Maintenance of Genetic Variation in Plant Populations

  • R. A. Ennos


The presence of genetic variation within populations is a prerequisite for adaptation and evolutionary change. All genetic variation is ultimately generated through mutation. If a mutation has no effect on the fitness of individuals, the frequency of the mutant in the population will be determined by stochastic factors [a subject thoroughly dealt with by Wright (1969)]. On the other hand, where significant amounts of genetic variation affecting fitness are found in natural populations, a selective explanation for the maintenance of this variation must be sought.


Plant Population White Clover Crown Rust Meiotic Drive Random Mating Population 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Allard, R. W., 1975, The mating system and microevolution, Genetics 79:115–126.PubMedGoogle Scholar
  2. Allard, R. W., and Adams, J., 1969, Population studies in predominantly self pollinating species. XIII. Intergenotypic competition and population structure in barley and wheat. Am. Nat. 103:621–645.Google Scholar
  3. Allard, R. W., and Workman, P. L., 1963, Population studies in predominantly self pollinating species. IV. Seasonal fluctuations in estimated values of genetic parameters in lima bean populations, Evolution 18:470–480.Google Scholar
  4. Allard, R. W., Jain, S. K., and Workman, P. L., 1968, Genetics of inbreeding populations, Adv. Genet. 14:55–131.Google Scholar
  5. Allard, R. W., Kahler, A. L., and Weir, B. S., 1972, The effect of selection on esterase allozymes in a barley population, Genetics 72:489–503.PubMedGoogle Scholar
  6. Antonovics, J., 1968, Evolution in closely adjacent plant populations VI. Manifold effects of gene flow, Heredity 23:507–524.Google Scholar
  7. Antonovics, J., 1978, The population genetics of mixtures, in: Plant Relations in Pasture (J. R. Wilson, ed.), CSIRO, Melbourne, Australia.Google Scholar
  8. Antonovics, J., and Bradshaw, A. D., 1970, Evolution in closely adjacent plant populations. VIII. Clinal patterns at a mine boundary, Heredity 25:349–362.Google Scholar
  9. Aston, J. L., and Bradshaw, A. D., 1966, Evolution in closely adjacent plant populations. II. Agrostis stolonifera in maritime habitats, Heredity 21:649–664.Google Scholar
  10. Atwood, S. S., 1944, Oppositional alleles in natural populations of Trifolium repens, Genetics 29:428–435.PubMedGoogle Scholar
  11. Barber, H. N., 1965, Selection in natural populations, Heredity 20:551–572.Google Scholar
  12. Bennett, J. H., and Binet, F. E., 1956, Association between Mendelian factors with mixed selling and random mating, Heredity 10:51–56.Google Scholar
  13. Berris, W. P., 1959, Selective fertilisation in lima beans, Genetics 44:555–562.Google Scholar
  14. Bishop, J. A., 1972, An experimental study of the cline of industrial melanism in Biston betularia (L) (Lepidoptera) between urban Liverpool and North Wales, J. Anim. Ecol. 41:209–243.Google Scholar
  15. Bradshaw, A. D., 1972, Some of the evolutionary consequences of being a plant, Evol. Biol. 5:25–47.Google Scholar
  16. Brewbaker, J. L., 1955, V leaf markings of white clover, J. Hered. 46:115–123.Google Scholar
  17. Brown, A. H. D., 1979, Enzyme polymorphisms in plant populations, Theor. Popul. Biol. 15:1–42.Google Scholar
  18. Brown, A. H. D., Marshall, D. R., and Albrecht, L., 1974, The maintenance of alcohol dehydrogenase polymorphism in Bromus mollis L., Aust. J. Biol. Sci. 29:389–396.Google Scholar
  19. Brown, A. D. H., Zohary, D., and Nevo, E., 1978, Outcrossing rates and heterozygosity in natural populations of Hordeurn spontaneum, Koch, in Israel, Heredity 41:49–62.Google Scholar
  20. Burdon, J. J., and Marshall, D. R., 1981, Biological control and the reproductive mode of weeds, J. Appl. Ecol. 18:649–658.Google Scholar
