Abstract
We examined the quantitative genetics of 20 floral traits in Mimulus guttatus including flowering time, autofertility, flower size, the spatial arrangement of flower parts, pollen and ovule production and seed number and size. A six by six diallel crossing design including selfs was performed in the glasshouse between plants derived from one population of M. guttatus from California. All characters with the exception of pollen number showed significant amounts of additive genetic variance indicating a potential to respond to selection. A principal components analysis revealed that some variation in many characters could be explained by general flower size. However, most characters still displayed heritable variation after the flower size effect was removed by analysis of covariance. Families snowed considerable variation in the ability to self in glasshouse conditions. Only a weak relationship between autofertility and herkogamy was detected, suggesting that an unidentified mechanism was responsible for differences in selfing ability. Pollen quality and ovule production were also strongly heritable, suggesting the potential for gender specialization of plants but no trade-off between male and female function could be detected. Inbreeding depression was evident in flower size and pollen and ovule production. It is postulated that the heritable variation observed is maintained in this population through disruptive selection on autofertility in response to seasonal variation in the onset of spring drought and pollinator availability.
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Arthur, A E, Gale, J S, and Lawrence, M J. 1973. Variation in wild populations of Papaver dubium. VII. Germination time. Heredity, 30, 189–197.
Baker, H G. 1983. An outline of the history of anthecology, or pollination biology. In: Real, L. (ed.) Pollination Biology, pp. 7–28. Academic Press, Orlando.
Bière, A. 1991a. Parental effects in Lychnis floscuculi. I. Seed size, germination and seedling performance in a controlled environment. J Evol Biol, 4, 447–465.
Biere, A. 1991b. Parental effects in Lychnis floscuculi. II. Selection on time of emergence and seedling performance in the field. J Evol Biol, 4, 467–486.
Boag, P T. 1983. The heritability of external morphology in Darwin's ground finches (Geospiza) on Isla Daphne Major, Galapagos. Evolution, 37, 877–894.
Campbell, D R. 1991. Effects of floral traits on sequential components of fitness in Ipomopsis aggregata. Am Nat, 137, 713–737.
Campbell, D R, Waser, N M, Price, M V, Lynch, E A, and Mitchell, R J. 1991. Components of phenotypic selection-pollen export and flower corolla width in Ipomopsis aggregata. Evolution, 45, 1458–1467.
Charlesworth, D, and Charlesworth, B. 1981. Allocations of resources to male and female functions in hermaphrodites. Biol J Linn Soc, 15, 57–74.
Charlesworth, D, and Morgan, M T. 1991. Allocation of resources to sex functions in flowering plants. Phil Trans R Soc Lond B, 332, 91–102.
Charnov, E. 1982. The Theory of Sex Allocation. Princeton University Press, Princeton.
Darwin, C. 1862. On the Various Contrivances by which Orchids Are Fertilised by Insects. Murray, London.
Dickinson, A G, and Jinks, J L. 1956. A generalised analysis of diallel crosses. Genetics, 41, 65–78.
Dole, J A. 1990. Role of corolla abscission in delayed self-pollination of Mimulus guttatus (Scrophulariaceae). Am J Bot, 77, 1505–1507.
Dole, J A. 1992. Reproductive assurance mechanisms in three taxa of the Mimulus guttatus complex (Scrophulariaceae). Am J Bot, 79, 650–659.
Dorn, L A, and Mitchell-Olds, T. 1991. Genetics of Brassica campestris. I. Genetic constraints on evolution of life-history characters. Evolution, 45, 371–379.
Dudash, M R, and Ritland, K. 1991. Multiple paternity and self-fertilization in relation to floral age in Mimulus guttatus (Scrophulariaceae). Am J Bot, 78, 1746–1753.
Falconer, D S. 1989. Introduction to Quantitative Genetics, 3rd edn. Longman, London.
Fisher, R A. 1930. The Genetical Theory of Natural Selection. Clarendon Press, Oxford.
Galen, C. 1989. Measuring pollinator-mediated selection on morphometric floral traits: bumblebees and the Alpine Sky Pilot, Polemonium viscosum. Evolution, 43, 882–890.
Haig, D, and Westoby, M. 1988. Inclusive fitness, seed resources and maternal care. In: Lovett Doust, J. and Lovett Doust, L. (eds) Plant Reproductive Ecology, pp. 60–79. Oxford University Press, New York.
