Genetic characterization of the entire range of Cycas panzhihuaensis (Cycadaceae)

doi:10.1016/j.pld.2019.10.001

Abstract

Abstract: Cycas panzhihuaensis L. Zhou & S. Y. Yang (Cycadaceae) is an endangered gymnosperm species endemic to the dry-hot valley of the Jinsha River basin in southwest China. Although the wild C. panzhihuaensis population from Panzhihua Cycad Natural Reserve is well protected and its genetic diversity has been well assessed, the genetic characteristics of populations outside the nature reserve, which face larger risks of extinction, remain unknown. Furthermore, the population genetics and historical dynamics of this endemic and endangered species have not been examined across its entire range. In this study, to analyze the genetic diversity, phylogeographical structure and demographic history of C. panzhihuaensis from all its seven known locations, we sequenced and compared molecular data from chloroplastic DNA (psbA-trnH, psbM-trnD, and trnS-trnG), single-copy nuclear genes (PHYP, AC5, HSP70, and AAT) from 61 individuals, as well as 11 nuclear microsatellite loci (SSR) from 102 individuals. We found relatively high genetic diversity within populations and high genetic differentiation among populations of C. panzhihuaensis, which is consistent with the patterns of other Asian inland cycads. Although no significant phylogeographical structure was detected, we found that small and unprotected populations possess higher genetic diversity and more unique haplotypes, which revises our understanding of diversity within this species and deserves due attention. Analysis of demographic dynamics suggest that human activity might be the key threat to C. panzhihuaensis. Based on the genetic characterization of C. panzhihuaensis, we propose several practical guidelines for the conservation of this species, especially for the populations with small sizes.

Key words: Cycas panzhihuaensis, Conservation, Genetic diversity, Phylogeography, Chloroplast and nuclear DNA, Microsatellite

Siyue Xiao, Yunheng Ji, Jian Liu, Xun Gong. Genetic characterization of the entire range of Cycas panzhihuaensis (Cycadaceae)[J]. Plant Diversity, 2020, 42(01): 7-18.

References

Araújo, M.B., Williams, P.H., 2001. The bias of complementarity hotspots toward marginal populations. Conserv. Biol. 15, 1710-1720.
Barker, F.K., Lutzoni, F.M., 2002. The utility of the incongruence length difference test. Syst. Biol. 51, 625-637.
Chiang, Y.C., Hung, K.H., Moore, S.J., Ge, X.J., Huang, S., Hsu, T.W., Schaal, B.A., Chiang, T., 2009. Paraphyly of organelle DNAs in Cycas Sect. Asiorientales due to ancient ancestral polymorphisms. BMC Evol. Biol. 9, 161.
Condamine, F.L., Nagalingum, N.S., Marshall, C.R., Morlon, H., 2015. Origin and diversification of living cycads:a cautionary tale on the impact of the branching process prior in Bayesian molecular dating. BMC Evol. Biol. 15, 65.
De La Torre, A.R., Li, Z., Van de Peer, Y., Ingvarsson, P.K., 2017. Contrasting rates of molecular evolution and patterns of selection among gymnosperms and flowering plants. Mol. Biol. Evol. 34, 1363-1377.
Doyle, J., 1991. DNA protocols for plants. In:Hewitt, G.M., Johnston, A.W.B., Young, J.P.W. (Eds.), Molecular Techniques in Taxonomy. Springer, Berlin, Heidelberg, pp. 283-293.
Drummond, A.J., Suchard, M.A., Xie, D., Rambaut, A., 2012. Bayesian phylogenetics with BEAUti and the BEAST 1.7. Mol. Biol. Evol. 29, 1969-1973.
Earl, D.A., vonHoldt, B.M., 2012. STRUCTURE HARVESTER:a website and program for visualizing STRUCTURE output and implementing the Evanno method. Conserv. Genet. Resour. 4, 359-361.
Etterson, J.R., 2004. Evolutionary potential of Chamaecrista fasciculata in relation to climate change. II. Genetic architecture of three populations reciprocally planted along an environmental gradient in the great plains. Evolution 58, 1459-1471.
