Potential Inbreeding in a Small Population of a Mass Flowering Species, Xanthorrhoea johnsonii (Xanthorrhoeaceae): Is Your Mother My Father?


Xanthorrhoea johnsonii is a long lived slow growing perennial understorey species, that produces a large quantity of passively dispersed seed every 3 - 5 years. Reproductive maturity is not reached until 20 - 30 years of age. The temporal asynchrony of the flowering event in this population was analogous to geographic isolation through fragmentation. A small population of plants flowering in isolation provided the opportunity to examine outcrossing rates, genetic diversity and the paternity of progeny at a small spatial scale (0.2 ha). The geographic location and physical characteristics of the adult plants were recorded, and both adults and their seed were sampled for genetic analysis. Four microsatellite loci were screened for genetic diversity and spatial structure analysis. A population outcrossing rate was estimated, as well as the number of paternal parents required to resolve the progeny multilocus genotypes. High genetic diversity was found in both adults and progeny with an estimated 97% outcrossing rate. All maternal lines required several paternal contributors, with no evidence of dominant paternal genotypes. Pollen transfer occurred between both geographically close and distant plants.

Share and Cite:

R. King and J. M. Zalucki, "Potential Inbreeding in a Small Population of a Mass Flowering Species, Xanthorrhoea johnsonii (Xanthorrhoeaceae): Is Your Mother My Father?," American Journal of Plant Sciences, Vol. 3 No. 3, 2012, pp. 303-312. doi: 10.4236/ajps.2012.33036.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] I. Bartish Peterson and J. Peterson, “Effects of Population Size on Genetic Diversity, Fitness and Pollinator Community Composition in Fragmented Populations of Anthericum liliago L,” Plant Ecology, Vol. 198, No. 1, 2008, pp. 101-110. doi:10.1007/s11258-007-9388-4
[2] N. J. Ouborg, P. Vergeer and C. Mix, “The Rough Edges of the Conservation Genetics Paradigm for Plants,” Journal of Ecology, Vol. 94, No. 6, 2006, pp. 1233-1248. doi:10.1111/j.1365-2745.2006.01167.x
[3] G. Caughley, “Directions in Conservation Biology,” Journal of Animal Ecology, Vol. 63, No. 2, 1994, pp. 215-244. doi:10.2307/5542
[4] P. Crnokrak and D. A. Roff, “Inbreeding Depression in the Wild,” Heredity, Vol. 83, No. 3, 1999, pp. 260-270. doi:10.1038/sj.hdy.6885530
[5] N. C. Ellstrand and D. R. Elam, “Population Genetic Consequences of Small Population-Size—Implications for Plant Conservation,” Annual Review of Ecology and Systematics, Vol. 24, No. 1, 1993, pp. 217-242. doi:10.1146/annurev.es.24.110193.001245
[6] D. A. Falk and K. E. Holsinger (Eds.), “Genetics and Conservation of Rare Plants,” Oxford University Press, New York, 1991.
[7] R. Zhao, H. Xia and B. R. Lu, “Fine-Scale Genetic Structure Enhances Biparental Inbreeding by Promoting Mating Events between More Related Individuals in Wild Soybean (Glycine Soja; Fabaceae) Populations,” American Journal of Botany, Vol. 96, No. 6, 2009, pp. 1138-1147. doi:10.3732/ajb.0800173
[8] S. C. H. Barrett and J. R. Kohn, “Genetic and Evolutionary Consequences of Small Population Size in Plants: Implications for Conservation,” In: D. A. Falk and K. E. Holsinger, Eds., Genetics and Conservation of Rare Plants Oxford University Press, New York, 1991, pp. 3-30.
[9] O. Honnay and H. Jacquemyn, “Susceptibility of Common and Rare Plant Species to the Genetic Concequences of Habitat Fragmentation,” Conservation Biology, Vol. 21, No. 3, 2006, pp. 823-831. doi:10.1111/j.1523-1739.2006.00646.x
[10] A. Young, T. Boyle and T. Brown, “The Population Genetic Consequences of Habitat Fragmentation for Plants,” Trends in Ecology and Evolution, Vol. 11, No. 10, 1996, pp. 413-418. doi:10.1016/0169-5347(96)10045-8
[11] Q. F. Geng, C. L. Lian, S. Goto, J. M. Tao, M. Kimura, M. D. S. Islam and T. Hogetsu, “Mating System, Pollen and Propagule Dispersal, and Spatial Genetic Structure in a High-Density Population of the Mangrove Tree Kandelia Candel,” Molecular Ecology, Vol. 17, No. 21, 2008, pp. 4724-4739. doi:10.1111/j.1365-294X.2008.03948.x
[12] Y. Isagi, D. Saito, H. Kawaguchi, R. Tateno and S. Watanabe, “Effective Pollen Dispersal Is Enhanced by the Genetic Structure of an Aesculus Turbinata Population,” Journal of Ecology, Vol. 95, No. 5, 2007, pp. 983-990. doi:10.1111/j.1365-2745.2007.01272.x
[13] T. Kenta, Y. Isagi, M. Nakagawa, M. Yamashita and T. Nakashizuka, “Variation in Pollen Dispersal between Years with Different Pollination Conditions in a Tropical Emergent Tree,” Molecular Ecology, Vol. 13, No. 11, 2004, pp. 3575-3584. doi:10.1111/j.1365-294X.2004.02345.x
[14] C. F. Williams, “Effects of Floral Display Size and Biparental Inbreeding on Outcrossing Rates in Delphinium barbeyi (Ranunculaceae),” American Journal of Botany, Vol. 94, No. 10, 2007, pp. 1696-1705. doi:10.3732/ajb.94.10.1696
[15] M. B. Routley and B. C. Husband, “The Effect of Protandry on Siring Success in Chamerion angustifolium (Onagraceae) with Different Inflorescence Sizes,” Evolution, Vol. 57, No. 2, 2003, pp. 240-248.
