| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1997: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1996: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Research Abstract |
In order to clarify phylogenetic relationships between East Asian diploid species of Taraxacum, isozyme analysis was carried out. Each 30 plants from 19 populations of the following species were sampled and enzyme electrophoresis was made ; T.formosanum (5 pops. from Taiwan), T.japonicum (5pops. from west Japan), T.platycarpum ssp. maruyamanum (2 pops.frpm Isl.Oki), ssp. hondoense (5 pops from east Japan) and ssp. platycarpum (2pops.from east Japan). Genetic distances were culculated and a UPGMA tree was constructed by means of PHYLIP.Four clades were recognized as follows ; 1) Formosanum clade, 2) Japonicum clade, 3) maruyamanum clade and 4) other Platycarpum clade. Of these Formosanum clade is the most remote from other clades and Japonicum clade is firstly branched off among the Japanese populations.
Origin of pentaploid agamospermous species Taraxacum albidum was also studied electro-phoretically. The present species is uniclonal and of hybrid origin (Menken & Morita, 1990). Under the hypothesis that a reduced egg cell of a diploid plant fertilized by unreduced pollen of a tetraploid plant produced pentaploid T.albidum, East-Asian tetraploids were studied. One necessary condition of the candidate of pollen parent is that it must possess isozyme alleles, skdh-d and mdh-c which are shared by T.albidum but never found in the Japanese diploid species. Another criterion is that is does not possess the alleles which are not found in T.albidun. Among 7 tetraploid species examined, T.hideoi and T.coreanum satisfied the first criterion but only T.coreanum did the second criterion, because the former species possess g-allele of 6 gdh-2 which are not possessed by T.albidum. It was also clarified in this study that T.coreanum grows in northern Kyushu, Japan. The seed parent of T.albidum was difined to be T.japonicum, because only this species shares c-asllele of pgi-1 with T.albidum among the Japanese diploid dandelions.
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