Incorporating an herbicide resistance gene into tropical maize with inherent polygenic resistance to control Striga hermonthica (Del.) Benth

Striga hermonthica is a widespread parasitic weed species that can causeconsiderable yield loss in susceptible maize cultivars in West and CentralAfrica. To use low doses of imidazolinone herbicides for controlling thisparasite, maize cultivars should possess resistance to this group ofherbicides as they kill both maize and S. hermonthica. An imidazolinoneresistance (IR) gene was incorporated into maize inbredlines with knownfield resistance to S. hermonthica for developing IR-maize lines withgenetic resistance to the parasite. Three field trials were conducted todetermine the reaction of newly developed IR-maize inbred lines toS. hermonthica and to assess performance of selected IR inbred lines inhybrids combinations with and withoutS. hermonthicainfestation as wellas with and withoutimazapyr seed coating at twolocations.Results of theinbred trial revealed the presence of IR-maize inbred lines with distinctresistance or tolerance reactions to S. hermonthica. The hybrids formedfrom selected IR-maizeinbredlines with field resistance toS. hermonthicasustained less damage symptoms and yield loss under S. hermonthicainfestation and supported fewer emerged parasites than the susceptiblehybrid check.Also,imazapyr-coated seeds of these hybrids planted underS. hermonthica infestation sustained either no or less than 20% yield lossand supported very few emergedparasites.The IR hybridsmay be plantedwithout imazapyr seed coating in infested fields at certain intervals todelay the development of high levels of resistance to imazapyr.

Bibliographic Details

Main Authors:	Menkir, A., Chikoye, David, Lum, F.
Format:	Journal Article biblioteca
Language:	English
Published:	Wiley 2009-07
Subjects:	polygenic resistance to striga hermonthica, herbicide resistance gene, combined resistance, control option,
Online Access:	https://hdl.handle.net/10568/90355 https://doi.org/10.1111/j.1439-0523.2009.01687.x
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