球孢白僵菌在棉铃虫表皮上萌发的研究

在扫描电子显微镜下,观察了球孢白僵菌三株不同毒力菌株的分生孢子在棉铃虫幼虫表皮表面的萌发,发现高、低毒力菌株的分生孢子都能在棉铃虫幼虫表皮上萌发和生长,但高毒力菌株的萌芽管伸长至分生孢子长径的1.5～2.5倍时能发生定向生长,垂直向里穿透表皮,低毒力菌株的萌芽管呈蔓延生长,极少有穿透表皮的发生,偶见极度伸长的菌丝穿透表皮。此外,还发现球孢白僵菌穿透菌丝穿透表皮的过程不是垂直向里一步完成的。

STUDIES ON BEHAVIOUR OF GERMINATION OF CONIDIA FROM BEAUVERIA BASSIANA ON THE CUTICLE OF HELIOTHIS ZEA

This paper studied on germination process of the conidia of three different virulent strains of Beauveria bassiana with scanning electron microscope (SEM) and transmission electron microscope (TEM). We discovered both high and low virulent strains in the cuticle of Heliothis zea can germinate. The germ tubes of high virulent strains were directional growth and penetrated the cuticle, when it stretched to 1.5 to 2.5 times of conidia length. The germ tubes of low virulent strains grew extensively and less penetrated cuticle. The process of hypha penetrant cuticle could not be sucessive by one step.