| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 1998: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1997: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Research Abstract |
Data of molecular phylogenetic studies are rapidly published for various plant groups, and are now requiring drastic changes of the systematic position of quite a few taxa. This research project has attempted to evaluate results of molecular studies by means of morphology-based evidence, I.e., embryological study particularly with respect to Asterales. Besides, in view of increasing information of molecular data for various plant groups, I have also worked with Crotonoideae and Drypeteae (Euphorbiaceae), Setchellanthus (position uncertain till recent time), Takhtajania (Winteraceae).
Results of this research project are summarized as follows. In Crotonoideae, in contrast to other genera, six genera including Adenocline have a thin inner integument destitute of vascular bundles. Compared to outgroup, in agreement with results of molecular studies, the six genera are likely to be positioned basal in an evolutionary line of the subfamily. Drypeteae, traditionally placed in Phyllanthoideae (Euphorbiaceae), have a fibrous exotegmen, an endothelium, and a thick inner integument, and a combination of these features indicates that Drypeteae are no longer placed in Phyllanthoideae and rather he transferred to a position near Erythroxylaceae and Rhizophoraceae. This conclusion agrees with that from molecular evidence. Setchellanthus, whose systematic position had been uncertain, was found to have straight seeds with a spathulate embryo and a non-fibrous exotegmen and suggested to be positioned near-basal to the core Capparales. The position fits in with that suggested by molecular evidence. Argophyllum and Corokia of Argophyllaceae (Asterales) have embryological features suitable to Asterales as suggested by molecular evidence.
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