  21. Cahn, M. A., 1976, The biology of leaf mark polymorphism in Trifolium repens, 2. Evidence for the selection of marks by rumen fistulated sheep, Heredity 37:327–334.Google Scholar
  22. Campbell, J. M., and Lawrence, M. J., 1981, The population genetics of the self-incom-patability polymorphism in Papaver rhoeas. 1. The number and distribution of s-alleles in families from three localities, Heredity 46:69–79.Google Scholar
  23. Carey, K., and Ganders, F. R., 1980, Heterozygous advantage at the fruit wing locus in Plectritis congesta (Valerianaceae), Evolution 34:601–607.Google Scholar
  24. Carlson, W. R., 1969, Factors affecting preferential fertilisation in maize. Genetics 62:543–554.PubMedGoogle Scholar
  25. Charles, A. H., 1964, Differential survival of plant types in swards, J. Br. Grassl. Soc. 19:198–204.Google Scholar
  26. Clarke, B., 1962, Balanced polymorphism and the diversity of sympatric species, in: Taxonomy and Geography, Vol. 4 (D. Nichols, ed.). pp. 47–70, Systematics Association Publication No. 4, London.Google Scholar
  27. Clarke, B., 1976, The ecological genetics of host-parasite relationships in Genetic Aspects of Host-Parasite Relationships (A. E. R. Taylor and R. Muller, eds.), pp. 87–103, Blackwell, London.Google Scholar
  28. Clegg, M. T., and Allard, R. W., 1973, Viability versus fecundity selection in slender wild oats, Arena barbata, Science 181:667–668.PubMedGoogle Scholar
  29. Clegg, M. T., Kahler, A. L., and Allard, R. W., 1978c, Estimation of life cycle components of selection in an experimental plant population, Genetics 89:765–795.PubMedGoogle Scholar
  30. Clegg, M. T., Kahler, A. L., and Allard, R. W., 1978b, Genetic demography of plant populations, in: Genetics and Ecology: The Interphase (P. M. Bussard, ed.), Springer Verlag, Berlin.Google Scholar
  31. Cockerham, C. C., and Burrows, P. M., 1971, Populations of interacting autogenous components, Am. Nat. 105:13–29.Google Scholar
  32. Cockerham, C. C., and Rawlings, J. O., 1967, Apparent heterosis of a neutral gene with inbreeding, Cien. Cult. 19:89–94.Google Scholar
  33. Cockerham, C. C., Burrows, P. M., Young, S. S., and Prout, T., 1972, Frequency dependent selection in randomly mating populations, Am. Nat. 106:493–515.Google Scholar
  34. Cook, S. A., 1962, Genetic system, variation, and adaptation in Eschyscholzia califomica, Evolution 16:278–299.Google Scholar
  35. Daday, H., 1954a, Gene frequencies in wild populations of Trifolium repens. I. Distribution by latitude, Heredity 8:61–78.Google Scholar
  36. Daday, H., 1954b, Gene frequencies in wild populations of Trifolium repens II. Distribution by altitude, Heredity 8:377–384.Google Scholar
  37. Davies, M. S., and Snaydon, R. W., 1976, Rapid population differentiation in a mosaic environment. III. Coefficients of selection. Heredity 36:59–66.Google Scholar
  38. Dempster, E. R., 1955, Maintenance of genetic heterogeneity, Cold Spring Harbor Symposium 20:25–32.Google Scholar
  39. de Wit, C. T., 1960, On competition, Versl. Landbouwkd. Onderz. 66:1–82.Google Scholar
  40. Dickinson, H., and Antonovics, J., 1973a, Theoretical consequences of sympatric divergence, Am. Nat. 107:256–274.Google Scholar
  41. Dickinson, H., and Antonovics, J., 1973b, The effect of environmental heterogeneity on the genetics of finite populations. Genetics 73:713–735.PubMedGoogle Scholar
  42. Dinoor, A., 1975, Evaluation of sources of disease resistance, in: Crop genetic resources for today and tomorrow O. H. Frankel and J. G. Hawkes, eds.), p. 201, Cambridge University Press, Cambridge.Google Scholar
  43. Dinoor, A., 1977, Oat crown rust in Israel, Ann. N. Y. Acad. Sci. 287:357–366.Google Scholar
  44. Dinoor, A., and Wahl, I., 1963, Reaction of non-cultivated oats from Israel to Canadian races of crown rust and stem rust, Can. J. Plant Sci. 43:263–270.Google Scholar
