Antixenosis and antibiosis resistance toCeutorhynchus obstrictusin novel germplasm derived fromSinapis albaxBrassica napus

Abstract

AbstractIntrogression of cabbage seedpod weevil,Ceutorhynchus obstrictus(Marsham) (Coleoptera: Curculionidae), resistance fromSinapis albaL. to susceptibleBrassica napusL. (Brassicaceae) has produced genetic lines resistant to the weevil in replicated field trials. In the current study, weevil feeding and oviposition onS. albaand on resistant novel lines developed by crossingS. alba×B. napuswere less frequent than on susceptible germplasm.Development times were greater and biomass was less when larvae were reared on resistant lines orS. alba. Oocyte development was faster in post-diapause springtime adult female weevils caged on susceptible plants than in those on a resistant line,S. alba, or an early-season food host,Thlaspi arvenseL (Brassicaceae). Our results suggest that antixenosis resistance and antibiosis resistance are expressed by resistant lines. These results and previous chemical analyses of these lines also suggest that resistance is potentially influenced by attractive and (or) feeding-stimulant effects of 2-phenylethyl glucosinolate and antifeedant or toxic effects of 1-methoxy-3-indolylmethyl glucosinolate.