Haldane, J B S, and Jayakar, S D. 1963. Polymorphism due to selection of varying direction. J Genet, 58, 237–242.
Harper, J L, Lovell, P H, and Moore, K G. 1970. The shapes and sizes of seeds. Ann Rev Ecol Syst, 1, 327–356.
Kiang, Y T, and Hamrick, J L. 1978. Reproductive isolation in the Mimulus guttatus-M. nasutus complex. Am Midi Nat, 100, 269–276.
Lande, R. 1976. The maintenance of genetic variability by mutation in a polygenic character with linked loci. Genet Res, 26, 221–235.
Lloyd, D G. 1987. Allocations to pollen, seeds and pollination mechanisms in self-fertilizing plants. Funct Ecol, 1, 83–89.
Macnair, M R, and Cumbes, Q J. 1989. The genetic architecture of interspecific variation in Mimulus. Genetics, 122, 211–222.
Martin, B E. 1988. Floral fragrance and pollination in the yellow monkey flower Mimulus guttatus Fischer ex D.C. (Scrophulariacae). Ph.D. Thesis, University of Exeter.
Mather, K, and Jinks, J L. 1982. Biometrical Genetics, 3rd edn. Chapman and Hall, London.
Mazer, S J. 1987. The quantitative genetics of life history and fitness components in Raphanus rhaphanistrum L. (Brassicaceae): ecological and evolutionary consequences of seed-weight variation. Am Nat, 130, 891–914.
Mitchell-Olds, T. 1986. Quantitative genetics of survival and growth in Impatiens capensis. Evolution, 40, 107–116.
Mitchell-Olds, T, and Rutledge, J J. 1986. Quantitative genetics in natural plant populations: a review of the theory. Am Nat, 127, 379–402.
Mossop, R, Macnair, M R, and Robertson, A W. 1994. Within population variation in sexual resource allocation in Mimulus guttatus. Fund Ecol, in press.
Rick, C M, Forbes, J F, and Holle, M. 1977. Genetic variation in Lycopersicon pimpinellifolium: evidence of evolutionary change in mating systems. Plant Syst Evol, 127, 139–170.
Ritland, C, and Ritland, K. 1989. Variation of sex allocation among eight taxa of the Mimulus guttatus species complex (Scrophulariaceae). Am J Bot, 76, 1731–1739.
Ritland, K. 1989. Correlated matings in the partial selfer Mimulus guttatus. Evolution, 43, 848–859.
Ritland, K, and Ganders, F R. 1987a. Covariation of selfing rates with parental gene fixation indexes within populations of Mimulus guttatus. Evolution, 41, 760–771.
Ritland, K, and Ganders, F R. 1987b. Crossability of Mimulus guttatus in relation to components of gene fixation. Evolution, 41, 772–786.
Robertson, A W, and Lloyd, D G. 1991. Herkogamy, dichogamy and self-pollination in six species of Myosotis (Boraginaceae). Evol Trends Plants, 5, 53–63.
Rose, M R. 1982. Antagonistic pleiotropy, dominance and genetic variation. Heredity, 48, 63–78.
Ross, M D, and Gregorius, H R. 1983. Outcrossing and sex function in hermaphrodites: a resource-allocation model. Am Nat, 121, 204–222.
Schwaegerle, K E, and Levin, D A. 1991. Quantitative genetics of fitness traits in a wild population of Phlox. Evolution, 45, 169–177.
Searcy, K B, and Macnair, M R. 1990. Differential seed production in Mimulus guttatus in response to increasing concentrations of copper in the pistil by pollen from copper tolerant and sensitive sources. Evolution, 44, 1424–1435.
Service, P M, and Rose, M R. 1985. Genetic covariance among life-history components: the effect of novel environments. Evolution, 39, 943–945.
Stanton, M, Young, H J, Ellstrand, N C, and Clegg, J M. 1991. Consequences of floral variation for male and female reproduction in experimental populations of wild radish, Raphanus sativus L. Evolution, 45, 268–280.
Vasek, F C. 1965. Outcrossing in natural populations. II. Clarkia unguiculata. Evolution, 19, 152–156.
Wearden, S. 1965. Alternative analysis of the diallel cross. Heredity, 20, 669–680.
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Robertson, A., Diaz, A. & Macnair, M. The quantitative genetics of floral characters in Mimulus guttatus. Heredity 72, 300–311 (1994). https://doi.org/10.1038/hdy.1994.40
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DOI: https://doi.org/10.1038/hdy.1994.40
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