  45. Dollinger, P. M., Ehrlich, P. R., Fitch, W. L., and Breedlove, D. E., 1973, Alkaloid and predation patterns in Colorado lupine populations, Oecologia 13:191–204.Google Scholar
  46. East, E. M., and Mangelsdorf, A. J., 1925, A new interpretation of the hereditary behaviour of self sterile plants. Proc. Natl. Acad. Sci. USA 11:166–183.PubMedGoogle Scholar
  47. Edmunds, G. F., and Alstad, D. N., 1978, Coevolution in herbivores and conifers, Science 199:941–945.PubMedGoogle Scholar
  48. Ehrlich, P. R., and Raven, P. H., 1969, Differentiation of populations, Science 165:1228–1232.PubMedGoogle Scholar
  49. Ellingboe, A. H., 1981, Changing concepts in host-pathogen genetics, Annu. Rev. Phytopathol. 19:125–143.Google Scholar
  50. Emerson, S., 1938, The genetics of self incompatability in Oenothera organensis, Genetics 23:190–202.PubMedGoogle Scholar
  51. Endler, J. A., 1977, Geographic Variation, Speciation and Clines, Princeton University Press, Princeton, New Jersey.Google Scholar
  52. Ennos, R. A., 1981, Manifold effects of the cyanogenic loci in white clover, Heredity 46:127–132.Google Scholar
  53. Ewens, W. J., 1964, On the question of self sterility alleles, Genetics 50:1433–1438.PubMedGoogle Scholar
  54. Finney, D. J., 1952, The equilibrium of a self-incompatible polymorphic species, Genetica 26:33–64.PubMedGoogle Scholar
  55. Fisher, R. A., 1930, The Genetical Theory of Natural Selection, Clarendon, Oxford.Google Scholar
  56. Fisher, R. A., and Mather, K., 1943, The inheritance of style length in Lythrum salicaria, Ann. Eugen. 12:1–23.Google Scholar
  57. Flor, H. H., 1956, The complementary genic systems in flax and flax rust, Adv. Genet. 8:29–54.Google Scholar
  58. Ganders, F. R., Carey, K., and Griffiths, A. J. F., 1977, Natural selection for a fruit dimorphism in Plectritis conges ta (Valerianaceae), Evolution 31:873–881.Google Scholar
  59. Gillett, J. T., 1962, Pest pressure, an underestimated factor in evolution, in: Taxonomy and Geography, Vol. 4 (D. Nichols, ed.), pp. 37–46, Systematics Association, Publication No. 4, London.Google Scholar
  60. Gliddon, C., and Strobeck, C., 1975, Necessary and sufficient conditions for multiple niche polymorphism in haploids, Am. Nat. 109:233–235.Google Scholar
  61. Griffiths, D. J., 1950, The liability of seed crops of perennial ryegrass (Lolium perenne) to contamination by wind born pollen, J. Agric. Sci. 40:19–38.Google Scholar
  62. Gustafsson, A., Nyborn, N., von Wettstein, U., 1950, Chlorophyll factors and heterosis in barley, Hereditas 36:383–392.Google Scholar
  63. Haldane, J. B. S., 1936, Some natural populations of Lythrum salicaria, J. Genet. 32:393–397.Google Scholar
  64. Haldane, J. B. S., and Jayakar, S. D., 1963, Polymorphism due to selection of varying directions, J. Genet. 58:237–242.Google Scholar
  65. Hamrick, J. L., and Allard, R. W., 1972, Microgeographic variation in allozyme frequencies in Avena barbata, Proc. Natl. Acad. Sci. USA 69:2100–2104.PubMedGoogle Scholar
  66. Hamrick, J. L., and Holden, L. R., 1979, Influence of microhabitat heterogeneity on gene frequency distribution and gametic phase disequilibrium in Avena barbata, Evolution 33:521–533.Google Scholar
  67. Harberd, D. J., 1963, Observations on natural clones of Trifolium repens L., New Phytol. 62:198–204.Google Scholar
  68. Harding, J., 1970, Genetics of Lupinus II. The selective disadvantage of the pink flowered colour mutant in Lupinus nanus, Evolution 24:120–127.Google Scholar
  69. Harding, J., 1975, Models for gamete competition and self fertilisation as components of natural selection in populations of higher plants, in: Gamete Competition in Plants and Animals (D. L. Mulcahy, ed.), North-Holland, Amsterdam, and American Elsevier, New York.Google Scholar
  70. Harding, J., and Barnes, K., 1977, Genetics of Lupinus X. Genetic variability, heterozygosity, and outcrossing in colonial populations of Lupinus succulentus, Evolution 31:247–255.Google Scholar
