Data/hora: 05/06/2024 05:23:34

Biblioteca(s): 	Embrapa Soja.	
Data corrente: 	29/10/2008	
Data da última atualização: 	30/10/2008	
Autoria: 	CIAMPI, M. B.; MEYER, M. C.; COSTA, M. J. N.; ZALA, M.; McDONALD, B. A.; CERESINI, P. C.	
Afiliação: 	Maisa Boff Ciampi, UNESP Jaboticabal; Mauricio Conrado Meyer, CNPSo; Mauro J. N. Costa Fundação Rio Verde Lucas do Rio Verde MT; Marcelo Zala, ETH Zurich-Swiss; Bruce A. McDonald Federal Institute of Technology Plant Pathology Institute of Integrative Biology (IBZ); Paulo C. Ceresini UNESP Ilha Solteira SP.	
Título: 	Genetic structure of populations of Rhizoctonia solani AG 1-IA from soybean in Brazil.	
Ano de publicação: 	2008	
Fonte/Imprenta: 	In: INTERNATIONAL SYMPOSIUM ON RHIZOCTONIA, 4., 2008, Berlin. Abstracts... Berlin: Bayer Crop Science, 2008.	
Páginas: 	p. 49.	
Idioma: 	Inglês	
Conteúdo: 	The Basidiomycete fungus Rhizoctonia solani anastomosis group (AG)-1 IA is a major pathogen of soybean in Brazil, where the average yield losses have reached 30 to 60% in some states in Northern Brazil. No information is currently available concerning levels of genetic diversity and population structure for this pathogen in Brazil. A total of 232 isolates of R. solani AG1 IA were collected from five soybean fields in the most important soybean production areas in central-western, northern, and northeastern Brazil. These isolates were genotyped using 10 microsatellite loci. Most of the multilocus genotypes (MLGTs) were site-specific, with few MLGTs shared among populations. Significant population subdivision was evident. High levels of admixture were observed for populations from Mato Grosso and Tocantins. After removing admixed genotypes, three out of five field populations (Maranhao, Mato Grosso, and Tocantins), were in Hardy-Weinberg (HW) equilibrium, consistent with sexual recombination. HW and gametic disequilibrium were found for the remaining soybean-infecting populations. The findings of low genotypic diversity, departures from HW equilibrium, gametic disequilibrium, and high degree of population subdivision in these R. solani AG-1 IA populations from Brazil are consistent with predominantly asexual reproduction, short-distance dispersal of vegetative propagules (mycelium or sclerotia), and limited long-distance dispersal, possibly via contaminated seed. None of the soybean-infecting populations showed a reduction in population size (bottleneck effect). We detected asymmetric historical migration among the soybean-infecting populations, which could explain the observed levels of subdivision.
	
Thesagro: 	Doença de Planta; Fungo; Soja.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Soja (CNPSO)	
Exemplares: 	CNPSO - (28640-1) - UPC - PL - -- - RF 633.94 - I61217a -  - DIS