Evaluation Of Aphidicidal Activity Of6Alkaloids And Their Combinations From Sophora Alopecuroides L.

Alkaloids from Sophora alopecuroides L. are the main component of the Sophora alopecuroides. Now it is clear that the alkaloids from Sophora alopecuroides L. has the aphidicidal activity on Lipaphis erysimi (Kaltenbach) and Aphis craccinora Koch. But it has not been sured that the aphidicidal spectrum and the interaction among individual alkaloids. In order to develop biorational aohidicide with alkaloids from Sophora alopecuroides L. reasonably, this research determined the toxicity of the total alkaloid and6individual alkaloids (matrine, oxymatrine, sophocarpine, sophoridine, aloperine and cytisine) and their combinations from Sophora alopecuroides L. by topical application against Myzus persicae Sulzer, Aphis craccinora Koch, Macrosiphum avenae Fabricius, Aphis citricola van der Goot, Macrosiphum rasivorum Zhang, Brevicoryne brassicae Linnaeus and Aphis sp..1. The total alkaloid and6individual alkaloids from Sophora alopecuroides L. have showed high aphidicidal activity against Myzus persicae Sulzer, Aphis craccinora Koch, Macrosiphum avenae Fabricius, Aphis citricola van der Goot, Macrosiphum rasivorum Zhang, Brevicoryne brassicae Linnaeus and Aphis sp.. But there are significant differences among individual alkaloids against the aphids tested. The toxicity of the total alkaloids and6alkaloids were ordered from high to low as follows.On Myzus persicae Sulzer, ranking order is aloperine, cytosine, sophoridine, sophocarpine, matrine and oxymatrine.On Aphis craccinora Koch, ranking order is cytosine, matrine, aloperine, sophocarpine, oxymatrine and sophoridine.On Macrosiphum avenae Fabricius, ranking order is cytosine, sophoridine, matrine, aloperine, sophocarpine and oxymatrine.On Aphis citricola van der Goot, ranking order is cytosine, sophoridine, aloperine, matrine, sophocarpine and oxymatrine.On Macrosiphum rasivorum Zhang, ranking order is cytosine, sophoridine, matrine, aloperine, sophocarpine and oxymatrine.On Brevicoryne brassicae Linnaeus, ranking order is matrine, cytosine, sophocarpine, sophoridine, oxymatrine and aloperine. On Aphis sp., ranking order is cytosine, aloperine, sophoridine, sophocarpine, matrine and oxymatrine.2. combined action among6alkaloidIn the binary mixture, there are10combinations showed synergistic effect. Cytisine mixed with other single alkaliod showed synergy. Toxicity ratio of cytisine and sophocarpine is1.35.In the triad mixture, there are17combinations exhibit synergy effect. Toxicity ratio of the combination (cytisine+oxymatrine+sophocarpine) is1.58.All of15combinations showed synergistic effect in four-compositions mixture. The combination (cytisine+aloperine+oxymatrine+sophocarpine) exhibits synergy effect most obviously and the toxicity ratio was1.62.There are4combinations showed synergistic effect. Toxicity ratio of combination (cytisine+aloperine+matrine+oxymatrine+sophocarpine) was1.27. it is lower than the combination (cytisine+aloperine+oxymatrine+sophocarpine).Toxicity ratio of6-compositions mixture was1.26, which is lower than5-compositions mixture combination (cytisine+aloperine+matrine+oxymatrine+sophocarpine).In short, alkaloids from Sophora alopecuroides L. showed high aphidicidal activity and have broad spectrum. As the main aphidicidal alkaloid of Sophora alopecuroides L., cytisine and sophocarpine have synergistic with the other alkaloids. So cytisine and sophocarpine can be main ingredient to develop efficient aphidicide of alkaloid from Sophora alopecuroides L.