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Self-fertilization and absence of heterozygotes in Hordeurn euclaston (Gramineae)

Carlos Alexandre Sanchez Ferreira; Suzana Cavalli-Molina

Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, prédio 43323, Caixa Postal 15053, 91501-970 Porto Alegre, RS, Brasil. Send correspondence to C.A.S.F.

ABSTRACT

Isoenzymes of Hordeum euclaston were analyzed by horizontal polyacrylamide gel electrophoresis. Four isoenzymatic systems were assayed in seedlings grown from seeds of 95 plants from three wild populations from Southern Brazil. The mode of reproduction was determined by analyzing progenies of several maternal plants in each population. Out of 26 loci observed, six were polymorphic, with a total of 34 alleles. No genetic variation was detected within any single plant progeny. No heterozygosity was found in the wild populations. The results show low genetic variation between plants within populations. Low interpopulational differentiation was also found, contrary to the theoretical prediction according to which different self-fertilizing populations are very different in genetic constitution.

Keywords: self-fertilization; heterozygotes; Hordeurn euclaston.

REFERENCES

Babbel, G.R. and Wain, R.P. (1977). Genetic structure of Hordeum jubatum. I. Outcrossing rates and heterozygosity levels. Can. J. Genet. Cytol. 19: 143-152.

Bothmer, R. von ( 1987). Natural variation, phylogeny and genetic resources in Hordeum. In: Barley Genet. Proceedings of the 5th International Barley Genetic Symposium (Yasuda, S. and Korishi, T., eds.). Okayama, 6-11 October 1986, Sanyo Press Co., Ltd., Okayama, PP. 23-33.

Bothmer, R. von aid Jacobsen, N. (1985). Wild species of Hordeum in Argentina and Chile. Geogr. Tidsskrift 80: 18-21.

Bothmer, R. von, Jacobsen, N., Jorgensen, R.B. and Nicora, E. (1982). Revision of the Hordeum pusillum group. Nordic Journal of Botany 2: 307-321.

Brewer, G.J. (1970). An Introduction to Isozyme Techniques. Academic Press, New York, pp. 82-84,115-117.

Brown, A.H.D. (1983). Barley. In: Isozymes in Plant Genetics and Breeding (Tanksley, S.D. and Orton, T.J., eds.). Part B. Elsevier Science Publishers B.V., Amsterdam, pp. 57-77.

Brown, A.H.D., Zohary, D. and Nevo, E. (1978). Outcrossing rates and heterozygosity in natural populations of Hordeum spontaneum Koch in Israel. Heredity 41: 49-62.

Eggers, L. and Boldrini, I.I. (1988). Espécies silvestres do gênero Hordeum L. (Gramineae) ocorrentes no Estado do Rio Grande do Sul. Inheringia. Ser. Bot. (37): 71-87.

Fedak, G.V. (1985). Wide crosses in Hordeum. In: Barley. ASA Mono. 26. Am. Soc. Agron., Madison, WI, pp. 155-186.

Feuerstein, U., Brown, A.H.D. and Burdon, J.J. (1990). Linkage of the rust resistance genes from wild barley (Hordeum spontaneum) with isozyme markers. Plant Breeding 104: 318-324.

Giles, B.E. and Bothmer, R. von (1985). The progenitor of barley (Hordeum vulgare L. ssp. spontaneum) - its importance as a gene resource. Svenges Utsodesforenings Tidskeift 5: 53-61.

Hamrick, J.L. (1979). Genetic variation and longevity. In: Topics in Plant Population Biology (Solbrig, O.T., Jain, S., Johnson, G.B. and Raven, P.H., eds.). Columbia University Press, New York, pp. 84-113.

Levin, D.A. and Wilson, A.C. (1976). Rates of evolution in seed plants: net increase in diversity of chromosome numbers and species numbers through time. Proc. Natl. Acad. Sci. USA 73:1089-1091.

Nei, M. (1972). Genetic distance between populations. The American Naturalist 106: 283-292.

Roose, M.L. and Gottlieb, L.D. (1976). Genetic and biochemical consequences of polyploidy in Trogopogon. Evolution 30: 818-830.

Scandalios, J.G. (1969). Genetic control of multiple molecular forms of enzymes in plants: a review. Biochemical Genetics 3: 37-79.

Stebbins, G.L. (1974). Flowering Plants: Evolution above the Species Level. Belknap Press, Cambridge, pp. 68-101.

Vallejos, E. (1983). Enzyme activity staining. In: Isozymes and Plant Genetics and Breeding. Part A. (Tanksley, S.D. and Orton, T.J., eds.). Elsevier Science Publisher B.V. Amsterdam, pp. 469-516.

Weir, B.S., Allard, R.W. and Kahler, A.L. (1972). Analysis of complex allozyme polymorphisms in a barley population. Genetics 72: 505-523.