壳聚糖杀虫与壳低聚糖抑菌活性研究

Insecticidal activities with chitosan and oligo-chitosan

对以壳聚糖及壳低聚糖为有效成分的天然农药 ,分别进行室内杀虫和抑菌活性实验。结果表明 ,壳聚糖对鳞翅目和同翅目害虫均存在一定的杀虫活性。在相同浓度下 ,对小菜蛾的杀虫活性高于棉铃虫 ;对不同蚜虫的杀虫活性 ,一般在 6 0 %～ 80 %之间 ,最高可达 99%。并用室内离体平皿法检验测定了以壳低聚糖为有效成分的药剂对 17种植物病原菌生长的抑制作用。结果表明 ,壳低聚糖对其中 16种病原菌都有抑制作用 ,且随着浓度提高作用增强。药剂对芦笋茎枯病原菌的最佳抑制率可达 95 1% ,对黄瓜枯萎病、水稻纹枯病及棉花枯萎病等重要植物病害的病原菌也可达 80 %以上的抑制效果。

Efficacy of natural compounds, chitosan and oligo-chitosan, to several kinds of crop pests and fungi was investigated in laboratory. The results indicate that chitosan has insecticidal activity to the lepidopterous pest and homopterous to a certain extent. At the same concentration of chitosan, the insecticidal activity to Plutella xylostella is higher than the activity to Spodoptera exigua Hübner and Spodoptera exigua Hübner. To six sorts of aphides, the insecticidal activity of chitosan is generally between 60%～80%,and the maximum is 99%. Oligo-chitosan is effective to 16 kinds of fungi, and with the increase of its concentration the effect improves. The best inhibited probability to Phomopsis asparagi (sacc.a) Bubak is 95.1%,and the inhibited probability to Fusarium oxysporum (Schl.) f. sp. Cucumernum Owen, Rhizoctonia Solani Kuhn and Fusarium oxysporum Schl. F. Sp. uasinfectum (Atk.) Snyd. & Hans. can also be beyond 80%.