AGRIS 97-091411

Peer-review: Yes - Open Access: Yes|http://science.thomsonreuters.com/cgi-bin/jrnlst/jlresults.cgi?PC=MASTER&ISSN=0011-183X

Sugarcane borer (SCB), Diatraea saccharalis Fabricius, is a serious pest in tropical maize production areas in the Americas. Little is known about the genetic resistance of maize genotypes to this pest. In this study, we mapped and characterized quantitative trait loci (QTL) affecting resistance to the leaf feeding generation of SCB (1SCB), grain yield under both protection (GYP) and infestation (GYI) with SCB larvae, and plant height (PHT). A total of 171 F-2 genotypes derived from cross CML131 (susceptible) x CML67 (resistant) and 93 RFLP marker loci were used in QTL analyses. F-3 lines were evaluated for the above traits and grain yield reduction (GYR) in field experiments with two replications at two or three tropical environments. Resistance was assessed by rating leaf feeding damage after artificial infestation with SCB larvae. The method of composite interval mapping with selected markers as cofactors was used for detection and characterization of QTL. Resistance to 1SCB was significantly affected by 10 putative QTL on Chromosomes 1, 2, 5, 7, 8, 9, and 10. These showed predominantly additive gene action and explained 65.0% of the phenotypic variance and 93.5% of the genetic variance in a simultaneous Bt. Six QTL for GYP, Eve QTL for GYI with primarily dominant genetic effects, and Pour QTL for PHT with primarily additive genetic effects were identified, explaining in total about one third of the phenotypic variance for the respective trait. No more than one putative QTL was found to be common between different characters. QTL x environment interaction was found to be significant for 1SCB ratings only. Based on these data, prospects for improving 1SCB resistance by marker-assisted breeding are promising

English

Crop Science Society of America (CSSA)

DE-UHo 1997 BOHN D r

Lucia Segura

CIMMYT Staff Publications Collection