Feng, X.Y., Zheng, Y., Gong, X., 2016. Middle-Upper Pleistocene climate changes shaped the divergence and demography of Cycas guizhouensis (Cycadaceae):evidence from DNA sequences and microsatellite markers. Sci. Rep. 6, 27368.
Feng, X., Liu, J., Chiang, Y.C., Xun, G., 2017. Investigating the genetic diversity, population differentiation and population dynamics of Cycas segmentifida(Cycadaceae) endemic to southwest China by multiple molecular markers.Front. Plant Sci. 8, 839.
Forster, Michael, 2015. Network 5.0.0.0 User Guide. Network, pp. 1-55. http://fluxus-engineering.com/Network5000_user_guide.pdf Downloaded on.(Accessed 10 November 2017).
Frankham, R., Bradshaw, C.J.A., Brook, B.W., 2014. Genetics in conservation management:revised recommendations for the 50/500 rules, Red List criteria and population viability analyses. Biol. Conserv. 170, 56-63.
Fredrik, R., Maxim, T., Paul, V.D.M., Ayres, D.L., Aaron, D., Sebastian, H., Bret, L., Liang, L., Suchard, M.A., Huelsenbeck, J.P., 2012. MrBayes 3.2:efficient bayesian phylogenetic inference and model choice across a large model space. Syst. Biol. 61, 539-542.
Gong, Y.Q., Gong, X., 2016. Pollen-mediated gene flow promotes low nuclear genetic differentiation among populations of Cycas debaoensis (Cycadaceae). Tree Genet. Genomes 12, 93.
Gong, X., Luan, S.S., Hung, K.H., Hwang, C.C., Lin, C.J., Chiang, Y.C., Chiang, T.Y., 2011. Population structure of Nouelia insignis (Asteraceae), an endangered species in southwestern China, based on chloroplast DNA sequences:recent demographic shrinking. J. Plant Res. 124, 221-230.
Griffith, M.P., Calonje, M., Meerow, A.W., Tut, F., Kramer, A.T., Hird, A., Magellan, T.M., Husby, C.E., 2015. Can a botanic garden Cycad collection capture the genetic diversity in a wild population? Int. J. Plant Sci. 176, 1-10.
Griffith, M.P., Calonje, M., Meerow, A.W., Francisco-Ortega, J., Knowles, L., Aguilar, R., Tut, F., Sanchez, V., Meyer, A., Noblick, L.R., Magellan, T.M., 2017. Will the same ex situ protocols give similar results for closely related species? Biodivers. Conserv. 26, 2951-2966.
Hall, T.A., 1999. BioEdit:A User-Friendly Biological Sequence Alignment Editor and Analysis Program for Windows 95/98/NT. Nucleic Acids Symposium Series 41, 95-98.
Hall, J.A., Walter, G.H., 2011. Does pollen aerodynamics correlate with pollination vector? Pollen settling velocity as a test for wind versus insect pollination among cycads (Gymnospermae:Cycadaceae:Zamiaceae). Biol. J. Linn. Soc. 104, 75-92.
Hamilton, M.B., 1999. Four primer pairs for the amplification of chloroplast intergenic regions with intraspecific variation. Mol. Ecol. 8, 521-523.
Han, J., Wang, M.C., Qiu, Q., Guo, R.Y., 2016. Characterization of the complete chloroplast genome of Cycas panzhihuaensis. Conserv. Genet. Resour. 9, 21-23.
Hao, Y.Q., 2011. Florogeographical analysis of spermatophytes in Cycas panzhihuaensis assemblage. J. Sichuan Forest Sci. Technol. 32, 29-33 (In Chinese with English abstract).
He, Y.H., Li, C.L., 1999. The ecological geographic distribution, spatial pattern and collecting history of Cycas panzhihuaensis populations. Acta Phytoecol. Sin. 23, 23-30 (In Chinese with English abstract).
