REDBIO México 2010

Folio: 254
Tipo de presentación: Oral
Tema: Mejoramiento Genético Vegetal
Este trabajo se presentará en "Presentaciones Libres 11: Biodiversidad, Mejoramiento y Marcadores Moleculares" el Miercoles dentro del horario 14:20 a 16:20

QTL Mapping of Tropical Maize Grain Components Associated with Maize Weevil Resistance

"Silverio García-Lara 1*, and David J. Bergvinson 2 1 Dep. of Agro Biotechnology and Agro Business, Tecnológico de Monterrey, ITESM-Campus Monterrey, C.P. 64849 Monterrey, N.L., México; 2 D.J. Bergvinson, Agricultural Development. Bill & Melinda Gates Foundation. PO Box 23350. Seattle, WA. 98102, USA."

RESUMEN (ABSTRACT)
"The maize weevil (MW), Sitophilus zeamais (Motsch.), is a globally distributed pest that causes severe losses in stored maize (Zea mays L.) worldwide. A previous study identified quantitative trait loci (QTL) contributing to reduced grain damage and losses by MW in the maize mapping population CML290 x Muneng-8128C0HC1-18-2-1-1. This study was conducted to identify QTL associated with the identified biochemical bases of resistance in the maize grain. Eleven traits were analyzed on grain samples from F2 lines across two environments: p-coumaric acid (CA), cis and trans ferulic acid, (FA), four isomers of diferulic acids (DiFA), phenolic acid amides (CFP, coumaroyl-feruloyl putrescine and DFP, diferuloyl putrescine), total DiFA and total phenols acids (PhA). Significant variations were observed for most of the traits, while heritabilities ranged from 0.09 to 0.79. Ten QTL were identified for trans- and cis-FA, 8,5'-DiFA, 8-O-4'-DiFA, 8,5'-DiFAb, FAP, and CFP while seven QTL were identified for p-CA, 5,5'-DiFA, FA, total DiFAs, and total PhA. These QTL were dispersed across the maize genome and explain between 25% and 47% of the phenotypic variance (_2p) and 50% to 98% of the genotypic variance (_2g). Nine regions were common between QTL associated with MW susceptibility and cell wall bound compounds, suggesting a strong genetic association with MW resistance in tropical maize."