Population structure of the rice sheath blight pathogen Rhizoctonia solani AG-1 IA from India

• Published in: European journal of plant pathology Vol. 112; no. 2; pp. 113 - 121
• Main Authors: Linde, C.C, Zala, M, Paulraj, R.S.D, McDonald, B.A, Gnanamanickam, S.S
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01-06-2005; Springer Nature B.V
• Subjects: Biological and medical sciences; blight; Ceratobasidium oryzae-sativae; disease transmission; Fundamental and applied biological sciences. Psychology; fungal diseases of plants; Fungal plant pathogens; gene flow; genetic distance; Genetic diversity; genetic markers; heterozygosity; Oryza sativa; Phytopathology. Animal pests. Plant and forest protection; plant pathogenic fungi; population genetics; Population structure; restriction fragment length polymorphism; ribosomal DNA; rice; rice sheath blight; sexual reproduction; Thanatephorus cucumeris; Texas; India; Asia; United States; North America; America; rDNA analyses; Monocotyledones; Plant pathology; Microbiology; Plant pathogen; Ribosomal DNA; Population structure; Genetic distance; Ceratobasidium oryzae-sativae; Population genetics; Cereal crop; Fungi; Oryza sativa; Gene flow; Gramineae; Angiospermae; Isolate; Rhizoctonia solani; Spermatophyta; Fungi Imperfecti; excess heterozygosity; Thallophyta
• ISSN: 0929-1873; 1573-8469
• DOI: 10.1007/s10658-005-1753-3

The population structure of Rhizoctonia solani AG-1 IA causing rice sheath blight from India was evaluated for 96 isolates using seven RFLP loci. Nineteen of the isolates did not hybridise to R. solani AG-1 IA RFLP probes and rDNA analyses subsequently confirmed that they were either Ceratobasidium oryzae-sativae isolates or another Rhizoctonia sp. The population structure of the remaining 77 R. solani AG-1 IA Indian isolates was similar to that of a previously characterized Texas population. Clonal dispersal of R. solani AG-1 IA in India was moderate within fields and no clones were shared among field populations. Low levels of population subdivision and small genetic distances among populations were consistent with high levels of gene flow. Frequent sexual reproduction was indicated by the fact that most populations were in Hardy-Weinberg equilibrium (HWE). The two loci (R68 and R111) that deviated significantly from HWE showed an excess of heterozygosity. Although Texas and Indian populations were geographically very distant, they exhibited only moderate population subdivision, with an F^sub ST^ value of 0.193.[PUBLICATION ABSTRACT]