  71. Harlan, J. R., 1976, Diseases as a factor in plant evolution, Annu. Rev. Phytopathol. 14:31–51.Google Scholar
  72. Harper, J. L., 1969, The role of predation in vegetational diversity, in: Diversity and Stability in Ecological Systems, Brookhaven Symposium in Biology, Vol. 22. pp. 48–62. Brook-haven National Laboratory. New York.Google Scholar
  73. Harper, J. L., 1977, Population Biology of Plants. Academic. London.Google Scholar
  74. Hartl, D. L., 1970, Analysis of a general population genetic model of meiotic drive. Evolution 24:538–545.Google Scholar
  75. Hartl, D. L., 1975. Stochastic selection of gametes and zygotes. in: Gamete Competition in Plants and Animals, (D. L. Mulcahy, ed.), North-Holland. Amsterdam, and American Elsevier, New York.Google Scholar
  76. Hartl, D. L., 1979, Selection for serotiny in lodgepole pine: Mathematical analysis of the model of Perry and Lotan, Evolution 33:969–972.Google Scholar
  77. Hartl, D. L., and Cook, R. D., 1973, Balanced polymorphism of quasineutral alleles, Theor. Popul. Biol. 4:163–172.Google Scholar
  78. Hayman, D. I., 1953, Mixed selfing and random mating when homozygotes are at a disadvantage, Heredity 7:185–192.Google Scholar
  79. Hedrick, P. W., 1974, Genetic variation in a heterogeneous environment I. Temporal heterogeneity and the absolute dominance model, Genetics 78:757–770.PubMedGoogle Scholar
  80. Hedrick, P. W., 1976, Genetic variation in a heterogeneous environment. II. Temporal heterogeneity and directional selection, Genetics 84:145–157.PubMedGoogle Scholar
  81. Heuch, I., 1979, Equilibrium populations of heterostylous plants, Theor. Popul. Biol. 15:43–57.Google Scholar
  82. Hoekstra, R. F., 1975, A deterministic model of cyclical selection, Genet. Res. 25:1–15.PubMedGoogle Scholar
  83. Horovitz, A., and Harding, J., 1972, The concept of male outcrossing in hermaphrodite higher plants, Heredity 29:223–236.Google Scholar
  84. Imam, A. G., and Allard, R. W., 1965, Population studies in predominantly self pollinating species VI. Genetic variability between and within natural populations of wild oats from differing habitats in California, Genetics 51:49–62.PubMedGoogle Scholar
  85. Jain, S. K., 1975, Gametic selection in mixed selfing and random mating plant populations, in: Gamete Competition in Plants and Animals (D. L. Mulcahy, ed.), North-Holland, Amsterdam and American Elsevier, New York.Google Scholar
  86. Jain, S. K., and Allard, R. W., 1960, Population studies in predominantly self pollinating species. I. Evidence for heterozygous advantage in a closed population of barley. Proc. Natl. Acad. Sci. USA 46:1371–1377.PubMedGoogle Scholar
  87. Jain, S. K., and Bradshaw, A. D., 1966, Evolutionary divergence among adjacent plant populations. I. The evidence and its theoretical analysis, Heredity 21:407–441.Google Scholar
  88. Jain, S. K., Marshall, D. R., and Wu, K., 1970, Genetic variability in natural populations of softchess (Bromus mollis L), Evolution 24:649–659.Google Scholar
  89. Jayakar, S. D., 1970, A mathematical model of gene frequencies in a parasite and its host, Theor. Popul. Biol. 1:140–164.PubMedGoogle Scholar
  90. Jones, D. A., 1972, On the polymorphism of cyanogenesis in Lotus corniculatus L. IV. The Netherlands, Genetica 43:394–406.Google Scholar
  91. Jones, D. F., 1928, Selective Fertilisation, University of Chicago Press, Chicago, Illinois.Google Scholar
  92. Kahn, M. A., Putwain, R. D., and Bradshaw, A. D., 1975, Population interrelationships 2. Frequency-dependent fitness in Linum, Heredity 34:145–163.Google Scholar
  93. Kannenberg, L. W., and Allard, R. W., 1967, Population studies in predominantly self pollinating species. VIII. Genetic variability in the Festuca microstachys complex, Evolution 21:227–240.Google Scholar
