NATURAL SELECTION, in sexually reproducing plants, should often favour matings between individuals of intermediate genetic similarity. Matings between very similar individuals may lead to inbreeding depression because segregational load is revealed1,2, while matings between very dissimilar individuals may disrupt favourable gene combinations and lead to outbreeding depression3–5. Outbreeding depression in plants has been documented in crosses between species, varieties and isolated populations6–9, and reports of inbreeding depression date back at least a century10 We suggest that outbreeding depression will often occur on a much finer scale than previously recognised, especially in plants subject to restricted pollen and seed dispersal. Such plants are likely to show pronounced microgeographic genetic differentiation resulting from drift in subpopulations isolated by distance or from adaptation to local edaphic and biotic conditions11,12 Under these circumstances, a short outcrossing distance may be optimal not only because of intragenotypic effects, but also because it produces offspring sufficiently similar to the female parent to grow successfully near her, yet sufficiently genotypically diverse to maximise success of the total progeny in the face of coarse-grained temporal environmental variation13–15, frequency-dependent sibling competition16–18 or predation19–20. Here we present evidence that a short outcrossing distance is optimal for Delphinium nelsoni Greene and discuss the relationship between the optimal outcrossing distance for D. nelsoni and actual pollen dispersal by its main pollinators.
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Tax calculation will be finalised during checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Crow, J. F. in Heterosis (ed. Gowen, J. W.) 282–297 (Iowa State College Press, Ames, 1952).
Dobzhansky, T. Genetics of the Evolutionary Process 193–197 (Columbia University Press, New York, 1970).
Darlington, C. D. & Mather, K. The Elements of Genetics 227–229 (Allen and Unwin, London, 1949).
Falconer, D. S. Introduction to Quantitative Genetics 261–263 (Longman, London, 1960).
Prakash, S. & Lewontin, R. C. Proc. Natn. Acad. Sci. U.S.A. 59, 398–405 (1968).
Müller, H. The Fertilisation of Flowers 145–146 (Macmillan, London, 1883).
Kruckeberg, A. R. Evolution 11, 185–211 (1957).
Moll, R. H., Lonnquist, J. H., Velez Fortuno, J. & Johnson, E. C. Genetics 52, 139–144 (1965).
Hughes, K. W. & Vickery, R. K. J. Genet. 61, 235–245 (1974).
Darwin, C. The Effects of Cross and Self Fertilisation in the Vegetable Kingdom (Murray, London, 1876).
Jain, S. K. & Bradshaw, A. D. Heredity 20, 407–441 (1966).
Schaal, B. A. Nature 252, 703 (1974).
Levins, R. Evolution in Changing Environments 10–38 (Princeton University Press, Princeton, 1968).
Selander, R. K. & Kaufman, D. W. Proc. Natn. Acad. Sci. U.S.A. 70, 1875–1877 (1973).
Treisman, M. J. theor. Biol. 60, 421–431 (1976).
Kojima, K. & Yarbrough, K. M. Proc. natn. Acad. Sci. U.S.A. 57, 645–649 (1967).
Seaton, A. P. C. & Antonovics, J. Heredity 22, 19–34 (1967).
Allard, R. W. & Adams, J. Am. Nat. 103, 621–645 (1969).
Clarke, B. in Taxonomy and Geography (ed Nichols, D.) 47–70 (Systematics Association, Oxford, 1962).
Dolinger, P. M., Ehrlich, P. R., Fitch, W. L. & Breedlove, D. E. Oecologia 13, 191–204 (1973).
Waser, N. M. Ecology (in the press).
Sokal, R. R. & Rohlf, F. J. Biometry 621–624 (Freeman, San Francisco, 1969).
Epling, C. & Lewis, H. Evolution 6, 253–267 (1952).
Pyke, G. H. Oecologia 36, 281–293 (1978).
Brink, R. A. Heterosis (ed. Gowen, J. W.) 81–97 (Iowa State College Press, Ames, 1952).
Heslop-Harrsion, J., Heslop-Harrison, Y. & Barber, J. Proc. R. Soc. B188, 287–297 (1975).
Hogenboom, N. G. Proc. R. Soc. B188, 361–375 (1975).
About this article
Cite this article
PRICE, M., WASER, N. Pollen dispersal and optimal outcrossing in Delphinium nelsoni. Nature 277, 294–297 (1979). https://doi.org/10.1038/277294a0
Conservation Genetics (2019)
Pollen dispersal in a population of Passiflora caerulea: spatial components and ecological implications
Plant Ecology (2019)
Testing the effects of genetic crossing distance on embryo survival within a metapopulation of brown trout (Salmo trutta)
Conservation Genetics (2014)
Parental genetic distance and patterns in nonrandom mating and seed yield in predominately selfing Arabidopsis thaliana
Plant Reproduction (2013)