2006年在韩国松林土壤中分离出来一种稀有的丝孢菌(分离物CNU 120806)。该菌具有两种孢子,但是仅月型孢子能黏附于线虫虫体上，并感染线虫。该菌消耗线虫营养并生长出线虫虫体，形成新孢子，然后进行新的感染循环。基于形态和分子生物学特征，该菌被鉴定为Esteya vermicola,它是已经被报道过的首例松材线虫的内寄生菌。由于其高度侵染性，有希望成为防控毁灭性的松萎蔫病害的生防菌。生测表明，E.vermicola CBS 115803在4~5 d内就能感染致死几乎全部松材线虫，这是由于其产生了较多的月型孢子。研究还表明，应用该菌的配方具有防控松萎蔫病的生防商业化前景。
Abstract
The pinewood nematode (PWN) causes pine wilt disease which results in catastrophic economic loss to the forest industry. Many nematophagous organisms have been tested, including nematophagous fungi, for controlling the PWN. In 2006, a rare hyphomycetes fungus (isolate CNU 120806) was isolated from infected nematodes found in pineforest soil in south Korea. This fungus is characterized by its ability to produce two types of conidiogenous cells and conidia. However, only the lunate conidia are adhesive and can attach to the cuticle of PWNs and cause subsequent infection. With the consumption of the dead nematode’s body, E.vermicola gradually grows out from the cadavers and then produces new conidia for the next infection cycle. Based on phenotypic characteristics and molecular phylogenetic analyses, we identified the fungus as E.vermicola, the first recorded endoparasitic fungus of the PWN. Resulting from its high infectivity in vitro E.vermicola shows great promise as a biological control agent for combating the devastating pine wilting. In subsequent studies, our isolate has been described and compared with three other isolates (ATCC 74485, CBS 115803, and CBS 100821)and their detailed morphological and molecular characteristics have been determined as have their infectivity against the PWN.The results show that E.vermicola CBS 115803 kills and colonizes almost all the tested pinewood nematode isolates within 4—5 days, i.e. It is highly infectious which has been attributed to its relatively high proportion of lunate conidia. The factors that influence the infectivity of E.vermicola against the PWN and the interaction between E.vermicola and the nematode were also studied in detail. The results show that the high potential application of certain fungus formulations as a commercial biocontrol agent against the PWN.
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参考文献
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基金
IUFRO2009国际松萎蔫病研讨会学术论文摘要选登
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