Studies On Morphology And Structure Of The Spores Of Chinese Liverworts And Their Significance In Systematics And Evolution

Spore morphology and ultrastructure of bryophyte are stable and valuable not only for studies of systematics and evolution but also for conservation and utilization of plants. Based on having a good command of bryophyte systematics,the author carried out the field investingation and widely collected spore samples of liverworts of Chinese main herbaria in China. Spore morphology and ultrastructure of the liverworts were observed with Scanning Electronic Microscope (SEM) and Transmission Electronic Microscope(TEM). The systematic and evolutionary significances of the spore characters were studied and discussed.The main research result are as follows:(1)The spores of 31 families,58 genera, 115 species of liverworts were observed and studied under SEM. The morphology of 115 species of spores are reported for the first time. Morphological characters of the spores are described in detail and 59 plates are presented.(2)Spore ultrastuctures of 26 families,42 genera, 53 species of Hepaticae and Anthocerotae were studies under TEM for the first times.The results show that organization, origin of superficial ornamentation and polarity of spores can be identified and recognized by the wall ultrastructu-re.Besides,different of wall ultrastructure observed in this experiment were classified and 24 plates are presented.(3) In review of the previous researches and the results of present study,the spores of Hepaticae and Anthocerotae from China can be divided into 4 types (tetrahedron, katalept,type of Folioceros and global approximately) in morphology,The ornamentations of the spores observ-ed can also be divided into 9 types (granulate,gemmate,regulate,perforate,spinate,clavate,striate,reticulate,foveolate) in ornamentation.(4) Based on spore morphology and structure,evolutionary tendency of liverworts spore characters is discussed. The results supported the classification prepared by Kuprianova in 1974.In addition,the significance of spore morphology and ultrastructure of families Lophoziaceae and Frullaniaceae in systematics and evolution is also discussed preliminarly. The evolution tendence of the spore in Hepaticae and Anthocerotae is towards to large in size,anisopolar and complicated.