Abstract
Wild rice, Oryza rufipogon, has endangered species conservation status and it is subject to in situ conservation in China. To understand the potential of the seed bank in species conservation and population restoration, this study compared the genetic diversity of O. rufipogon plants with that of its soil seed banks in two marshes. A total of 11 pairs of rice SSR primers were used and 9 were polymorphic. Allele frequencies of the seeds differed significantly from those of surface plants and varied between soil layers. Relatively more alleles and higher genetic diversity (H e) were found in plant populations, relative to seed banks. The numbers of germinable seeds and the level of genetic variation in seed banks decreased with the increasing of soil depth, indicating a rapid seed loss. Genetic differentiation was detected between sites and between plant and seed populations, as well as among seeds of different soil strata. Rapid seed loss, partly dormancy loss, and nonrandom seed mortality are discussed as the possible contributors to the pattern of reduced genetic variation within seed banks, compared to plants. These could also be responsible for the considerable genetic differentiation between populations. The seed population held about 72% of the total genetic variation of O. rufipogon in each marsh, indicating the potential of seed banks for restoring population variabilities if the plant populations were lost.
Similar content being viewed by others
References
Alvarez-Buylia ER, Chaos A, Piv nero D, Garay AA (1996) Demographic genetics of a pioneer tropical tree species: Patch dynamics, seed dispersal, and seed banks. Evolution 50: 1155–1166
Bakker JP, Poschlod P, Strykstra RJ, Bekker RM, Thompson K (1996) Seed banks and seed dispersal: Important topics in restoration ecology. Acta Bot. Neerl. 45: 461–490
Cabin RJ (1996) Genetic comparisons of seed bank and seedling populations of a perennial mustard, Lesquerella fendleri. Evolution 50: 1830–1841
Cabin BJ, Mitchell RJ, Marshall DL (1998) Do surface plant and soil seed bank population differ genetically? A multipopulation study of the desert mustard Lesquerelia fendleri (Brassicaceae). Am. J. Bot. 85: 1098–1109
Chang ER, Jefferies RL, Carleton TJ (2001) Relationship between vegetation and soil seed banks in an arctic coastal marsh. J. Ecol. 89: 367–384
Del Castillo RF (1994) Factors influencing the genetic structure of Phacelia dubia, a species with a seed bank and large fluctuations in population size. Heredity 72: 446–458
Ellner S, Hairston Jr NG (1994) Role of overlapping generations in maintaining genetic variation in a fluctuations environment. Am. Nat. 143: 403–417
Ellstrand NC (1992) Gene flow by pollen: Implications for plant conservation genetics. Oikos 63: 77–86
Ellstrand NC, Elam DR (1993) Population genetic consequences of small population size: Implications for plant conservation. Ann. Rev. Ecol. Syst. 24: 217–242
Gao LZ, Chen W, Jiang WZ, Ge S, Hong DY, Wang XQ (2000) Genetic erosion in the Northern marginal population of the common wild rice Oryza rufipogon Griff. and its conservation, revealed by the change of population genetic structure. Hereditas 133: 47–53
Kalinowski ST (2005) HP-RARE1.0: A computer program for performing rarefaction on measures of allelic richness. Mol. Ecol. Notes 5: 187–189
Kalisz S, McPeek MA (1992) Demography of an age-structured annual: Resampled projection matrices, elasticity analyses, and seed bank effects. Ecology 73: 1082–1093
Kalisz S, McPeek MA (1993) Extinction dynamics, population growth and seed banks – an example using an age-structured annual. Oecologia 95: 314–320
Leck MA, Parker VT, Simpson RL (1989) Ecology of soil seed banks. Academic Press, San Diego, CA
Levin DA (1990) The seed bank as a source of genetic novelty in plants. Am. Nat. 135: 563–572
Li J, Chen JK, Zhou J, He GQ (1999) Dynamics and evaluation of Oryza rufipogon and Ranalisma rostratum population in ex situ conservation of communities. Acta Phytoecol. Sinica 23: 275–282. (In Chinese with English abstract)
Liu GH, Zhou J, Huang DS, Li W (2004) Spatial and temporal dynamics of a restored population of Oryza rufipogon in Huli Marsh, South China. Restor. Ecol. 12: 456–463
