Antibiosis Mechanism of Resistance to Larger Grain Borer, Prostephanus truncatus (Horn)(Coleoptera: Bostrichidae) in Maize

Posted by Carelia Juarez on , in Journal Articles

Published in Journal of Entomology  11 (5) : 248-260, 2014

Nhamucho, E.;  Mugo, S.N.;  Kinyua, M.;  Gohole, L.;  Tadele Tefera;  Mulima, E.

Host plant resistance is a valuable component of integrated pest management in maize. Maize stored on-farm without controlled moisture content and insecticide treatment is highly susceptible to damage by Larger Grain Borer (LGB),Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae). The aim of this study was to determine the resistance of Mozambican maize genotypes against P. truncatus. Seventeen maize genotypes composed of seven experimental hybrids, one released hybrid, two improved open pollinated varieties (OPV), three landraces from Mozambique and four checks (two resistant and two susceptible) from Kenya were screened for their resistance to LGB. The F1 and F2 hybrids were evaluated at Kiboko, Kenya in a completely randomized design trial, replicated four times in a post-harvest laboratory. A selection index computed from the number of LGB, grain weight loss (%), seed damage (%) and flour weight were used to categorize the materials as either resistance or susceptible. Fifty percent of the F1 hybrids tested were resistant, 25% moderately resistant and 25% susceptible. Twenty five percent of F2 hybrids evaluated were resistant and 75% susceptible. EV8430DMRSR, an OPV and Kandjerendjere, a landrace were the most resistant genotypes with less than 10% weight loss and less than 25% seed damage. This study showed that high protein content contributed towards resistance while high starch contributed to susceptibility. It was concluded that antibiosis mechanism could contribute to LGB resistance in maize. The identified resistant genotypes could be used as cultivar or as source of resistance in maize breeding programs for resistance to LGB.

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