Rice false smut instigated by the fungus Ustilaginoidea virens, has emerged as one of the most devastating grain diseases in the major rice-growing regions worldwide. A total of fifty-six distinct isolates of U. virens collected from different states of India were used for morphological and molecular characterization. Isolates showed variation in the size of the spore, radial growth, colony color and morphology. The chlamydospores were round to elliptical and warty on the surface ranging from 4.12 to 6.34 μm in diameter. The maximum colony diameter was found in Telangana isolate Uv305 (66.00 mm) and the minimum was in Uttar Pradesh isolate Uv214 (17.50 mm). All the 56 isolates taken for the study were confirmed through Internal Transcribed Spacer (ITS) based sequence analysis. Phylogenetic tree based on the ITS region grouped the isolates into two major clusters. Further, genetic diversity was analyzed by using 12 Simple Sequence Repeat (SSR) primers out of which 7 were found to be polymorphic. A total of 56 alleles and 49 loci with an average of 0.875 alleles per locus were identified. The highest genetic diversity was calculated using the marker UvSSR276 (PIC value 0.919) followed by UvSSR226 and UvSSR97 having PIC value of 0.891 and 0.887 respectively. The dendrogram generated based on polymorphic data grouped the isolates into two main clusters independent of their geographical origin. Higher variance was detected within populations/individuals (88%) compared to among the populations (12%). High morphological while moderate molecular and intra-population genetic diversity was observed in U. virens isolates causing rice false smut disease in India. This in-depth understanding of population structure and diversity of U. virens will be helpful in designing the breeding programs to effectively manage rice false smut disease on a comprehensive scale.
Biological and molecular characterization of Ustilaginoidea virens, an emerging pathogen of rice in India
Matic, Slavica;
2025
Abstract
Rice false smut instigated by the fungus Ustilaginoidea virens, has emerged as one of the most devastating grain diseases in the major rice-growing regions worldwide. A total of fifty-six distinct isolates of U. virens collected from different states of India were used for morphological and molecular characterization. Isolates showed variation in the size of the spore, radial growth, colony color and morphology. The chlamydospores were round to elliptical and warty on the surface ranging from 4.12 to 6.34 μm in diameter. The maximum colony diameter was found in Telangana isolate Uv305 (66.00 mm) and the minimum was in Uttar Pradesh isolate Uv214 (17.50 mm). All the 56 isolates taken for the study were confirmed through Internal Transcribed Spacer (ITS) based sequence analysis. Phylogenetic tree based on the ITS region grouped the isolates into two major clusters. Further, genetic diversity was analyzed by using 12 Simple Sequence Repeat (SSR) primers out of which 7 were found to be polymorphic. A total of 56 alleles and 49 loci with an average of 0.875 alleles per locus were identified. The highest genetic diversity was calculated using the marker UvSSR276 (PIC value 0.919) followed by UvSSR226 and UvSSR97 having PIC value of 0.891 and 0.887 respectively. The dendrogram generated based on polymorphic data grouped the isolates into two main clusters independent of their geographical origin. Higher variance was detected within populations/individuals (88%) compared to among the populations (12%). High morphological while moderate molecular and intra-population genetic diversity was observed in U. virens isolates causing rice false smut disease in India. This in-depth understanding of population structure and diversity of U. virens will be helpful in designing the breeding programs to effectively manage rice false smut disease on a comprehensive scale.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
