QTL mapping for reaction to Phaeosphaeria leaf spot in a tropical maize population

Autor(es)

Vieira Moreira, Jose Ubirajara ^[1] ; Vieira Bento, Dyeme Antonio ^[1] ; de Souza, Anete Pereira ^[2] ; de Souza, Jr., Claudio Lopes ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Genet, Agr Coll Luiz de Queiroz, BR-13400970 Piracicaba, SP - Brazil

^[2] Univ Estadual Campinas, Dept Genet & Evolut, BR-13083970 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: THEORETICAL AND APPLIED GENETICS; v. 119, n. 8, p. 1361-1369, NOV 2009.
• Citações Web of Science: 13

Resumo

Phaeosphaeria leaf spot (PLS) is an important disease in tropical and subtropical maize (Zea mays, L.) growing areas, but there is limited information on its inheritance. Thus, this research was conducted to study the inheritance of the PLS disease in tropical maize by using QTL mapping and to assess the feasibility of using marker-assisted selection aimed to develop genotypes resistance to this disease. Highly susceptible L14-04B and highly resistant L08-05F inbred lines were crossed to develop an F(2) population. Two-hundred and fifty six F(2) plants were genotyped with 143 microsatellite markers and their F(2:3) progenies were evaluated at seven environments. Ten plants per plot were evaluated 30 days after silk emergence following a rating scale, and the plot means were used for analyses. The heritability coefficient on a progeny mean basis was high (91.37%), and six QTL were mapped, with one QTL on chromosomes 1, 3, 4, and 6, and two QTL on chromosome 8. The gene action of the QTL ranged from additive to partial dominance, and the average level of dominance was partial dominance; also a dominance x dominance epistatic effect was detected between the QTL mapped on chromosome 8. The phenotypic variance explained by each QTL ranged from 2.91 to 11.86%, and the joint QTL effects explained 41.62% of the phenotypic variance. The alleles conditioning resistance to PLS disease of all mapped QTL were in the resistant parental inbred L08-05F. Thus, these alleles could be transferred to other elite maize inbreds by marker-assisted backcross selection to develop hybrids resistant to PLS disease. (AU)

• Processo FAPESP: 99/12143-1 - Uso de marcadores moleculares para mapeamento de locos que controlam caracteres quantitativos (qtls) e para selecao assistida em milho.
• Beneficiário: Cláudio Lopes de Souza Junior
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 01/05702-6 - Mapeamento de QTLs que controlam caracteres quantitativos em milho utilizando microssatélites
• Beneficiário: Milena de Luna Alves de Lima
• Modalidade de apoio: Bolsas no Brasil - Doutorado