Speciation of Eupatorium in southwestern North America

• Project/Area Number: 63041048
• Research Category: Grant-in-Aid for Overseas Scientific Survey.
• Allocation Type: Single-year Grants
• Section: Field Research
• Research Institution: University of Tokyo
• Principal Investigator: YAHARA T. Botanical Gardens, University of Tokyo, 理学部, 講師 (90158048)
• Co-Investigator(Kenkyū-buntansha): CRAWFORD D.J. Ohio State University, 教授 ; 伊藤 元己 東京都立大学, 理学部, 助手 (00193524) ; 渡辺 邦秋 神戸大学, 教養部, 助教授 (80031376) ; WATANABE K. Kobe University ; ITO M. Tokyo Metropolitan University
• Project Period (FY): 1988 – 1989
• Project Status: Completed (Fiscal Year 1989)
• Budget Amount: ¥6,200,000 (Direct Cost: ¥6,200,000); Fiscal Year 1989: ¥1,200,000 (Direct Cost: ¥1,200,000); Fiscal Year 1988: ¥5,000,000 (Direct Cost: ¥5,000,000)
• Keywords: Agamospermy / chloroplast DNA / Compositae / Eupatorium / Isozyme / Karyotype / Polyploidy / Sexual reproduction

Research Abstract

1.Eupatorium is an interesting plant group because many species include sexual and agamospermous races. To elucidate the cause for the dichotomous evolution of reproductive system, heterozygosities were compared between sexual and agamospermuos races of E. altissimum and E. cuneifolium. Both sexual and agamospermous races showed very low genetic heterozygosities and there was no significant difference between them. These results suggest that not heterozygosity but reproductive rate is the major cause for the evolution of the reproductive system.
2.Phylogenetic relationships among 23 spp. of North American Eupatorium were examined using enzyme electrophoresis, RFLP of chloroplast DNA, and chromosomal similarity. A new method to quantify chromosomal similarity is developped. The results confirmed three distinct groups which are morphologically distinct.

Research Products

• [Publications] Yahara,T.: "Evolution of agamospermous races in Boehmeria and Eupatorium" Plant Species Biology. 5. (1990)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Watanabe K et al.: "Numerical analyses of karyotypic diversity in the genus Eupatorium(Compositae,Eupatorieae)" Plant Systematic and Evolution. (1990)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Yahara, T.: "Evolution of agamospermous races in Boehmeria and Eupatorium" Plant Species Biology. 5. (1990)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Watanabe, K., Ito, M., Yahara, T., Sullivan, V.I., Kawahara, T., and Crawford, D.J.: "Numerical analyses of karyotypic diversity in the genus Eupatorium (Compositae, Eupatorieae)." Plant Systematics and Evolution.
  • Description: 「研究成果報告書概要(欧文)」より