References
［1］Bedbrook，J.R.；Bogorad，L.（1976）：Endonuclease recognition sites mapped on zea mays chloroplast DNA.Proc.Natl.Acad.Sci.（USA）73，4309-4313
［2］Benzer，S.（1961）：On the topography of the genetic fine structure.Proc.Natl.Acad.Sci.（USA）47，403-416
［3］Brown，W.M.；George，M.Jr.；Wilson，A.C.（1979）：Rapid evolution of animal mitochrondrial DNA.Proc.Natl.Acad.Sci.（USA）76，1967-1971
［4］Castora，F.J.；Arnheim，N.；Simpson，M V.（1980）：Mitochondrial DNA polymorphism：evidence that variants detected by restriction enzymes differs in nucleotide sequence rather than in methylation.Proc.Natl.Acad.Sci.（USA）77，6415-6419
［5］Chen，K.；Johal，S.；Wildman，S.G.（1976）：Role of chloroplast and nuclear DNA genes during evolution of fraction 1 protein.In：Genetics and Biogenesis of Chloroplasts and Mitochondria（eds.Bucher，T.；Neupert，W.；Sebald，W.；Werner，S.），pp 3-11.Amsterdam：Elsevier North Holland Biomed.Press
［6］Goodspeed，T.H.（1954）：The genus Nicotiana.pp.283-314 Waltham，Mass.：Chronica Botanica
［7］Gray，J.C.；Kung，S.D.；Wildman，S.G.；Sheen，S.J.（1974）：Origin of Nicotiana tabacum L.detected by polypeptide composition of Fraction 1 proteins.Nature 252，226-227
［8］Helling，R.B.；Goodman，H.W.；Boyer，H.W.（1974）：An analysis of endonuclease R EcoRI fragments of DNA from lambdoid bacteriophages and other viruses by agarose-gel electrophoresis.J.Virology 14，1235-1241
［9］Herrmann，R.G.；Whitfeld，P.R.；Bottomley，W.（1980）：Construction of Sal I/PsT I restriction map of spinach chloroplast DNA using Low-gelling-temperature-agarose electrophoresis.Gene 8，179-191
［10］Jurgenson，J.E.（1980）：Nicotiana tabacum chloroplast DNA：structure and gene content，Ph D.Dissertation，Univ.Arizona
［ll］Jurgenson，J.E.；Bourque，D.P.（1981）：Mapping of rRNA genes in an inverted repeat in Nicotiana tabacum chloroplast DNA.Nucleic Acids Res.8，3505-3516
［12］Kolodner，R.；Tewari，K.K.（1975）：The molecular size and conformation of chloroplast DNA from higher plants.Biochim.Biophys.Acta 402，372-390
［13］Kung，S.D.：（1976）.Tobacco fraction 1 protein：a unique genetic marker.Science 191，429-434
［14］Kung，S.D.（1977）：Expression of chloroplast genomes in higher plants.Ann.Rev.Plant Physiol.28，401-437
［15］Kung，S.D.；Lee，C.L.；Wood，D.D.；Moscarello，M.M.（1977）：Evolutionary conservation of chloroplast genes coding for the large subunit of fraction 1 protein.Plant Physiol.60，89-94
［16］Kung，S.D.；Zhu，Y.S.；Chen K.；Shen，G.F.；Sisson V.（1981）：Nicotiana chloroplast genome Ⅱ.Chloroplast DNA alteration.Mol.Gen.Genet.183，20-24
［17］Rhodes，P.R.；Zhu，Y.S.；Kung，S.D.（1981）：Nicotiana chloroplast genome I.chloroplast DNA diversity.MoL.Gen.Genet.182，106-111(https://www.daowen.com)
［18］Rhodes，P.R.；Kung，S.D.（1981）：Chloroplast DNA isolation：Purity achieved without nuclease digestion.Can.J.Biochem.（in press）
［19］Scowcroft，W.R.（1979）：Nucleotide polymorphism in chloroplast DNA of Nicotiana debneyi，Theor.Appl.Genet.55，133-137
［20］Sugiura，M.；Kusuda，J.（1979）：Molecular cloning of tobacco chloroplast ribosomal RNA genes.Mol.Gen.Genet.172，137-141
［21］Wildman，S.G.；Lu-Liao，C.；Wong-Staal，F.（1973）：Materna linheritance，cytology，and macromolecular composition of defective chloroplasts in variegated mutant of Nicotiana tabacum.Planta 113，293-312
［22］Walbot，V.（1977）：Use of silica sol step gradients to prepare bundle sheath and mesophyll chloroplasts from Panicum maximum.Plant Physiol.60，102-108
Received May 8，1981
Communicated by D.von Wettstein
Dr.S.D.Kung
Y.S.Zhu
G.F.Shen
Department of Biological Sciences
University of Maryland
Baltimore County
Catonsville，Md.21 228（USA）
[1]S.D.Kung，Y.S.Zhu，and G.F.Shen，Department of Biological Sciences，University of Maryland，Baltimore County（UMBC）Catonsville，Md.（USA）