[16] G. H. Pyke, “Optimal Foraging: Movement Patterns of Bumblebees between Infloresences,” Theoretical Population Biology, Vol. 13, 1978, pp. 72-98. doi:10.1016/0040-5809(78)90036-9
[17] H. S. Ishii, Y. Hirabayashi and G. Kudo, “Combined Effects of Inflorescence Architecture, Display Size, Plant Density and Empty Flowers on Bumble Bee Behaviour: Experimental Study with Artificial Inflorescences,” Oecologia, Vol. 156, No. 2, 2008, pp. 341-350. doi:10.1007/s00442-008-0991-4
[18] J. D. Karron, K. G. Holmquist, R. J. Flanagan and R. J. Mitchell, “Pollinator Visitation Patterns Strongly Influence among-Flower Variation in Selfing Rate,” Annals of Botany, Vol. 103, No. 9, 2009, pp. 1379-1383. doi:10.1093/aob/mcp030
[19] M. O. Johnston, E. Porcher, P. A. Cheptou, C. G. Eckert, E. Elle, M. A. Geber, S. Kalisz, J. K. Kelly, D. A. Moeller, M. Vallejo-Marín and A. A. Winn, “Correlations among Fertility Components Can Maintain Mixed Mating in Plants,” The American Naturalist, Vol. 173, No. 1, 2009, pp. 1-11. doi:10.1086/593705
[20] J. P. Gonzalez-Varo, R. G. Albaladejo and A. Aparicio, “Mating Patterns and Spatial Distribution of Conspecific Neighbours in the Mediterranean Shrub Myrtus communis (Myrtaceae),” Plant Ecology, Vol. 203, No. 2, 2009, pp. 207-215. doi:10.1007/s11258-008-9534-7
[21] J. C. Avise, “Molecular Markers, Natural History and Evolution,” Chapman & Hall, New York, 1994, p. 511. doi:10.1007/978-1-4615-2381-9
[22] S. G. Michalski and W. Durka, “High Selfing and High Inbreeding Depression in Peripheral Populations of Juncus Atratus,” Molecular Ecology, Vol. 16, No. 22, 2007, pp. 4715-4727. doi:10.1111/j.1365-294X.2007.03547.x
[23] O. J. Hardy, S. C. Gonzalez-Martinez, B. Colas, H. Freville, A. Mignot and I. Olivieri, “Fine-Scale Genetic Structure and Gene Dispersal in Centaurea corymbosa (Asteraceae). II. Correlated Paternity within and among Sibships,” Genetics, Vol. 168, No. 3, 2004, pp. 1601-1614. doi:10.1534/genetics.104.027714
[24] M. Gaudeul and I. Till-Bottraud, “Low Selfing in a Mass-Flowering, Endangered Perennial, Eryngium alpinum L. (Apiaceae),” American Journal of Botany, Vol. 90, No. 5, 2003, pp. 716-723. doi:10.3732/ajb.90.5.716
[25] J. M. Zalucki, “A Study of the Repoductive Biology of Xanthorrhoea johnsonii (Xanthorrhoaceae) in Toohey Forest,” Ph.D. Thesis, Griffith University, Nathan, 1998.
[26] B. B. Lamont, R. Wittkuhn and D. Korczynskyj, “Turner Review No. 8 Ecology and Ecophysiology of Grasstrees,” Australian Journal of Botany, Vol. 52, No. 5, 2004, pp. 561-582. doi:10.1071/BT03127
[27] A.T. Lee, “Notes on Xanthorrhoea in Eastern Australia,” Contributions from the N.S.W. National Herbarium, Vol. 4, 1966, pp. 35-54.
[28] D. J. Bedford, A. T. Lee, T. D. Macfarlane, R. J. F. Henderson and A. S. George, “Xanthorrhoeaceae,” In: A. E. Orchard, Ed., Flora of Australiam, Vol. 46, Australian Government Publishing Service, Canberra, 1986, pp. 88-171.