Hill, K., Chen, C., Loc, P., 2003. Chapter 5:regional overview:Asia. In:Donaldson, J.(Ed.), Cycads:Status Survey and Conservation Action Plan. IUCN/SSC Cycad Specialist Group., IUCN, Gland, Switzerland and Cambridge, pp. 25-30.
Huang, S., Chiang, Y.C., Schaal, B.A., Chou, C.H., Chiang, T.Y., 2001. Organelle DNA phylogeography of Cycas taitungensis, a relict species in Taiwan. Mol. Ecol. 10, 2669-2681.
IUCN, 2017. The IUCN Red List of Threatened Species. Version 2017-3. http://www.iucnredlist.org. (Accessed 5 December 2017).
James, H.E., Forster, P.I., Lamont, R.W., Shapcott, A., 2018. Conservation genetics and demographic analysis of the endangered cycad species Cycas megacarpa and the impacts of past habitat fragmentation. Aust. J. Bot. 66, 173-189.
Jia, J., Wu, H., Wang, J.F., Xun, G., 2014. Genetic diversity and structure of Munronia delavayi Franch. (Meliaceae), an endemic species in the dry-hot valley of Jinsha River, south-western China. Genet. Resour. Crop Evol. 61, 1381-1395.
Jin, Z., 1999. The floristic study on seed plants in the dry-hot valleys in Yunnan and Sichuan. Guihaia 19, 1-14 (In Chinese with English abstract).
Jump, A.S., Penuelas, J., 2005. Running to stand still:adaptation and the response of plants to rapid climate change. Ecol. Lett. 8, 1010-1020.
Kalyaanamoorthy, S., Minh, B.Q., Wong, T.K.F., von Haeseler, A., Jermiin, L.S., 2017. ModelFinder:fast model selection for accurate phylogenetic estimates. Nat. Methods 14, 587.
Kark, S., Alkon, P.U., Safriel, U., Randi, E., 1999. Conservation priorities for chukar partridge in Israel based on genetic diversity across an ecological gradient. Conserv. Biol. 13, 542-552.
Kaulfuss, F., Reisch, C., 2017. Reintroduction of the endangered and endemic plant species Cochlearia bavarica-Implications from conservation genetics. Ecol. Evol. 7, 11100-11112.
Kovach, W., 1998. MVSP-A Multivariate Statistical Package for Windows, Ver. 3.1. Kovach Comput Serv, Wales, UK 137. https://mvsp-a-multivariate-statisticalpackage.apponic.com/Downloaded on. (Accessed 25 March 2017).
Li, L., Wang, Z.F., Jian, S.G., Zhu, P., Zhang, M., Ye, W.H., Ren, H., 2009. Isolation and characterization of microsatellite loci in endangered Cycas changjiangensis(Cycadaceae). Conserv. Genet. 10, 793-795.
Li, Y.Y., Tsang, E.P.K., Cui, M.Y., Chen, X.Y., 2012. Too early to call it success:an evaluation of the natural regeneration of the endangered Metasequoia glyptostroboides. Biol. Conserv. 150, 1-4.
Liu, G.F., Deng, T.X., Zhou, L., Yang, S.Y., 1990. Karyotype analysis of Cycas panzhihuaensis L. Zhou & S.Y.Yang. Chin. J. Plant Ecol. 14, 23-30 (In Chinese with English abstract).
Liu, J., Zhou, W., Gong, X., 2015. Species delimitation, genetic diversity and population historical dynamics of Cycas diannanensis (Cycadaceae) occurring sympatrically in the Red River region of China. Front. Plant Sci. 6, 696.
Liu, H., Lin, W.Y., Li, X.Y., 2016. Chinese nature reserve continues experimental use of fire to benefit the threatened Cycas panzhihuaensis. Oryx 50, 582.
Liu, J., Zhang, S.Z., Nagalingum, N.S., Chiang, Y.C., Lindstrom, A.J., Gong, X., 2018. Phylogeny of the gymnosperm genus Cycas L. (Cycadaceae) as inferred from plastid and nuclear loci based on a large-scale sampling:evolutionary relationships and taxonomical implications. Mol. Phylogenetics Evol. 127, 87-97.
