目的 研究冬蟲夏草菌的生長(zhǎng)速度和動(dòng)態(tài)產(chǎn)孢量,揭示產(chǎn)孢規(guī)律和條件,探索人工繁殖的可能及評(píng)估其在對(duì)蟲害生物防治中的應(yīng)用潛力;測(cè)定它的抗異活性和抗菌譜,為對(duì)其活性產(chǎn)物的性質(zhì)研究打下基礎(chǔ)。方法 測(cè)量蟲草菌株在真菌培養(yǎng)基生長(zhǎng)時(shí)的菌落直徑變化,用孢子計(jì)數(shù)法跟蹤測(cè)定普通培養(yǎng)基和水瓊脂上單菌落的動(dòng)態(tài)產(chǎn)孢量并與相近蟲草菌進(jìn)行對(duì)比分析,用瓊脂塊法測(cè)定培養(yǎng)菌絲對(duì)致敏菌的抗異活性,測(cè)量比較抗菌圈大小和總結(jié)抗菌譜。結(jié)果 在PDA 等3種常規(guī)真菌培養(yǎng)基上,CY-8202的菌落擴(kuò)展與時(shí)間呈線性關(guān)系。動(dòng)態(tài)產(chǎn)孢量的測(cè)定表明,該菌株在適宜培養(yǎng)基上的單菌落產(chǎn)孢量可達(dá)10⁷以上,并隨著時(shí)間的延長(zhǎng)而增長(zhǎng),大約200h 后增長(zhǎng)趨于平緩。對(duì)22個(gè)致敏菌株的抗菌實(shí)驗(yàn)顯示,CY-8202培養(yǎng)菌絲對(duì)革蘭氏陽(yáng)性的枯草桿菌、四聯(lián)球菌、白色葡萄球菌以及革蘭氏陰性的普通變形桿菌、傷寒桿菌、產(chǎn)氣桿菌和沙門氏菌等7株細(xì)菌有較強(qiáng)的抑制能力,對(duì)3株霉菌和1株放線菌有輕微抑制,對(duì)酵母菌未見(jiàn)抑制影響。結(jié)論 蟲草菌絲的生長(zhǎng)和產(chǎn)孢力是有效侵染寄主的兩個(gè)重要因素,但菌絲生長(zhǎng)速度不宜作為生長(zhǎng)力強(qiáng)弱的唯一判斷指標(biāo),菌絲的穿透力更加重要;具有超量產(chǎn)孢能力是蟲草菌株強(qiáng)侵染力的一個(gè)重要標(biāo)志?？巩惢钚员砻鞫x夏草。

Object To study the growth speed and dynamic spore production of CY-8202, which is an asexual strain of entomopathogenic fungi isloated from Cordyceps sinensis (Berk.) Sacc., to explore the method of artificial culture of CY-8208 strain, to assay its antibiotic activity and spectrem and to provide the experimental basis for studies of its active components. Methods Variations in colony diameter of the cordyceps hypha cultured on the fungi media were measured. The spore-count was used to determine the dynamic colony spore outputs of the hypha on several fungi media and water agar. The agar-piece method was used to test its antibiotic activity.Results There were linear relationships between the colony extensions and the culture times on common fungi media such as PDA medium, etc.. The amounts of spore produced by the single colony of the fungi were more than 10⁷ and gradually increased, but the rates of increase tended to be gentle after 200h. Antimicrobial tests against 22 microbial strains showed strong inhibition of gram positve bacteria including Bacillus subtilis, Micrococcus tetragenus and Staphylococcus albus, and to gram negative bacteria, including Proteus vulgaris, Salmonella typhi, Aerobacter aerogenes and Salmonella sp., as well as weak inhibition of three mold strains and one actinomycetes strain, but no inhibition was observed in four yeast tested.Conclusion The growth activity and the spore-production ability of Cordyceps hypha are two important factors to infect validly its insect-host. For the growth activity, its strong penetration seems more important than its fast growth. The ability to product numerous spores of Cordyceps hypha may be an important mark of its strong infectivity to insect-host. The antimicrobial tests show that CY-8202 may secrete some metabolites which have a more broad-spectrum antibacterial activity than cordycepin isolated initially from Cordyceps militaris.