Genetic structure of populations of Rhizoctonia solani AG-3 on potato in eastern North Carolina

A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was developed to identify and differentiate genotypes of Rhizoctonia solani anastomosis group 3 subgroup PT (AG-3 PT), a fungal pathogen of potato. Polymorphic co-dominant single-locus PCR-RFLP markers were identified after sequencing of clones from a genomic library and digestion with restriction enzymes. Multilocus genotypes were determined by a combination of PCR product and digestion with a specific restriction enzyme for each of seven loci. A sample of 104 isolates from one commercial field in each of five counties in eastern North Carolina was analyzed, and evidence for high levels of gene flow between populations was revealed. When data were clone-corrected and samples pooled into one single North Carolina population, random associations of alleles were found for all loci or pairs of loci, indicating random mating. However, when all genotypes were analyzed, the observed genotypic diversity deviated from panmixia and alleles within and between loci were not randomly associated. These findings support a model of population structure for R. solani AG-3 PT on potato that includes both recombination and clonality.

Rhizoctonia solani AG groups in northeast India

Rhizoctonia solani isolates collected from different crops in northeast India belonged to anastomosis group AG 2-2 IIIB (Canavalia ensiformis, Sechium edule, Glycine max and Dolichos lablab). AG 11A was detected on Zea mays, Rhizoctonia solani on Sechium edule and AG 4HG-II on a weed, Galinsoga parviflora, which are new records from India. © Australasian Plant thology ociety 2010.

Population genetic evidence that basidiospores play an important role in the disease cycle of rice-infecting populations of Rhizoctonia solani AG-1 IA in Iran

The fungus Rhizoctonia solani AG-1 IA causes sheath blight, one of the most important rice diseases worldwide. The first objective of this study was to analyse the genetic structure of R. solani AG-1 IA populations from three locations in the Iranian Caspian Sea rice agroecosystem. Three population samples of R. solani AG-1 IA isolates were obtained in 2006 from infected rice fields separated by 126-263km. Each field was sampled twice during the season: at the early booting stage and 45days later at the early mature grain stage. The genetic structure of these three populations was analysed using nine microsatellite loci. While the population genetic structure from Tonekabon and Amol indicated high gene flow, they were both differentiated from Rasht. The high gene flow between Tonekabon and Amol was probably due mainly to human-mediated movement of infested seeds. The second objective was to determine the importance of recombination. All three populations exhibited a mixed reproductive mode, including both sexual and asexual reproduction. No inbreeding was detected, suggesting that the pathogen is random mating. The third objective was to determine if genetic structure within a field changes over the course of a growing season. A decrease in the proportion of admixed genotypes from the early to the late season was detected. There was also a significant (P=0·002) increase in the proportion of loci under Hardy-Weinberg equilibrium. These two lines of evidence support the hypothesis that basidiospores can be a source of secondary inoculum. © 2012 BSPP.

Variação genética e adaptabilidade evolutiva de Rhizoctonia solani AG-1 da soja sob condições de estresse

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Rhizoctonia solani AG-1: estrutura genética, etiologia e evolutibilidade nos agroecossitemas Brachiaria spp. e arroz na Colômbia

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Diversidade genética e estrutura de populações de Rhizoctonia solani AG-1 IA no Brasil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relato de Rhizoctonia solani AG-4 HG I em crisântemo (Papiro Branco e Amarelo) e R. solani AG-4 HG III em gipsófila no estado de São Paulo, Brasil, e sua patogenicidade cruzada

Currently, anastomosis groups (AG) of Rhizoctonia sp. on chrysanthemum and occurrence of this fungus on gypsophila have not been reported in Brazil. However, in the present study, normal and cross pathogenicity and sequencing of ITS-5.8S rDNA regions were used to confirm the AG of isolate of Rhizoctonia sp. obtained from chrysanthemum (White Papyrus) and from gypsophila plants cultivated in Holambra / São Paulo, Brazil. After these tests, it was confirmed the report of Rhizoctonia solani AG-4 HG I on chrysanthemum (White and Yellow Papyrus) and R. solani AG-4 HG III on gypsophila in the São Paulo state, Brazil, and also their cross pathogenicity.

A origem de populações emergentes do patógeno da queima-da-folha (Rhizoctonia solani AG-1 IA) da Urochloa spp. na Amazônia e seu potencial de adaptação a outros agroecossistemas brasileiros

Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV

Direct support and general support maintenance manual : survey instrument, azimuth, gyro, lightweight (Lear Siegler, Inc. models AG-8 and AG-8A) NSN 6675-00-062-8579.

Includes index.

Organizational maintenance repair parts and special tools list : survey instrument, azimuth gyro, lightweight, (Lear Siegler, Inc. models AG-8 and AG-8A), NSN 6675-00-062-8579.

Includes index.

Operator's manual : survey instrument, azimuth, gyro, lightweight, model AG-8, type 1 (6675-00-062-8579).

"30 June 1986."

Direct support and general support maintenance repair parts and special tools list (including depot maintenance repair parts and special tools) : survey instrument, azimuth, gyro, lightweight (Lear Siegler, Inc. models AG-8 and AG-8A), NSN 6675-00-062-8579.

Includes index.

Organizational maintenance manual : survey instrument, azimuth, gyro, lightweight, model AG-8, type 1 (6675-00-062-8579).

"22 April 1987."