New Forests 19: 109–114, 2000. © 2000 Kluwer Academic Publishers. Printed in the Netherlands. Research note Analysis of mitochondrial DNA of an endangered beech species, Fagus hayatae Palibin ex Hayata SUMIE KATO 1 , TAKAYOSHI KOIKE 1 , THOMAS T. LEI 2 , CHANG-FU HSIEH 3 , KUNIHIKO UEDA 4 and TETSUO MIKAMI 1∗ 1 Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan; 2 Department of Biology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060, USA; 3 Department of Botany, National TaiwanUniversity, Taipei 106, Taiwan; 4 Faculty of Science, Kanazawa University, Kanazawa 920-11, Japan ( ∗ author for correspondence) Received 25 January 1999; accepted 14 June 1999 Key words. chondriome type, cytoplasmic diversity, phylogenetic relationships, restriction fragment length polymorphisms, Southern hybridization Abstract. Mitochondrial DNA restriction fragment length polymorphisms were used to examine cytoplasmic diversity within a relic-like population of Fagus hayatae, located in northern Taiwan. Fifteen trees were surveyed for three restriction endonucleases (BamHI, EcoRI and HindIII) and five mitochondrial gene probes (atpA, atp6, atp9, coxI and coxII). The analysis failed to reveal any polymorphisms, an observation that suggests cytoplasmic uniformity in the F. hayatae population examined. It is also interesting to note that the chondriome type of our F. hayatae samples is very close to that characteristic of F. crenata populations in the southernmost area of Japan. Introduction The genus Fagus comprises two subgenera, Engleriana and Fagus, with the latter further subdivided into four sections: Grandifolia, Longipetiolata, Lucida and Fagus (Shen 1992, Peters 1997). Some members of the genus have received much attention in silviculture because they fulfill a wide spectrum of economic and environmental functions. F. hayatae Palibin ex Hayata is grouped in the section Lucida, together with F. crenata Blume, F. lucida Rehder et Wilson (occurs in southern China), and F. chienii Cheng (found in western China), and is an example of a relic tree species with a very limited distribution and in a state of regression (Hsieh 1989). It occurs only in a few locations in northern Taiwan and southern China (Hsieh 1989; Peters 1997). Knowledge of the genetic variation of this