Species diversity in haploid dominat plant species-research on the inter-relationship between speciation and morphological diversification

苔藓植物具有配子体优势的生活史，在陆地植物中是独特的。因此，基因型的任何突变变化都直接表现为表型表达。根据这个顺序，我们在这个项目中进行了以下两项研究：1。短句来源对分布广泛的藓类Dixonia thamnioides进行了遗传和形态学分析，发现在空间不相交的局部种群中，尽管形态存在差异，但遗传多样性很小。肝细胞形态进化与染色体变化在物种形成中的作用研究。本研究使用的是海苔菌复合体。众所周知，多毛蝶具有单倍体、二倍体和三倍体变异，并被认为是一个在形态特征上有广泛差异的单一物种。通过形态学、染色体数目、12个位点的同工酶图谱以及rbcL与atpB间互编码区的分子证据分析，揭示了以下事实：(1)在单倍体中，存在11个以上的“种”，遗传距离大于0.3。这些“物种”不仅具有独特的形态特征，而且可以通过atpB- rbcL序列的差异来区分。有趣的是，在日本人群中，二倍体和三倍体与单倍体具有不同的遗传特征，因此可能不会从单倍体祖先那里获得简单的染色体重复。二倍体和三倍体是异源多倍体这一事实也支持了这一假设。目前所知的唯一例外是夏威夷岛的二倍体，它们是自倍体，在每个位点上共享所有等位基因。

Bryophytes have gametophyte-dominant life history and thus are unique among land plants. As a result, any changes in genotypes by mutation directly appear as phenotype expression. In this sequence, we conducted the following two researches in this project :1. Evolution of morphological features and its contribution on speciation in mossesWe conducted genetical and morphological analyses on the very rare, widely distributed moss species, Dixonia thamnioides, and knew that there was only a little genetical diversification in spite of morphological variation among spatially disjunct local populations.2. Investigation on the role of morphological evolution in speciation in hepatics, along with chromosomal changes.We conducted this research using Dumortiera hirusta complex. Dumortiera hirsuta has been known with its mono-, di-, and tri-ploids variants and have been treated as comprising a single species with wide variation in morphological features. Analyses on morphology, chromosome numbers, allozyme patterns with 12 loci, and molecular evidence of intercoding region between rbcL and atpB revealed the following facts :(1)Among monoploids, there exist more than eleven "species", recognizing with genetic distance more than 0.3.Each of these "species" not only has unique morphological features, but also can be distinguished by atpB- rbcL sequence differences. It is interesting that among Japanese populations di- and tri-ploids have different genetical features from monoploids and thus may not derived simple duplication of chromosome from monoploid ancestor. This hypothesis also supported by the fact that di- and tri-ploids are allopolyploid. The single exception as far as known is the diploids of Hawaii Island, which are autoploid and share all alleles in every loci.