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Biosystematics of Sino-Japanese pteridophytes

中日蕨类植物生物系统学

基本信息

批准号：
02454017
负责人：
IWATSUKI Kunio
金额：
$ 4.03万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

项目摘要

1. Matteuccia intermedia has been considered to be of hybrid origin and is a key species for understanding the phylogeny of onocleoid ferns. Comparative morphology of pneumatophores and grooves on leaf axes, cytology, and enzyme electrophoresis indicate that the species is a distinct species closely related to Onoclea orientalis.2. Cytotaxonomic studies were made for 90 fern species from Yunnan, southwestern China. They recorded for the first time the basic chromosome numbers of Gymnogrammitis (x=36) and Sorolepidivm (x=c. 35), and confirmed the basic numbers reported so far for most Chinese genera. A cytogeographic study sugested that Chinese fern flora is more diverse and ancestral than the Japanese. Our results also showed that there is a strong correlation between triploids and agamospory, as is known for fern in the other regions.3. Molecular systeamtic studies were made to examine the phylogenetic relationships of pteridophytes and seed plants.(1) The gene map of Adiantum capillus-veneris chloroplast DNA much differs from typical angiosperm chloroplast genome in gene order and organization. At least two inversions and elongation of the inverted repeat is postulated to account for the difference.(2) Maximum likelihood analysis of deduced amino acid sequences of rbcL gene indicates that Botrypus, which has been considered as a progymnosperm, clusters monophyletically with the other ferns, in which the closest relative is Osmunda, and that ferns and seed plants cluster monophyletically, and ferns and bryophytes do not belong to a monophyletic group.(3) Results of a rbcL gne study indicate that extant gymnosperms are monophyletic and not paraphyletic, and in Gnetopsida, Gnetum and Welwitschia are more closely related to one another thar either to Ephedra.

1. Matteuccia intermedia被认为是杂交起源的，是了解onoccleoid蕨类植物系统发育的关键物种。气孔和叶轴沟槽的比较形态、细胞学和酶电泳表明该物种是与Onoclea orientalis密切相关的独特物种。 2．对来自中国西南部云南的 90 种蕨类植物进行了细胞分类学研究。他们首次记录了Gymnogrammitis (x=36)和Sorolepidivm (x=c.35)的基本染色体数目，并证实了迄今为止报道的大多数中国属的基本染色体数目。一项细胞地理学研究表明，中国蕨类植物区系比日本蕨类植物区系更加多样化和古老。我们的结果还表明，三倍体和无囊孢子之间存在很强的相关性，正如其他地区的蕨类植物所知道的那样。3．对蕨类植物和种子植物的系统发育关系进行了分子系统研究。(1)铁线蕨叶绿体DNA基因图谱在基因顺序和组织上与典型被子植物叶绿体基因组有很大差异。推测至少有两次倒位和倒转重复序列的延伸可以解释这种差异。(2)对rbcL基因推导的氨基酸序列进行最大似然分析表明，被认为是原裸子植物的贵腐属植物与其他蕨类植物属于单系簇，其中最近亲缘植物是薇菜，蕨类植物与种子植物属于单系簇，蕨类植物与种子植物属于单系簇，而蕨类植物与种子植物属于单系簇。 (3) rbcL gne研究的结果表明，现存的裸子植物是单系的而不是并系的，在买麻藤纲中，买麻藤和千岁兰彼此的亲缘关系比麻黄更为密切。