Liu GH, Zhou J, Li W, Cheng Y (2005) The seed bank in a subtropical freshwater marsh: Implications for wetland restoration. Aquat. Bot. 81: 1–11
Mahy G, Vekemans X, Jacquemart AL (1999) Patterns of allozymic variation within Calluna vulgaris populations at seed bank and adult stages. Heredity 82: 432–440
Middleton BA (2003) Soil seed banks and the potential restoration of forested wetlands after farming. J. Appl. Ecol. 40: 1025–1034
Nei M (1978) Estimation of average heterozygosity and genetic distance from a small number of individuals. Genetics 89: 583–590
Nunney L (2002) The effective size of annual plant populations: The interaction of a seed bank with fluctuating population size in maintaining genetic variation. Am. Nat. 160: 195–204
Oka HI (1988) Origin of Cultivated Rice. Japanese Scientific Societies Press, Tokyo
Qian J (2003) Conservation Biology Study on the Northern Populations of Oryza rufipogon: Experimental ecology and Spatial Genetic Analysis. PhD thesis, Fudan University, Shanghai China
Rohlf FJ (1993) NTSYS-pc, numerical taxonomy and multivariate analysis, ver. 1.80. Exeter Setauket, New York
Smith LM, Kadlec JA (1983) Seed banks and their role during drawdown of a North American marsh. J. Appl. Ecol. 20: 673–684
Sokal RR, Rohlf FJ (1981) Biometry. WH Freeman, San Francisco, CA
Song ZP, Xu X, Wang B, Chen JK, Lu BR (2003) Genetic diversity in the northernmost Oryza rufipogon populations estimated by SSR markers. Theor. Appl. Genet. 107: 1492–1499
Song ZP, Lu BR, Chen JK (2004b) Pollen flow of cultivated rice measured under experimental conditions. Biodivers. Conserv. 13: 579–590
Song ZP, Lu BR, Wang B, Chen JK (2004a) Fitness estimation through performance comparison of F-1 hybrids with their parental species Oryza rufipogon and O. sativa. Ann. Bot. 93: 311–316
Song ZP, Li B, Chen JK, Lu BR (2005) Genetic diversity and conservation of Common wild rice (Oryza rufipogon) in China. Plant Species Biol. 20(2): 83–92
Templeton AR, Levin DA (1979) Evolutionary consequences of seed pools. Am. Nat. 114: 232–249
Tonsor SJ, Kalisz S, Fisher J, Holtsford TP (1993) A life-history based study of population genetic structure: Seed bank to adults in Plantago lanceolata. Evolution 47: 833–843
van der Valk AG, Davis CB (1978) The role of seed banks in the vegetation dynamics of prairie glacial marshes. Ecology 59: 322–335
Veasey EA, Karasawa MG, Santos PP, Rosa MS, Manani RE, Oliveira GCX (2004) Variation in the loss of seed dormancy during after-ripening of wild and cultivated rice species. Ann. Bot. 94: 875–882
Weir BS, Cockerham CC (1984) Estimating F-statistics for the analysis of population structure. Evolution 38: 1358–1370
Wilson SD, Moore DRJ, Keddy PA (1993) Relationships of marsh seed banks to vegetation patterns along environmental gradients. Freshw. Biol. 29: 361–370
Xie ZW, Ge S, Hong DY (1999) Preparation of DNA from silica gel a dried mini-amount of leaves of Oryza rufipogon for RAPD study and total DNA bank construction. Acta Bot. Sinica 41: 807–812
Yeh FC, Yang RC, Boyle T (1999) POPGENE, Microsoft window-based freeware for population genetic analysis. http://www.microsoft.com /softlib/ MSLFILES/HPGL.EXE
Zhou J (1995) Studies on Conservation Biology of Three Northern Populations of Common Wild Rice (Oryza rufipogon) (in Chinese). PhD thesis, Wuhan University, Wuhan, China
Acknowledgments
We thank Dr. Anthony J. Davy for correcting the English and providing valuable comments, You-ping Liu for field assistance, Shu-fei Chen for glasshouse work and Dr. Hong-wen Huang for SSR assays. Financial support was provided by the National Natural Science Foundation of China (Grant No. 30300019), the Innovation Key project of CAS (KSCX2-1-10), and the State Key Basic Research and Development Plan of China (2002CB412300).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Liu, Gh., Luo, Lm., Wang, B. et al. Comparison of genetic variation in populations of wild rice, Oryza rufipogon, plants and their soil seed banks. Conserv Genet 7, 909–917 (2006). https://doi.org/10.1007/s10592-006-9132-y
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10592-006-9132-y