Abstract
Electrophoretically detectable genetic variation was used to describe the genetic structure of three South American species ofNothofagus: the widespreadN. betuloides andN. dombeyi, and the geographically restrictedN. nitida. Although the widespread species possess higher levels of genetic variation, the three species have more genetic variation within than among populations. These results are consistent with the theoretical expectations for woody, presumably highly outerossed species with wind-borne seeds.
Estimates of outcrossing rates from progeny arrays yielded slightly higher average t-values forN. nitida (1.158) andN. dombeyi (range 0.873–1.045) than forN. betuloide (0.878). Hierarchical analysis of population structure revealed values of FIS and FIT that were positive and significantly different from zero at most loci and for each species. The levels of inbreeding detected by F-statistics indicate some degree of self-fertilization and/or population substructuring into discrete family groups. Reduced seed vagility and regeneration of natural stands after disturbance by a few remnant individuals would probably generate the recruitment of related seedlings underneath parent trees.
The analysis of a putative hybrid population betweenN. nitida andN. betuloides indicated that individuals clearly segregated intonitida-like orbetuloides- like individuals. The reduced outcrossing rate ofbetuloides-like individuals from the hybrid site (t=0.585) is interpreted in concert with low pollen availability and the increased probability of selfing and/or hybridization inNothofagus.
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References
Anderson, E., 1949. Introgressive Hybridization. Wiley, N.Y.
Anderson, E., 1953. Introgressive Hybridization. Biol. Rev. Cambridge Philos. Soc. 28: 280–307.
Barber, H.N., 1970. Hybridization and the evolution of plants. Taxon 19: 154–160.
Brown, A.H.D., S.C.H. Barret & G.F. Moran, 1984. Mating system estimation in forest trees: models, methods and meanings, pp. 32–49 in Population Genetics in Forestry, Proceedings of the Meeting of the IUFRO Working Party ‘Ecological and Population Genetics’, Göttingen, edited by S. Levin. Springer-Verlag, Berlin.
Clegg, M.T., 1980. Measuring plant mating systems. Bioscience 30: 814–818.
Conkle, M.T., P.D. Hodgskiss, L.B. Nunnally & S.C. Huater, 1982. Starch gei electrophoresis of conifer seeds: a laboratory manual, Genéral technical report PSW-64. Pacific Southwest Forest and Range Experimental Station, Forest Service, U.S.D.A., Berkeley.
Crawford, D.J., 1983. Phylogenetic and systematic inferences from electrophoretic studies, pp 257–287 in Isozymes in Plant Genetics and Breeding, part A, edited by S.D. Tanksley and T.J. Orton. Elsevier Science Publishers, Amsterdam.
Cruzan, M.B., J.L. Hamrick, M.L. Arnold & B.D. Bennet, 1994. Mating system variation in hybridizing irises: effects of phenology and floral densities on family outcrossing rates. Heredity 72: 95–105.
dePamphilis, C.W. & R. Wyatt, 1990. Electrophoretic confirmation of interspecific hybridization inAesculus (Hippocastaneaceae) and the genetic structure of a broad hybrid zone. Evolution 44: 1295–1317.
Donoso, C., 1987. Variación natural en especies deNothofagus en Chile. Bosque 8: 85–97.
Donoso, C. & J. Atienza, 1983. Hibridación, natural entre especies doNothofagus siempreverdes en Chile. Bosque 1: 21–34.
Donoso, C. & J. Atienza, 1984. Hibridación natural entreNothofagus betuloides (Mirb.) Oerst.y Nothofagus nitida (Phil.)Krasser. Medio Ambiente 7: 9–16.
Gibson, J.P. & J.L. Hamriek, 1991. Genetic diversity and structure inPinus pungens (Table Mountain pine) populations. Can. J. For. Res. 21: 635–642.
Gottlieb, L.D., 1981. Electrophoretic evidence and plant populations. Progress in Phytochem. 7: 1–46.
Gottlieb, L.D., 1988. Towards molecular genetics inClarkia: gene duplications and molecular characterization of PGI genes. Ann. Missouri Bot. Gard. 75: 1169–1179.
Haase, P., 1992. Isozyme variability and biogeography ofNothofagus truncata (Fagaceae). New Zealand J. Bot. 30: 315–328.
Haase, P., 1993. Isozyme studies of New ZealandNothofagus species (southern beech) using leaf extracts. Silvae. Genet. 42: 46–51.
Haase, P., 1994. Genetic relationships and inferred evolutionary divergence in the New Zealand taxa ofNothofagus. Results from isozyme analysis. Aust. Syst. Bot. 7: 47–55.
Hamrick, J.L., M.J.W. Godt & S.L. Sherman-Broyles, 1992. Factors influencing levels of genetic diversity in woody plant species. New For. 6: 95–124.
Levin, D.A., 1975. Interspecific hybridization, heterozygosity and gene exchange inPhlox. Evolution 29: 37–51.
Levin, D.A., 1977. The organization of genetic variability inPhlox drummondii. Evolution 31: 477–494.
Li, C.C. & D.G. Horvitz, 1953. Some methods of estimating the inbreeding coefficient. Am. J. Hum. Genet. 5: 107–117.
Linhart, Y.B., J.B. Mitton, K.B. Sturgeon & M.L. Davis, 1981. Genetic variation in space and time in a population of Ponderosa pinc. Heredity 46: 407–426.
Millar, C.V., 1983. A step cline inPinus muriata. Evolution 37: 311–319.
Mitton, J. B., 1983. Conifers, pp. 443–472 in Isozymes in Plant Genetics and Breeding, Part B, edited by S.D. Tanksley and Orton. Elsevier Science Publishers. Amsterdam.