[29] I.A. Staff, “The Fruits and Seed Productivity in Xanthorrhoea Species,” Proceedings of the Linnean Society of N.S.W., Vol. 100, 1975, pp. 95-102.
[30] C. R. Loomis, G. G. Shipley and D. M. Small, “Phase-Behavior of Hydrated Cholesterol,” Journal of Lipid Research, Vol. 20, No. 4, 1979, pp. 525-535.
[31] S. D. Song, R. A. I. Drew and J. M. Hughes, “Multiple Paternity in a Natural Population of a Wild Tobacco Fly, Bactrocera cacuminata (Diptera: Tephritidae), Assessed by Microsatellite DNA Markers,” Molecular Ecology, Vol. 16, No. 11, 2007, pp. 2353-2361. doi:10.1111/j.1365-294X.2007.03277.x
[32] C. van Oosterhout, W. F. Hutchinson, D. P. M. Wills and P. F. Shipley, “Micro-Checker User Guide,” The University of Hull, Hull, 2003.
[33] R. Chakraborty, M. Deandrade, S. P. Daiger and B. Budowle, “Apparent Heterozygote Deficiencies Observed in DNA Typing Data and Their Implications in Forensic Applications,” Annals of Human Genetics, Vol. 56, 1992, pp. 45-57. doi:10.1111/j.1469-1809.1992.tb01128.x
[34] J. F. Y. Brookfield, “A Simple New Method for Estimating Null Allele Frequency from Heterozygote Deficiency,” Molecular Ecology, Vol. 5, No. 3, 1996, pp. 453-455.
[35] M. Raymond and F. Rousset, “Genepop (Version 1.2): Population Genetics Software for Exact Tests and Ecumenicism,” Journal of Heredity, Vol. 86, No. 3, 1995, pp. 248-249.
[36] B. S. Weir and C. C. Cockerham, “Estimating F-Statistics for the Analysis of Population Structure,” Evolution, Vol. 38, No. 6, 1984, pp. 1358-1370. doi:10.2307/2408641
[37] D. C. Queller and K. F. Goodnight, “Estimating Relatedness Using Genetic-Markers,” Evolution, Vol. 43, No. 2, 1989, pp. 258-275. doi:10.2307/2409206
[38] P. E. Smouse and R. Peakall, “Spatial Autocorrelation Analysis of Individual Multiallele and Multilocus Genetic Structure,” Heredity, Vol. 82, No. 5, 1999, pp. 561-573. doi:10.1038/sj.hdy.6885180
[39] R. Peakall and P. E. Smouse, “Genalex 6: Genetic Analysis in Excel. Population Genetic Software for Teaching and Research,” Molecular Ecology Notes, Vol. 6, No. 1, 2006, pp. 288-295. doi:10.1111/j.1471-8286.2005.01155.x
[40] R. Peakall, D. Ebert, L. J. Scott, P. F. Meagher and C. A. Offord, “Comparative Genetic Study Confirms Exceptionally Low Genetic Variation in the Ancient and Endangered Relictual Conifer, Wollemia nobilis (Araucariaceae),” Molecular Ecology, Vol. 12, No. 9, 2003, pp. 2331-2343. doi:10.1046/j.1365-294X.2003.01926.x
[41] T. C. Marshall, J. Slate, L. E. B. Kruuk and J. M. Pemberton, “Statistical Confidence for Likelihood-Based Paternity Inference in Natural Populations,” Molecular Ecology, Vol. 7, No. 5, 1998, pp. 639-655. doi:10.1046/j.1365-294x.1998.00374.x
[42] A. G. Jones, “Gerud 2.0: A Computer Program for the Reconstruction of Parental Genotypes from Half-Sib Progeny Arrays with Known or Unknown Parents,” Molecular Ecology Notes, Vol. 5, No. 3, 2005, pp. 708-711. doi:10.1111/j.1471-8286.2005.01029.x
[43] A.Bulow-Olsen, J. Just and M. J. Liddle, “Growth and Flowering History of Xanthorrhoea johnsonii Lee (Liliaceae) in Toohey Forest Queensland,” Botanical Journal of the Linnean Society, Vol. 84, No. 3, 1982, pp. 195-207. doi:10.1111/j.1095-8339.1982.tb00534.x
[44] J. L. Hamrick, D. A. Murawski and J. D. Nason, “The Influence of Seed Dispersal Mechanisms on the Genetic-Structure of Tropical Tree Populations,” Vegetatio, Vol. 108, No. 1, 1993, pp. 281-297.
[45] J. L. Hamrick and J. D. Nason, “Gene Flow in Forest Trees,” In: A. Young, D. Boshier and T. Boyle, Eds., Forest Conservation and Genetics: Principles and Practice, CSIRO Pub., Collingwood, 2000, pp. 81-90.

Copyright © 2024 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.