| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2003: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2002: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Research Abstract |
Seedling populations following the monocarpic mass flowering of Sasa jotanii in the Mikurajima Island in 1997, regenerating culms and unflowered clump on the Mt. Oyama were analyzed on the genetic aspect of the mass flowering using rice microsatellite DNA loci in comparison with three sterile populations on Mt. Miharayama, Hachijojima Island. Four microsatellite loci, R230, RM205, RM254 and RM60 were used for the analyses with respect to the occurrence of multi-locus genes of A, B, C and D, respectively. A total of 50 sample DNAs including three from an unflowered clump (UF), 13 regenerating culms (RC), eight vicinal seedlings to the RC (VS), six non-nearest neighbour seedlings from the RC (NN), four culms from Mt. Nagataki (NG) and 16 from Hachijojima Island (HA) were used as the template.
Occurrence of all alleles of A, B, C and D were limited on the populations or culms of Isl. Mikurajima, while none in Hachijojima. Three scattered populations on Mt. Miharayama, Isl. Hachijojima had poor and almost the same genetic diversity suggested that the populations originated from one continuous population in old ages. Among the Mikurajima populations, three out of four samples of NG that located on 1 km south-east from Mt. Oyama had none allelic loci like as the HA populations. Co-occurrence of A, B and C was found only in RC and VS with similar genetic frequencies, whereas A was not found in NN. The unflowered clump composed of six aggregated culms, among which one UF had only allele A, while two had none showed the clump was composed of more than two clones that originated from distinct genets.
These results suggests that a combination of genes such as alleles A, B and C induce the monocarpic mass flowering and death, while the latter will be independent from the former and that controlled by A as a leaky of a lethal gene.
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