  94. Karlin, S., 1976, Population subdivision and selection migration interaction, in: Population Genetics and Ecology (S. Karlin and E. Nevo, eds.), pp. 617–657, Academic, New York.Google Scholar
  95. Karlin, S., and Feldman, M. W., 1968, Further analysis of negative assortative mating, Genetics 59:117–136.PubMedGoogle Scholar
  96. Karlin, S., and Lieberman, U., 1974, Random variation in selection intensities: Case of large population size, Theor. Popul. Biol. 6:355–382.PubMedGoogle Scholar
  97. Karlin, S., and Richter-Dyn, N., 1976, Some theoretical analyses of migration selection interaction in a cline: A generalised two range environment, in: Population Genetics and Ecology, (S. Karlin and E. Nevo, eds.), pp. 659–700, Academic, New York.Google Scholar
  98. Kay, Q. O. N., 1976, Preferential pollination in yellow-flowered morphs of Raphanus ra-phanistrum by Pieris and Eristalis spp., Nature 261:230–232.Google Scholar
  99. Kiang, Y. T., and Libby, W. J., 1972, Maintenance of a lethal in a natural population of Mimulus guttatus, Am. Nat. 106:351–367.Google Scholar
  100. Kimura, M., and Kayano, H., 1961, The maintenance of supernumary chromosomes in wild populations of Lilium callosum by preferential segregation, Genetics 46:1699–1712.PubMedGoogle Scholar
  101. Leonard, K. J., 1969, Selection in heterogeneous populations of Puccinia graminis f. sp. avenae, Phytopathology 59:1851–1857.Google Scholar
  102. Leonard, K. J., 1977, Selection pressures and plant pathogens, Ann. N.Y. Acad. Sci. 287:207–222.Google Scholar
  103. Leonard, K. J., and Czochor, R. J., 1980, Theory of genetic interactions among populations of plants and their pathogens, Annu. Rev. Phytopathol. 18:237–258.Google Scholar
  104. Levene, H., 1953, Genetic equilibrium where more than one niche is available, Am. Nat. 87:331–333.Google Scholar
  105. Levin, D. A., 1972, Low frequency disadvantage in the exploitation of pollinators by corolla variants in Phlox, Am. Nat. 106:453–460.Google Scholar
  106. Levin, D. A., and Kerster, H. W., 1974, Gene flow in seed plants, in: Evolutionary Biology, Vol. 7 (T. Dobzhansky, M. Hecht, and W. Steere, eds.), pp. 139–220, Plenum, New York.Google Scholar
  107. Levins, R., 1968, Evolution in Changing Environments, Princeton University Press, Princeton, New Jersey.Google Scholar
  108. Levins, R., and MacArthur, R., 1966, The maintenance of genetic polymorphism in a spatially heterogeneous environment: Variations on a theme by Howard Levene, Am. Nat. 100:585–589.Google Scholar
  109. Lewis, D., 1954, Comparative incompatability in angiosperms and fungi, Adv. Genet. 6:235–285.PubMedGoogle Scholar
  110. Lewontin, R. C., 1968, The effect of differential viability on the population dynamics of t alleles in the house mouse, Evolution 22:262–273.Google Scholar
  111. Loegering, W. Q., and Sears, E. R., 1963, Distorted inheritance of stem-rust resistance of timslein wheat caused by a pollen-killing gene, Can. J. Genet. Cytol. 5:65–72.Google Scholar
  112. Ludwig, W., 1959, Die Selections theorie, in: Die Evolutionen der Organismen (G. Herberer, ed.), pp. 662–712, Fischer, Stuttgart.Google Scholar
  113. Marshall, D. R., 1977, The advantages and hazards of genetic homogeneity, Ann. N. Y. Acad. Sci. 287:1–20.Google Scholar
  114. Marshall, D. R., and Allard, R. W., 1970, Maintenance of isozyme polymorphisms in natural populations of Arena barbata, Genetics 66:393–399.PubMedGoogle Scholar
  115. Mather, K., 1950, The genetical architecture of heterostyly in Primula sinensis, Evolution 4:340–352.Google Scholar
  116. Maynard Smith, J., 1966, Sympatric speciation, Am. Nat. 100:637–650.Google Scholar
  117. McNeilly, T., 1968, Evolution in closely adjacent plant populations. III. Agrostis tenuis on a small copper mine, Heredity 23:205–218.Google Scholar
  118. Mogford, D. J., 1974, Flower colour polymorphism in Circium palustre. 2. Pollination, Heredity 33:257–263.Google Scholar
