Title:	GC-91, a broad-based rice synthetic population for blast (Pyricularia grisea Sacc.) resistance.
Authors:	GUIMARÃES, E. P. CORREA-VICTORIA, F. TULANDE, E.
Affiliation:	ELCIO PERPETUO GUIMARAES, CNPAF; FERNANDO CORREA-VICTORIA, CIAT; EDGAR TULANDE, CIAT.
Date Issued:	1995
Citation:	Brazilian Journal of Genetics, v. 18, n. 4, p. 553-561, 1995.
Description:	Population improvement rnethods used in cross-pollinated crops have not been extensively applied to rice (Oryza sativa L.). This article describes the formation of and selection within a genetically broad-based gene pool for resistance to rice blast (Pyricularia qrisea Sacc.), and progress during one generation of selection. Thirtv rice lines of diverse origin were chosen as parents based upon stability of the reaction of the lines to a range of leaf (BI) and panicle (NBI) blast races during eight growing seasons at a location favorable for disease development ("hot spot" site). Each parent was crossed to five other parents and each F1 to three other F1's to ensure recombination. The resulting seeds were bulked to form the GC-91 gene pool (COPO). Genetic diversity, as measured by geographical origin of the germplasm, was higher in the GC-91 than in the "genetic core" of rice varieties grown in Latin America and the Caribbean. Three groups were selected from GC-91, based upon three different objectives of selection for blast: a) rapid fixation of major genes for high levels of resistance (population C1P1, b) gradual accumulation of polygenes for partial resistance (population C1P2), and c) a combination of objectives a and b (population C1P3). Lines se!ected had greater resistance to Bl and NBl in populations C1P1 and C1P3 compared to COPO, while there was no evidence of successful selection for C1P2.
Thesagro:	Arroz Oryza Sativa Brusone Pyricularia Oryzae Resistência Genética
NAL Thesaurus:	Rice Blast disease
Keywords:	CG-91 Genetic diversity
Type of Material:	Artigo de periódico
Access:	openAccess
Appears in Collections:	Artigo em periódico indexado (CNPAF)