Interactions among insect-resistant soybean genotypes extracts with populations of Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae) susceptible and resistant to its nucleopolyhedrovirus.
Two major orthodihydroxy phenolics ofLycopersicon esculentum, rutin and chlorogenic acid, have previously been identified as potential sources of host-plant resistance against the tomato fruitwormHeliothis zea. We report here the possible incompatibility of these chemically based resistance factors with viral control ofH, zea. We have found that both rutin and chlorogenic acid significantly inhibited the infectivity of nuclear polyhedrosis viruses. Chlorogenic acid, when added to tissue culture medium containing TN-368 ovarian cells, inhibited the infectivity of a multiply embedded virus (AcMNPV) by over 86%. Rutin or chlorogenic acid, when fed toH. zea, inhibited the infectivity of a singly embedded nuclear polyhedrosis virus (HzSNPV), with the greatest degree of inhibition occurring at low doses of viral inoculum. Additionally, the ingestion of these phytochemicals significantly prolonged the survival time of virally infectedH. zea larvae. These results suggest that the effectiveness of nuclear polyhedrosis viruses in controllingH. zea populations may be adversely affected by varieties ofL. esculentum with significant levels (eg. 3.5 μmol/g wet weight) of rutin or chlorogenic acid.