  119. Mulcahy, D. L., 1964, The reproductive biology of Oxalis priceae, Am. J. Bot. 51:1045–1050.Google Scholar
  120. Mulcahy, D. L., Mulcahy, G. B., and Ottaviano, E., 1975, Sporophytic expression of ga-metophytic competition in Petunia hybrida. in: Gamete Competition in Plants and Animals, (D. L. Mulcahy, ed.), North-Holland, Amsterdam, and American Elsevier, New York.Google Scholar
  121. Muntzing, A., 1968, A case of differential fertilisation in inbred rye, Hereditas 59:298–302.Google Scholar
  122. Murray, J., 1972, Genetic Diversity and Natural Selection. Hafner. New York.Google Scholar
  123. Naylor, A. F., 1962, Mating systems which could increase heterozygosity for a pair of alleles. Am. Nat. 96:51–60.Google Scholar
  124. Nelson, O. E., 1952, Cross sterility in maize. Genetics 37:101–124.PubMedGoogle Scholar
  125. New, J. K., 1958, A population study of Spergula arvensis. Part 1. Two clines and their significance, Ann. Bot. 22:457–477.Google Scholar
  126. Perry, D. A., and Lotan, J. E., 1979, A model of fire selection for serotiny in lodgepole pine, Evolution 33:958–968.Google Scholar
  127. Prout, T., 1953, Some effects of variations in the segregation ratio and of selection on the frequency of alleles, Acta Genet. Statist. Med. 4:148–151.PubMedGoogle Scholar
  128. Prout, T., 1968, Sufficient conditions for multiple niche polymorphism, Am. Nat. 102:493–496.Google Scholar
  129. Putwain, P. D., and Harper, J. L., 1972, Studies in the dynamics of plant populations V. Mechanisms governing the sex ratio in Rumex acetosa and R. acetosella, J. Ecol. 60:113–129.Google Scholar
  130. Rhoades, M. M., 1942, Preferential segregation in maize, Genetics 27:395–407.PubMedGoogle Scholar
  131. Rhodes, I., 1968, Yield of contrasting ryegrass varieties in monoculture and mixed culture, J. Br. Grassl. Soc. 23:156–158.Google Scholar
  132. Rhodes, I., 1969, The yield, canopy structure and light interception of two ryegrass varieties in mixed and monoculture, J. Br. Grassl. Soc. 24:123–127.Google Scholar
  133. Rick, C. M., Fobes, J. F., and Holle, M., 1977, Genetic variation in Lycopersicon pimpi-nellifolium. Evidence of evolutionary change in mating systems, Plant Syst. Ecol. 127:139–170.Google Scholar
  134. Schaal, B. A., 1975, Population structure and local differentiation in Liatris cylindracaea, Am. Nat. 109:511–528.Google Scholar
  135. Schaal, B. A., 1980, Measurement of gene flow in Lupinus texensis, Nature 284:450–451.Google Scholar
  136. Schaal, B. A., and Levin, D. A., 1976, The demographic genetics of Liatris cylindracaea Michx. (Compositae), Am. Nat. 110:191–206.Google Scholar
  137. Schoch-Bodmer, H., 1938, The proportion of long-, mid-, and short-styled plants in natural populations of Lythrum salicaria, J. Genet. 36:39–43.Google Scholar
  138. Schutz, W. M., and Usanis, S. A., 1969, Intergenotypic competition in plant populations II Maintenance of allelic polymorphisms with frequency dependent selection and mixed selfing and random mating, Genetics 61:875–891.PubMedGoogle Scholar
  139. Schutz, W. M., Brim, C. A., and Usanis, S. A., 1968, Intergenotypic competition in plant populations I. Feedback systems with stable equilibria in populations of autogamous homozygous lines, Crop Sci. 8:61–66.Google Scholar
  140. Schwartz, D., 1971, Genetic control of alcohol dehydrogenase—A competition model for regulation of gene action, Genetics 67:411–425.PubMedGoogle Scholar
  141. Scudo, F. M., 1967, Selection on both haplo and diplophase, Genetics 56:693–704.PubMedGoogle Scholar
  142. Seaton, A. J. P., and Antonovics, J., 1967, Population interrelationships I. Evolution in mixtures of Drosophila mutants, Heredity 22:19–33.PubMedGoogle Scholar
  143. Silander, J. A., 1979, Microevolution and clone structure in Spartina patens, Science 203:658–660.PubMedGoogle Scholar
