中国发网菌科黏菌分类及分子系统学研究

Slime moulds are an unique group in eukaryotes which are also a kind of ideal objects suitable for investigating problems in genetics, cytology, and biology. Stemonitaceae is a common and important family which were terrestrial distribution in Myxogastrea. Elenven genura, 38 species of Stemonitaceae have been reproted in China, only 18% reported in the world (17 genura, 210 speices ). Many genura and species have not been reported in China. So new resources of Stemonitaceae will be continued to explore in China. Today there are controversial issues in genera and species classification. Based on a great deal of research about taxonomy of Stemonitaceae in early stage, investigating in the field and collecting specimens nationwide will be continued, and the species deposited in Herbarium will be examined. The morphological descriptions and illustrations are going to be provided. Based on the EF-1ɑand SSUrRNA sequences, the phylogenetic tree of the genera and species of Stemonitaceae will be constructed and their phylogenetic relationships will be analyzed. Some questioned species were identifyed by life cycle of this species. The purpose of this study is identifying questioned genus and exploring new resources of Stemonitaceae, investigating the distribution of this genus in China and solving the problems by the taxonomy, phylogeny and life cycle of this family by combining the traditional taxonomic and molecular phylogeny. On these bases, the more natural taxonomic system of Stemonitaceae will be explored.

黏菌是真核生物中一类特殊的类群，是遗传学、生物学和细胞学理想的实验材料。发网菌科是黏菌中的重要类群，分布广泛。我国共计报道11属，38种，仅占世界报道的18%，相对于世界种数（17属，210种）偏少，大量属种我国从未报道过，该类群新的资源还需继续探索挖掘。目前，发网菌科黏菌属种间的分类界限仍存有较大争议。本项目拟在已开展的前期研究基础上, 继续在全国范围内广泛进行野外调查和标本采集，并结合各大标本室库存标本，进行详尽的形态学观察，描述每种黏菌的形态特征；基于EF-1α、SSUrRNA等基因片段，分析探讨发网菌科黏菌各属、种之间的系统发育关系；对于疑难种进一步根据生活史来讨论其分类地位。通过将形态学、分子系统学和生活史等研究方法相结合，综合研究我国发网菌科黏菌，可望揭示我国该科黏菌物种多样性及物种间的亲缘关系，深入认识我国该科黏菌的资源和分布特点。

本项目对我国25个国家级自然保护区、风景区和林场等地和8个国家级森林公园进行黏菌的资源与调查研究，共采集发网菌科黏菌标本2501余份，经过宏观和微观特征的观察和鉴定，共描述发网菌科黏菌12属48种。其中增补新记录属1个：蜡黏菌属 Elaeomyxa；报道发网菌科黏菌新种5个：棒轴发菌Comatricha clavicolumella，辽宁发丝菌Stemonaria liaoningensis，冬生发网菌Stemonitis brumalis，四川发网菌S. sichuanensis，平截发网菌S. planusis，报道新记录种16个，大陆新记录种1个，新记录变种2个；吉林省新记录种10个，四川新记录种14个，河南新记录种6个。填补了我国该科研究领域的分类单元。. 实验室内进行发网菌科黏菌个体发育的研究，目前完成了草生发网菌Stemonitis herbatica从孢子萌发‐原质团形成‐幼子实体‐成熟子实体的个体发育完整过程。结果表明，草生发网菌孢子萌发类型为孔出式；原质团类型为隐型，子实体形态建成前形成淡黄色的珊瑚状原质团，需足够的光照后才能形成子实体；子实体的形成过程通常在 6‐7h 内完成。填补了我国该种个体发育的基础数据。为该科内其他属种的个体发育研究奠定了基础。. 通过分子实验本研究中共得到发网菌科黏菌mtSSU序列30条；COI序列17条。基于最大简约法和贝叶斯法对发网菌科及属下分类单元进行了分子系统学研究，结果表明；发网菌科为一个单系类群；从系统发育树上可以看出锈发网菌Stemoniti axifera为复系群。序列聚在不同的分支上，从物种分布的位置可以看出采自吉林省和黑龙江省的标本聚集在一个分支，而采自中国华中，华南和西南地区的标本聚集在一个分支。项目中命名的5个新种mtSSU序列参与了构建系统发育树，分别聚集在相应的类群中，这与形态鉴定的结果吻合。同时我们确立了亚小发网菌S. smithii的分类地位。