Mankga, L.T., Yessoufou, K., 2017. Factors driving the global decline of cycad diversity. AoB Plants 9, plx022.
Münzbergová, Z., Šurinová, M., Husáková, I., Brabec, J., 2018. Strong fluctuations in aboveground population size do not limit genetic diversity in populations of an endangered biennial species. Oecologia 187, 863-872.
Myers, N., Mittermeier, R.A., Mittermeier, C.G., da Fonseca, G.A., Kent, J., 2000. Biodiversity hotspots for conservation priorities. Nature 403, 853-858.
Nagalingum, N.S., Marshall, C.R., Quental, T.B., Rai, H.S., Little, D.P., Mathews, S., 2011. Recent synchronous radiation of a living fossil. Science 334, 796.
Petit, R., Duminil, J., Fineschi, S., Hampe, A., Salvini, D., Giovanni Giuseppe, V., 2005. Invited review:comparative organization of chloroplast, mitochondrial and nuclear diversity in plant populations. Mol. Ecol. 14, 689-701.
Nei, M., 1987. Molecular Evolutionary Genetics. Columbia University Press, New York, USA.
Peakall, R., Smouse, P.E., 2012. GenAlEx 6.5:genetic analysis in Excel. Population genetic software for teaching and research-an update. Bioinformatics 28, 2537-2539. https://doi.org/10.1093/bioinformatics/bts460.
Petit, R., Abdelhamid, E.M., Pons, O., 2008. Identifying populations for conservation on the basis of genetic markers. Conserv. Biol. 12, 844-855.
Piry, S., Luikart, G., Cornuet, J., 1999. Computer note. BOTTLENECK:a computer program for detecting recent reductions in the effective size using allele frequency data. Hereditas 90, 502-503.
Pons, Peti, R.J., 1996. Measwring and testing genetic differentiation with ordered versus unordered alleles. Genetics 144, 1237-1245.
Pritchard, J.K., Stephens, M., Rosenberg, N.A., Donnelly, P., 2000. Association mapping in structured populations. Am. J. Hum. Genet. 67, 170-181.
Rambaut, A., Drummond, A.J., Xie, D., Baele, G., Suchard, M.A., 2018. Posterior summarisation in Bayesian phylogenetics using Tracer 1.7. Systematic Biology. syy032 https://doi.org/10.1093/sysbio/syy032.
Rauch, E.M., Bar-Yam, Y., 2004. Theory predicts the uneven distribution of genetic diversity within species. Nature 431, 449-452.
Reisch, C., Bernhardt-Römermann, M., 2014. The impact of study design and life history traits on genetic variation of plants determined with AFLPs. Plant Ecol. 215, 1493-1511.
Ren, G., Mateo, R.G., Liu, J., Suchan, T., Alvarez, N., Guisan, A., Conti, E., Salamin, N., 2017. Genetic consequences of Quaternary climatic oscillations in the Himalayas:Primula tibetica as a case study based on restriction site-associated DNA sequencing. New Phytol. 213, 1500-1512.
Rozas, J., 2009. DNA sequence polymorphism analysis using DnaSP. Methods Mol. Biol. 537, 337-350.
Salas-Leiva, D.E., Meerow, A.W., Calonje, M., Griffith, M.P., Francisco-Ortega, J., Nakamura, K., Stevenson, D.W., Lewis, C.E., Namoff, S., 2013. Phylogeny of the cycads based on multiple single-copy nuclear genes:congruence of concatenated parsimony, likelihood and species tree inference methods. Ann. Bot. 112, 1263-1278.
Sangin, P., Lindstrom, A., Kokubugata, G., Chaiprasongsuk, M., Mingmuang, M., 2010. Phylogenetic relationships within Cycadaceae inferred from non-coding regions of chloroplast DNA. Kasetsart J. (Nat. Sci.) 44, 544-557.
Schneider, S., Roessli, D., Excoffier, L., 2000. ARLEQUIN:a software for population genetics data analysis. Evol. Bioinform. Online 1.
