Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/6/2002
Publication Date: 5/8/2002
Citation: Lapointe, S.L. and Kim D. Bowman. 2002. Is There Meaningful Plant Resistance to Diaprepes abbreviatus (Coleoptera: Curculionidae) in Citrus Rootstock Germplasm? Journal of Economic Entomology. 95(5):1059-1065. Interpretive Summary: To date, there has been no evidence to indicate that meaningful plant resistance to the Diaprepes root weevil exists within sexually compatible citrus rootstocks. A lack of precision in the tests available to researchers has limited their ability to detect differences between very similar rootstocks. However, when two populations of progeny from crosses of trifoliate rootstocks were tested, there was clear evidence of genetic control of resistance. This is the first time resistance has been demonstrated within sexually compatible rootstocks and points the way towards further breeding efforts for citrus improvement through breeding.
Technical Abstract: Host plant resistance to the Diaprepes root weevil, Diaprepes abbreviatus (L.) was assessed for seedlings of 56 Poncirus trifoliata (L.) selections and two families of progeny from crosses between citrus and P. trifoliata. Weight gain was consistently lower when larvae were reared in pots containing the progeny of 'Sunki' x 'Flying Dragon' compared with larvae reared on progeny of 'Pearl' x 'Flying Dragon'. This is the first evidence of genetic control of resistance to the Diaprepes root weevil within sexually compatible citrus rootstocks. There was a significant positive correlation between percentage root loss and larval weight gain within the resistant progeny, indicating a possible antibiotic or antixenotic effect. Two varieties of P. trifoliata were identified as more resistant than 'Flying Dragon' based on larval weight gain.