›› 2006, Vol. 49 ›› Issue (1): 45-49.

• RESEARCH PAPERS • Previous Articles     Next Articles

Effect of Congo red on peritrophic membrane of Helicoverpa armigera (Hübner) and its viral-enhancing activity

ZHANG Xiao-Xia, LIANG Zhen-Pu, PENG Hui-Yin, ZHANG Zhong-Xin, TANG Xian-Chun, LI Gang, ZHAO Shu-Ling, XIAO Yu-Zhou, ZHANG Wan-Ju   

  1. Wuhan Institute of Virology, Chinese Academy of Sciences
  • Online:2006-03-03 Published:2006-02-20

Abstract:

The morphology, structure and component of normal peritrophic membrane (PM) were observed, and the disruptive effect of Congo red (CR) on the PM of larvae and its viral-enhancing activity to HaNPV in Helicoverpa armigera were studied. The results indicated that the PM of H. armigera resembled typeⅠ, which spread nearly the whole midgut and presented as a vacuole. The normal PM was colorless, transparent and stretchy. The PM dyed by CR appeared as a bisque netlike structure. When the 5th instar larvae were reared on the diets with different concentrations of CR, the larvae synthesized fragile PM fragments instead of intact PM after consuming the artificial diets with 1.5% and 2.0% CR for 2.5 h. However, the resumptive experiments testified the disruptive effect could be restored by rearing the larvae on the diet without CR. Although 1.0% CR did not affect the growth of larvae, it could enhance the sensitivity of larvae to virus infection, shorten the killing time by virus, and cause the mortality of 5th instar larvae as high as 63%.

 

Key words: Helicoverpa armigera, Congo red, HaNPV, viral-enhancing activity, midgut, peritrophic membrane