Progeny evaluation for resistance to Phaeosphaeria leaf spot in tropical maize

Autor(es)

Lopes, Maria Teresa G. ^[1] ; Vieira, Maria Lucia C. ^[2] ; Lopes, Ricardo ^[3] ; Brunelli, Katia Regiane ^[2] ; Matiello, Rodrigo R. ^[4] ; Da Silva, Herbert P. ^[2] ; Camargo, Luis Eduardo A. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Fed Amazonas, Fac Ciencias Agr, Manaus, Amazonas - Brazil

^[2] Univ Sao Paulo, Escola Super Agr Luiz de Queiroz, BR-13418900 Piracicaba - Brazil

^[3] Embrapa Amazonia Ocidental, BR-69048660 Manaus, Amazonas - Brazil

^[4] Univ Estadual Ponta Grossa, BR-84030900 Ponta Grossa - Brazil

• Tipo de documento: Artigo Científico
• Fonte: CANADIAN JOURNAL OF PLANT PATHOLOGY-REVUE CANADIENNE DE PHYTOPATHOLOGIE; v. 33, n. 1, p. 49-53, 2011.
• Citações Web of Science: 3

Resumo

Maize breeding programmes in Brazil and elsewhere seek reliable methods to identify genotypes resistant to Phaeosphaeria leaf spot. The area under the disease progress curve (AUDPC) is an accurate method to evaluate the severity of foliar diseases. However, at least three data points are required to calculate the AUDPC, which is unfeasible when there are thousands of genotypes to be assessed. The aim of this work was to estimate the heritability of disease resistance, evaluate disease severity at different times using a nine-point scale in comparison to the AUDPC, and establish the most suitable phenological period for disease assessment. A repeated experiment was conducted in a 11 x 11 lattice experimental design with three replications. Disease assessments were carried out at flowering, 15 and 30 days post-anthesis for the parental lines DS95, DAS21, the F1 generation and 118 F2:3 progenies. Then, the AUDPC was obtained and results compared with the single-point evaluations used to calculate it. Individual and joint analyses of variance were conducted to obtain heritabiliy estimates. The assessments performed after the flowering stage gave higher estimates of heritability and correlation with AUDPC. We concluded that one assessment between the 15th and 30th day after flowering could provide enough information to distinguish maize genotypes for their resistance to Phaeosphaeria leaf spot under tropical conditions. (AU)

• Processo FAPESP: 01/02793-0 - Genes de resistência a patógenos em milho e trigo: caracterização por meio de marcadores moleculares
• Beneficiário: Luis Eduardo Aranha Camargo
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 99/09170-7 - Mapeamento de genes de resistência a Phaeosphaeria maydis em milho
• Beneficiário: Maria Teresa Gomes Lopes
• Modalidade de apoio: Bolsas no Brasil - Doutorado