  144. Snaydon, R. W., 1970, Rapid population differentiation in a mosaic environment I. The response of Anthoxanthum odoratum to soils, Evolution 24:257–269.Google Scholar
  145. Snaydon, R. W., and Davies, M. S., 1976, Rapid population differentiation in a mosaic environment IV. Populations of Anthoxanthum odoratum at sharp boundaries, Heredity 37:9–25.Google Scholar
  146. Solbrig, O. T., and Simpson, B. B., 1974, Components of regulation of a population of dandelions in Michigan, J. Ecol. 62:473–486.Google Scholar
  147. Spieth, P. T., 1971, A necessary condition for equilibrium in systems exhibiting self-incompatible mating, Theor. Popul. Biol. 2:404–418.PubMedGoogle Scholar
  148. Strobeck, C., 1974, Sufficient conditions for polymorphism with N. niches and M. mating groups, Am. Nat. 108:152–156.Google Scholar
  149. Strobeck, C., 1975, Selection in a fine grained environment, Am. Nat. 109:419–425.Google Scholar
  150. Sturgeon, K. B., 1979, Monoterpene variation in ponderosa pine xylem resin related to western pine beetle predation, Evolution 33:803–814.Google Scholar
  151. Tucker, C. L., and Harding, J., 1965, Quantitative studies on mating systems II. Estimation of fitness parameters in a population of Phaseolus lunatus, Heredity 20: 393–402.Google Scholar
  152. Turkington, R., and Harper, J. L., 1979, The growth distribution, and neighbour relationships of Trifolium repens in a permanent pasture. IV. Fine-scale biotic differentiation, J. Ecol. 67:245–254.Google Scholar
  153. Vasek, F. C., and Harding, J., 1976, Outcrossing in natural populations. V. Analysis of outcrossing, inbreeding, and selection in Clarkia exilis and Clarkia tembloriensis, Evolution 30:403–411.Google Scholar
  154. Wahl, I., 1970, Prevalence and geographic distribution of resistance to crown rust in Avena sterilis, Phytopathology 60:746–749.Google Scholar
  155. Wallace, B., 1968, Topics in Population Genetics, Norton, New York.Google Scholar
  156. Wallace, B., 1981, Basic Population Genetics, Columbia University Press, New York.Google Scholar
  157. Weir, B. S., and Cockerham, C. C., 1973, Mixed self and random mating at two loci, Genet. Res. Camb. 21:247–262.Google Scholar
  158. Weiler, S. G., 1976, The genetic control of tristyly in Oxalis section Ionoxalis, Heredity 37:387–393.Google Scholar
  159. Werner, P. A., 1978, On the determination of age in Liatris aspersa using cross-sections of corms: Implications for past demographic studies, Am. Nat. 112:1113–1120.Google Scholar
  160. Workman, P. L., 1964, The maintenance of heterozygosity by partial negative assortative mating, Genetics 50:1369–1382.PubMedGoogle Scholar
  161. Workman, P. L., and Jain, S. K., 1966, Zygotic selection under mixed random mating and self-fertilisation: Theory and problems of estimation, Genetics 54:159–171.PubMedGoogle Scholar
  162. Wright, S., 1939, The distribution of self sterility alleles in populations, Genetics 24:538–552.PubMedGoogle Scholar
  163. Wright, S., 1948, On the roles of directed and random changes in gene frequency in the gametes of populations. Evolution 2:279–295.PubMedGoogle Scholar
  164. Wright, S., 1969, Evolution and the Generics of Populations, Vol. 2, The Theory of Gene Frequencies, University of Chicago Press, Chicago, Illinois.Google Scholar
  165. Yu, P., 1972, Some host parasite genetic interaction models, Theor. Popul. Biol. 3:347–352.PubMedGoogle Scholar
  166. Zimmer, D. E., and Rehder, D., 1975, Rust resistance of wild Helianthus species of the north central United States, Phytopathology 66:208–211.Google Scholar
  167. Zimmering, S., Sandler, L., and Nicoletti, B., 1970, Mechanisms of meiotic drive, Annu. Rev. Genet. 4:409–436.PubMedGoogle Scholar

Copyright information

© Plenum Press, New York 1983

Authors and Affiliations

  • R. A. Ennos
    • 1
  1. 1.Department of GeneticsUniversity of Newcastle upon TyneNewcastle upon TyneUK

Personalised recommendations