Chen Yue Qin, Wang N, Qu L -H., Li T -H., Zhang W -M.
Biotechnology Research Center, Zhongshan University, 510275, Guangzhou, People's Republic of China
Biochem Syst Ecol. 2001 Jun;29(6):597-607. doi: 10.1016/s0305-1978(00)00100-9.
The anamorph determination of Cordyceps sinensis remains problematic due to the lack of clear links between the sexual and conidial forms of the fungus. In this study, we applied molecular approaches to analyze the genetic variation of Cordyceps sinensis and its allies to identify the anamorph-teleomorph connection. The sequences of the internal transcribed spacers (ITS1 and ITS2) and 5.8S ribosomal RNA gene of Cordyceps sinensis (teleomorph) collected from Qingzang plateau (altitude over 4000m), Tibet and several related asexual conidial forms were determined. The sequence comparison showed that Cordyceps sinensis was most closely related to Hirsutella sinensis, and was clearly divergent from Paecilomyces sinensis, Stachybotrys sp. or Tolypocladium sp.; distance values, estimated according to Kimura two-parameter models between Cordyceps sinensis and Hirsutella sinensis, were extremely low (<0.02), whereas distance values between Cordyceps sinensis and Paecilomyces sinensis, Stachybotrys sp. and Tolypocladium sp. were 0.34, 0.21 and 0.25, respectively. Taken together, Hirsutella sinensis and Cordyceps sinensis are the different stages of the life cycle stages of the same organism. Hirsutella sinensis is therefore the anamorph of Cordyceps sinensis, rather than Paecilomyces sinensis or other species. The possible reasons as to why different taxa can be obtained when culturing Cordyceps sinensis are also discussed.
由于中华虫草有性型和分生孢子型之间缺乏明确联系，其无性型的确定仍然存在问题。在本研究中，我们应用分子方法分析中华虫草及其近缘种的遗传变异，以确定无性型与有性型的联系。测定了从西藏青藏高原（海拔4000米以上）采集的中华虫草（有性型）及其几种相关无性分生孢子型的内部转录间隔区（ITS1和ITS2）和5.8S核糖体RNA基因序列。序列比较表明，中华虫草与中华被毛孢关系最为密切，与中华拟青霉、葡萄穗霉属或枝顶孢属明显不同；根据Kimura双参数模型估算，中华虫草与中华被毛孢之间的距离值极低（<0.02），而中华虫草与中华拟青霉、葡萄穗霉属和枝顶孢属之间的距离值分别为0.34、0.21和0.25。综上所述，中华被毛孢和中华虫草是同一生物体生命周期的不同阶段。因此，中华被毛孢是中华虫草的无性型，而非中华拟青霉或其他物种。本文还讨论了培养中华虫草时可能获得不同分类单元的原因。
