We compared the expression patterns of three representative genes in undamaged tomato and tobacco plants in response to exposure to either tomato or tobacco fed on by Helicoverpa armigera (cotton bollworm). When tomat...We compared the expression patterns of three representative genes in undamaged tomato and tobacco plants in response to exposure to either tomato or tobacco fed on by Helicoverpa armigera (cotton bollworm). When tomato and tobacco, two species of one family, were incubated in the chambers with the tomato plants damaged by the cotton bollworm, the expression of the PR1, BGL2, and PAL genes was up-regulated in leaves of both plants. However, the levels of gene expression were significantly higher in the tomato than that in the tobacco. In addition, the activities of enzymes, peroxidase, polyphenol oxidase, and lipoxygenase were found to be higher in the tomato than those in the tobacco. Similar results were obtained when the damaged plants were replaced by the tobacco.展开更多
Three commercial neem [Azadirachta indica A. Juss (Meliaceae)]-basedinsecticides, Agroneem, Ecozin, and Neemix, and a non-commercial neem leaf powder, were evaluatedfor oviposition deterrence, antifeedant effect on la...Three commercial neem [Azadirachta indica A. Juss (Meliaceae)]-basedinsecticides, Agroneem, Ecozin, and Neemix, and a non-commercial neem leaf powder, were evaluatedfor oviposition deterrence, antifeedant effect on larvae, and toxicity to eggs and larvae of thebeet armyworm, Spodoptera exigua (Huebner) (Lepidoptera: Noctuidae), on cotton leaves in thelaboratory. Oviposition deterrence in no-choice, and two- and five-choice assays, was observed forthe neem-based insecticide treatments when compared with a non-treated control. Neem-basedinsecticides also deterred feeding by beet armyworm larvae. Direct contact with neem-basedinsecticides decreased the survival of beet army-worm eggs. Survival of beet armyworm larvae fed for7 days on leaves treated with neem-based insecticides was reduced to 27, 33, 60, and 61% for neemleaf powder, Ecozin, Agroneem, and Neemix, respectively. Possibilities for adoption of neem-basedinsecticides in commercial cotton for beet armyworm control are discussed.展开更多
文摘We compared the expression patterns of three representative genes in undamaged tomato and tobacco plants in response to exposure to either tomato or tobacco fed on by Helicoverpa armigera (cotton bollworm). When tomato and tobacco, two species of one family, were incubated in the chambers with the tomato plants damaged by the cotton bollworm, the expression of the PR1, BGL2, and PAL genes was up-regulated in leaves of both plants. However, the levels of gene expression were significantly higher in the tomato than that in the tobacco. In addition, the activities of enzymes, peroxidase, polyphenol oxidase, and lipoxygenase were found to be higher in the tomato than those in the tobacco. Similar results were obtained when the damaged plants were replaced by the tobacco.
文摘Three commercial neem [Azadirachta indica A. Juss (Meliaceae)]-basedinsecticides, Agroneem, Ecozin, and Neemix, and a non-commercial neem leaf powder, were evaluatedfor oviposition deterrence, antifeedant effect on larvae, and toxicity to eggs and larvae of thebeet armyworm, Spodoptera exigua (Huebner) (Lepidoptera: Noctuidae), on cotton leaves in thelaboratory. Oviposition deterrence in no-choice, and two- and five-choice assays, was observed forthe neem-based insecticide treatments when compared with a non-treated control. Neem-basedinsecticides also deterred feeding by beet armyworm larvae. Direct contact with neem-basedinsecticides decreased the survival of beet army-worm eggs. Survival of beet armyworm larvae fed for7 days on leaves treated with neem-based insecticides was reduced to 27, 33, 60, and 61% for neemleaf powder, Ecozin, Agroneem, and Neemix, respectively. Possibilities for adoption of neem-basedinsecticides in commercial cotton for beet armyworm control are discussed.