Mitton, J. B., Y.B. Linhart, K.B. Sturgeon & J.L. Hamrick, 1979. Allozyme polymorphisms detected in mature needle tissues of ponderosa pine. J. Heredity 70: 86–89.
Nei, M., 1973. Analysis of gene diversity in subdivided populations. Proc. Nat. Acad. Sci. USA 70: 3321–3323.
Nei, M., 1978. Estimation of average heterozygosity and genetic distance from a small number of individuals. Genetics 89: 583–590.
Poole, A.L., 1950. Studies of New ZealandNothofagus. I. Taxonomy and floral morphology. Trans. Roy. Soc. New Zealand 78: 363–380.
Premoli, A.C., 1994. Genetic, morphological, and ecophysiological variation in geographically restricted and widespread species ofNothofagus from southern South America. Ph.D. Thesis, University of Colorado.
Rajora, O.P., 1990. Marker allozyme genes and alleles for differentiation ofPopulus deltoides, P. Nigra, P. maximiwiczli and their interspecific hybrids. Can. J. Bot. 68: 990–998.
Rajora, O.P. & B. P. Dancik, 1992. Allozyme variation and inheritance in leaves ofPopulus deltoides, P. nigra, P. maximowiczii andP. x canadensis in comparison to those in root tips. Silvae Genet. 41: 289–292.
Ranker, T.A., C.H. Haufler, P.S. Soltis & D.E. Soltis, 1989. Genetic evidence for allopolyploidy in the neotropical fernHemionitis pinnitifida (Adiantaceae) and the reconstruction of an ancestral genome. Sys. Bot. 14: 439–447.
Rieseberg, L.H. & D.A. Warner, 1987. Electrophoretic evidence of hybridization betweenTragopogon mirus andT. miscellus (Compositae). Syst. Bot. 12: 2281–2285.
Ritland, K., 1983. Estimation of mating systems, pp. 289–302 in Isozymes in Plant Genetics and Breeding, part B, edited by S.D. Tanksley and T.J. Orton. Elsevier Science Publishers, Amsterdam.
Ritland, K. & S. Jain, 1981. A model for the estimation of outerossing rate and gene frequencies usingn independent loci. Heredity 47: 35–52.
Schemske, D.W. & R. Lande, 1985. The evolution of selffertilization and inbreeding depression in plants. II. Empirical observations. Evolution 39: 41–52.
Selander, R.K., M.H. Smith, S.Y. Yang. W.E. Johnson & J.B. Gentry, 1971. IV. Biochemical polymorphism and systematics in the genusPeromyscus. I. Variation in the old-field mouse (Peromyscus polionotus), pp. 49–90, in Studies in Genetics VI. Univ, Texas Publ. 7103.
Sokal, R.R. & F.J. Rohlf, 1981. Biometry. The Principles and Practice of Statistics in Biological Research. 2nd Edition. W.H. Freeman and Company, New York.
Soltis, D.E., C.H. Haufler, D.C. Darrow & G.J. Gastony, 1983. Starch gel electrophoresis of ferns: A compilation of grinding buffers, gel and electrode buffers, and staining schedules. Amer. Fern J. 73: 9–27.
Soltis, P.S., D.E. Soltis & L.D. Gottlieb, 1987. Phosphoglucomutase gene duplications inClarkia (Onagraceae) and their phylogenetic implications. Evolution 41: 667–671.
Stebbins, G.L., 1959. The role of hybridization in evolution. Proc. Am. Philos. Soc. 103: 231–251.
Stebbins, G.L., 1969. The significance of hybridization for plant taxonomy and evolution. Taxon 18: 26–35.
Veblen, T.T. & D.H. Ashton, 1978. Catastrophic influences on the vegetation of the Valdivian Andes, Chile. Vegetatlo 36: 147–167.
Veblen, T.T. & D.C. Lorenz, 1987. Post-fire stand development ofAustrocedrus-Nothofagus forests in northern Patagonia. Vegetatio 71: 113–126.
Veblen, T.T., C. Donoso, T. Kitzberger & A.J. Rebertus. Ecology of southern Chilean and ArgentineanNothofagus forests, in Ecology and Biogeography ofNothofagus forests, edited by T.T. Veblen, R.S. Hill and J. Read. Yale University Press. In press.
Wardle, J.A., 1984. The New Zealand Beches, New Zealand Forest Service.
Weir, B.S., 1990. Genetic Data Analysis. Sinauer Associates, Inc. Publishers, Sunderland, Massachusetts.
Werth, C.R., S.I. Guttman & W.H. Eshbaugh, 1985. Electrophoretic evidence of reticulate evolution in the AppalachianAsplenium complex. Syst. Bot. 10: 184–192.
Wheeler, N.C. & R.P. Guries, 1987. A quantitative measure of introgression between lodgepole and jack pines. Can. J. Bot. 65: 1876–1885.
Whittham, T.G., P.A. Morrow & B.M. Potts, 1991. Conservation of hybrid plants. Science 254: 779–780.
Workman, P.L. & J.D. Niswander, 1970. Population studies on Southwestern Indians. II. Local genetic differentiation in the Papago. Amer. J. Human Genet. 22: 24–49.
Wright, S., 1965. The interpretation of population structure by F-statistics with special regard to systems of mating. Evolution 19: 395–420.
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Premoli, A.C. Allozyme polymorphisms, outerossing rates, and hybridization of South AmericanNothofagus . Genetica 97, 55–64 (1996). https://doi.org/10.1007/BF00132581
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DOI: https://doi.org/10.1007/BF00132581