Schou, M.F., Loeschcke, V., Bechsgaard, J., Schlotterer, C., Kristensen, T.N., 2017. Unexpected high genetic diversity in small populations suggests maintenance by associative overdominance. Mol. Ecol. 26, 6510-6523.
Segarra-Moragues, J., Palop-Esteban, M., Gonzalez-Candelas, F., Catalan, P., 2005. On the verge of extinction:genetics of the critically endangered Iberian plant species, Borderea chouardii (Dioscoreaceae) and implications for conservation management. Mol. Ecol. 14, 969-982.
Selwood, K.E., McGeoch, M.A., Mac Nally, R., 2015. The effects of climate change and land-use change on demographic rates and population viability. Biol. Rev. Camb. Philos. Soc. 90, 837-853.
Shaw, J., Lickey, E., Beck, J.T., 2005. The tortoise and the hare II:relative utility of 21 noncoding chloroplast DNA sequences for phylogenetic analysis. Am. J. Bot. 92, 142-166.
Swindell, S.R., Plasterer, T.N., 1997. SEQMAN. In:Swindell, S.R. (Ed.), Sequence Data Analysis Guidebook. Springer New York, Totowa, NJ, pp. 75-89.
Swofford, D.L., 2002. PAUP^*:Phylogenetic Analysis Using Parsimony (And Other Methods), Version 4.0b10. Sinauer Associates, Inc, Sunderland, Massachusetts.
Tang, Y.L., Su, Z.X., 2004. The research actuality and prospect of a rare and endangered plant named Cycas panzhihuaensis. J. Shaanxi Normal Univ. (Nat. Sci. Ed.) 18, 87-92 (In Chinese).
Thompson, J.D., Higgins, D.G., Gibson, T.J., 1994. Clustal W:improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position specific gap penalties and weight matrix choice. Nucleic Acids Res. 22, 4673-4680.
Wang, H.C., 2016. Characteristics of Cycas panzhihuaensis community in Pudu valley of Yunnan. For. Inventory Plan. 41, 32-39 (In Chinese with English abstract).
Wang, Q., Li, C.L., Yang, S.Y., Huang, R., Chen, F., 1997. Pollination biology of Cycas panzhihuaensis L. Zhou et S. Y. Yang. Acta Bot. Sin. 39, 156-163 (In Chinese with English abstract).
Wang, Z.F., Ye, W.H., Cao, H.L., Li, Z.C., Peng, S.L., 2008. Identification and characterization of EST-SSRs and cpSSRs in endangered Cycas hainanensis. Conserv. Genet. 9, 1079-1081.
Wang, J., Wang, Y.Y., Zhou, H., Gong, Z.D., Shi, M.M., Huang, R.R., Na, H.Y., 2010. ISSR analysis on genetic diversity of Cycas panzhihuaensisi L. Zhou et S. Y. Yang. J. Sichuan Univ. (Nat. Sci. Ed.) 47, 366-370 (In Chinese with English abstract).
Wang, Y.Y., Zhou, H., Su, B., Huang, R., Wu, J., Na, H.Y., 2011. Study on seed coat structure and trachary elements in xylems of Cycas panzhihuaensis L. Zhou et S. Y. Yang. J Sichuan Univ (Nat Sci Ed) 48, 247-252 (In Chinese with English abstract).
Waples, R.S., Do, C., 2008. ldne:a program for estimating effective population size from data on linkage disequilibrium. Mol. Ecol. Resour. 8, 753-756.
Wood, J., Yates, M., Fraser, D., 2016. Are heritability and selection related to population size in nature? Meta-analysis and conservation implications. Evol. Appl. 9, 640-657.
Wright, S., 1931. Evolution in mendelian populations. Genetics 16, 97.
Wu, C.S., Wang, Y.N., Liu, S.M., Chaw, S.M., 2007. Chloroplast genome (cpDNA) of Cycas taitungensis and 56 cp protein-coding genes of Gnetum parvifolium:insights into cpDNA evolution and phylogeny of extant seed plants. Mol. Biol. Evol. 24, 1366-1379.
