| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2004: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2003: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2002: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Research Abstract |
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 mosses
We 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.
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