关键词: 食线虫真菌；专性内寄生；圆锥掘氏梅里霉；侵染周期；分生孢子

Abstract:

Nematophagous fungus plays a key role in the area of nematode biological control, and has received increasing attention in recent years. Drechmeria coniospora is a typical obligate endoparasitic fungus, which specifically infects and parasites in its host nematodes. This study observed the entire process of D. coniospora infecting Caenorhabditis elegans by using high resolution scanning electron microscope (SEM). Thus, a direct and objective evidence was obtained for further studies on infection by D. coniospora and relevent genes involved in infection. The SEM images showed that D. coniospora recognized nematode by conidia, then adsorbed nematodes mouth cavity or vulva, and got into nematode. Conidia initially germinated and formed trophic hyphae inside the nematode. When trophic hyphae growth to certain extent, mycelia penetrated nematode cuticle, which led to the death of the host. Aerial mycelia produced new conidia. After these conidia were matured, another infection cycle began. The specific infection pattern and efficient infection ability of D. coniospora made it as a potential and superior strain for biological control against nematode. D. coniospora has a broad application prospect.

Key words: nematophagous fungus, obligate endoparasitic, Drechmeria coniospora, infection cycle, conidia