Data/hora: 23/09/2024 20:07:56

Biblioteca(s): 	Embrapa Soja.	
Data corrente: 	11/04/2000	
Data da última atualização: 	15/10/2004	
Autoria: 	ARIAS, C. A. A.; BROGIN, R. L.; TOLEDO, J. F. F.; YORINORI, J. T.; OLIVEIRA, M. F.	
Título: 	An improved method to evaluate the reaction of soybeans to brown.	
Ano de publicação: 	1999	
Fonte/Imprenta: 	In: WORLD SOYBEAN RESEARCH CONFERENCE, 6., 1999, Chicago. Proceedings: invited and contributed papers and posters. Chicago: University of Illinois / Soybean Research & Development Council, 1999.	
Páginas: 	p.486.	
Idioma: 	Inglês	
Conteúdo: 	Brown spot (Septoria glycines Hemmi) is ones of the most important soybean diseases in Brazil. Development of resistant varieties to brown spot has been considered a top priority in the Brazilian breeding programs. The complex genetic control and the high environmental effects on the trait decrease the efficiency of field evaluations. Three experiments were carried out to develop an alternative method for determination of soybean genotypes reaction to brown spot under greenhouse conditions. Several varieties, inbred lines and segregant generations were sown in pots filled with 4kg of a sterile fertilized soil in different dates. Pots were arranged in a completely randomized design with four to 10 replications. Two plants of the tested genotype plus one plant of the susceptible variety Davis were grown in each pot. Plants at V4 stage were sprayed with 15 ml of a suspension containing 6 x 10 spores/ml. The leaves were kept humid for three days and the evaluations were performed between 14 to 22 days after the inoculation. The leaf infection level (LIL) was determined using a scale from O to 10. The susceptible variety was used to calibrate the LIL variable and as covariate in the statistical model to adjust the genotype means for environmental effects. The method developed in this study showed to be suitable to evaluate the soybean reaction to brown spot and the genotypes could be classified as highly resistant (varieties FT-2, IAS 5, FT-10, Embrapa 63, and the line BR92-1262), resistant (Dourados, CTS-40, BR-8, RS 6, and IAC-100), moderately resistant (FT 5, Embrapa 133, MT/BR-46, MT/BR-45, Embrapa 20, and Ocepar-2), susceptible (FT-Cristalina, Ocepar-5, and Ocepar-4) and highly susceptible (Davis, Parana, and FT-9). Genetic analysis of segregating generation showed a predominance of additive genetic effects among mean and variance components. The heritability changed from 40% to 58% and indicated that it is possible to obtain significant responses to selection applying the proposed method.	
Palavras-Chave: 	Brasil; Cultivar; Soybean.	
Thesagro: 	Doença; Resistência; Septoria Glycines; Soja.	
Thesaurus Nal: 	Brazil; disease resistance; varieties.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Soja (CNPSO)	
Exemplares: 	CNPSO - (17359-1) - UPC - PL - -- - 633.34072 - W927p -  - DIS