关键词: 它感素, 棉铃虫, 抗虫性

Abstract: The effects of soybean trypsin inhibitor (STI), gossypol, and tannic acid on the growth and digestive physiology of cotton bollworm, Helicoverpa armigera(Hubner) were studied. Each of three agents inhibited larval midgut proteolytic activity in vitro; STI was the most effective. When incorporated into an artificial diet,0.84% (dry weight) STI significantly reduced the high alkaline trypsin-like enzymeactivity by 18%; 0.3% tannic acid significantly decreased the low alkaline trypsin-like enzyme activity and total proteolytic activity by 22% and 18% respectively; and 0.3% gossypol had no significant effect on proteolysis. All the three agents remarkably suppressed the growth of larvae. Co-occurrences of STI and gossypol or tannic acid respectively declined the low alkaline trypsin-like enzymeactivity by 34% and 66%, the high alkaline trypsin-like enzyme activity by 33% and 55%, and the total proteolytic activity by 30% and 66%. Co-occurrence of STI and tannic acid also reduced chymotrypsin-like enzyme activity by 53%. Both gossypol and tannic acid potentiated the larval growth inhibitory activity of STI, and this implicates the protease inhibitor engineered into the cotton with high gossypol and/or tannin content may achieve greater protection against the cotton bollworm.

Key words: Soybean trypsin inhibitor, gossypol, tannic acid, Helicoverpa arrnigera (Hubner), protease