Yang, Y., Li, Y., Li, L.F., Ge, X.J., Gong, X., 2008. Isolation and characterization of microsatellite markers for Cycas debaoensis Y. C. Zhong et C. J. Chen (Cycadaceae). Mol. Ecol. Resour. 8, 913-915.
Yang, Z.Y., Yi, T.S., Zeng, L.Q., Xun, G., 2014. The population genetic structure and diversification of Aristolochia delavayi (Aristolochiaceae), an endangered species of the dry hot valleys of the Jinsha River, Southwestern China. Botany 92, 579-587.
Yang, Y.Q., Huang, B.H., Yu, Z.X., Liao, P.C., 2015. Inferences of demographic history and fine-scale landscape genetics in Cycas panzhihuaensis and implications for its conservation. Tree Genet. Genom. 11, 78.
Yang, J., Zhang, Z., Shen, Z., Ou, X., Geng, Y., Yang, M., 2016. Review of research on the vegetation and environment of dry-hot valleys in Yunnan. Biodivers. Sci. 24, 462-474 (In Chinese with English abstract).
Yang, R., Feng, X., Gong, X., 2017. Genetic structure and demographic history of Cycas chenii (Cycadaceae), an endangered species with extremely small populations. Plant Diver 39, 44-51.
Yu, W.B., 2015. Floral and Reproductive Ecology of Cycas panzhihuaensis. ATBC Asia Pacific Chapter Meeting.
Yu, Z.X., Yang, Y.Q., Liu, J., Gong, L.L., Zhan, C.L., 2007. Preliminary experimenton propagation of Cycas panzhihuaensis. J. Southwest Forestry Coll. 27, 36-41 (In Chinese).
Zhang, F.M., 2012. Conservation Genetics of Cycas Panzhihuaensis. Kunming Institute of Botany, Chinese Academy of Sciences.
Zhang, M., Wang, Z.F., Jian, S.G., Ye, W.H., Cao, H.L., Zhu, P., Li, L., 2009. Isolation and characterization of microsatellite markers for Cycas hainanensis C. J. Chen(Cycadaceae). Conserv. Genet. 10, 1175-1176.
Zhang, F.M., Su, T., Yang, Y., Zhai, Y.H., Ji, Y.H., Chen, S., 2010. Development of seven novel EST-SSR markers from Cycas panzhihuaensis (Cycadaceae). Am. J. Bot. 97, 159-161.
Zhang, Q.Q., Zhao, Y.J., Gong, X., 2011a. Genetic variation and phylogeography of Psammosilene tunicoides (Caryophyllaceae), a narrowly distributed and endemic species in south-western China. Aust. J. Bot. 59, 450-459.
Zhang, T.C., Comes, H.P., Sun, H., 2011b. Chloroplast phylogeography of Terminalia franchetii (Combretaceae) from the eastern Sino-Himalayan region and its correlation with historical river capture events. Mol. Phylogenet. Evol. 60, 1-12.
Zhao, Y.J., Gong, X., 2015. Diversity and conservation of plant species in dry valleys, southwest China. Biodivers. Conserv. 24, 2611-2623.
Zheng, Y., Liu, J., Gong, X., 2016. Tectonic and climatic impacts on the biota within the Red River Fault, evidence from phylogeography of Cycas dolichophylla(Cycadaceae). Sci. Rep. 6, 33540.
Zheng, Y., Liu, J., Feng, X.Y., Gong, X., 2017. The distribution, diversity, and conservation status of Cycas in China. Ecol. Evol. 7, 3212-3224.
Zhou, L., Yang, S.Y., Fu, L.G., Cheng, S.Z., 1981. Two new species of Cycas from Sichuan. Acta Phytotaxon. Sin. 19, 335-338 (In Chinese).
Zhou, H., Wang, J., Huang, R., Na, H.Y., 2009. Callus induction and browning inhibition in Cycas panzhihuaensis L. Zhou et S. Y. Yang. J. Sichuan Univ. (Nat. Sci. Ed.) 46, 849-852 (In Chinese with English abstract).

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