disease it caused in India.
Description
T-8695
Keywords
Ustilaginoidea virens; isolation; cultural characters; ITS sequencing.
Citation
Collections