Skip to main content
SpringerLink
Log in

Geographic mosaics of rice domestication in the lower Yangtze River indicated by morphological characteristics of rice bulliform phytoliths

  • Research
  • Published:
Archaeological and Anthropological Sciences Aims and scope Submit manuscript

Abstract

The lower Yangtze River valley has widely been regarded as centres of rice domestication, tracing back to 10,000 cal a BP or even earlier in the late Pleistocene. Despite recent advances in both evidence of genetics and archaeology had shed light on the process of rice domestication, including its initiation, acceleration, and completion, the spatial pattern and intra-regional differences of rice domestication in the lower Yangtze River remain unclear. Here, rice bulliform phytoliths were selected as a proxy of the domestication trait and applied to Jingtoushan, Hemudu, Yushan and Xiawangdu sites, ranging from 8000 to 5000 cal a BP in the Ningshao Plain, along with accumulated phytolith data in the Jinqu Basin and Taihu Plain. Rice domestication in the lower Yangtze River exhibited a geographic mosaic pattern rather than the presumed synchronous process among different regions. Rice domestication was initiated during the Shangshan culture (10–8.5 cal ka BP) in the Jinqu Basin and increased rapidly, which reached even higher level than the subsequent Jingtoushan culture (8.3–7.8 cal ka BP) in the Ningshao Plain. During the middle Holocene, rice domestication in the Taihu Plain was generally higher than that in the contemporaneous Ningshao Plain which may finish hundreds of years later. In contrast to the accomplishment of rice domestication around 6000 cal a BP in the Taihu Plain, the delayed process of rice domestication in the Ningshao Plain may result from frequent marine inundation induced by sea-level fluctuation during the Jingtoushan and Hemudu cultures (7–5 cal ka BP).

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7

Similar content being viewed by others

Data availability

All study data are included in the article.

References

  • Alamin M, Zeng DD, Qin R, Sultana MH, Jin XL, Shi CH (2017) Characterization and fine mapping of SFL1, a gene controlling screw flag leaf in rice. Plant Mol Biol Report 35:491–503

    Article  CAS  Google Scholar 

  • Allaby RG, Fuller DQ, Brown TA (2008) The genetic expectations of a protracted model for the origins of domesticated crops. Proc Natl Acad Sci U S A 105:13982–13986

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  • Allaby RG, Stevens C, Lucas L, Maeda O, Fuller DQ (2017) Geographic mosaics and changing rates of cereal domestication. Philos Trans R Soc Lond B Biol Sci 372:20160429

    Article  PubMed  PubMed Central  Google Scholar 

  • Arranz-Otaegui A, Colledge S, Zapata L, Teira-Mayolini LC, Ibáñez JJ (2016) Regional diversity on the timing for the initial appearance of cereal cultivation and domestication in southwest Asia. Proc Natl Acad Sci U S A 113:14001–14006

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  • Dai JQ, Deng LJ, Feng D, Zhao XS, Wang HM, Li XM, Xiao L, Zhang XY, Chen J, Li MT, Chen ZY, Liu Y, Sun QL (2022) Changes of Neolithic subsistence in south Hangzhou Bay coast, eastern China: an adaptive strategy to landscape processes. Front Plant Sci 13:1000583

    Article  PubMed  PubMed Central  Google Scholar 

  • Deng ZH (2015) A study of the prehistoric agriculture in the middle and lower Han River valley. School of Archaeology and Museology, Peking University, Beijing

  • Fujiwara H (1993) Research into the history of rice cultivation using plant opal analysis. In: Pearsall DM, Piperno DR (eds) Current research in phytolith analysis: applications in archaeology and paleoecology. The University Museum of Archaeology and Anthropology, University of Pennsylvania, Philadelphia, pp 147–158

    Google Scholar 

  • Fuller DQ (2011) Pathways to Asian civilizations: tracing the origins and spread of rice and rice cultures. Rice 4:78–92

    Article  Google Scholar 

  • Fuller DQ, Qin L (2009) Water management and labour in the origins and dispersal of Asian rice. World Archaeol 41:88–111

    Article  Google Scholar 

  • Fuller DQ, Harvey E, Qin L (2007) Presumed domestication? Evidence for wild rice cultivation and domestication in the fifth millennium BC of the Lower Yangtze region. Antiquity 81:316–331

    Article  Google Scholar 

  • Fuller DQ, Qin L, Zheng YF, Zhao ZJ, Chen XG, Hosoya LA, Sun GP (2009) The domestication process and domestication rate in rice: spikelet bases from the Lower Yangtze. Science 323:1607–1610

    Article  ADS  CAS  PubMed  Google Scholar 

  • Fuller DQ, Sato Y-I, Castillo C, Qin L, Weisskopf AR, Kingwell-Banham EJ, Song JX, Ahn S-M, van Etten J (2010) Consilience of genetics and archaeobotany in the entangled history of rice. Archaeol Anthropol Sci 2:115–131

    Article  Google Scholar 

  • Fuller DQ, Willcox G, Allaby RG (2011) Cultivation and domestication had multiple origins: arguments against the core area hypothesis for the origins of agriculture in the Near East. World Archaeol 43:628–652

    Article  Google Scholar 

  • Fuller DQ, Asouti E, Purugganan MD (2012) Cultivation as slow evolutionary entanglement: comparative data on rate and sequence of domestication. Veg Hist Archaeobot 21:131–145

    Article  Google Scholar 

  • Fuller DQ, Denham T, Arroyo-Kalin M, Lucas L, Stevens CJ, Qin L, Allaby RG, Purugganan MD (2014) Convergent evolution and parallelism in plant domestication revealed by an expanding archaeological record. Proc Natl Acad Sci U S A 111:6147–6152

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  • Fuller DQ, Denham T, Kistler L, Stevens C, Larson G, Bogaard A, Allaby R (2022) Progress in domestication research: explaining expanded empirical observations. Quat Sci Rev 296:107737

    Article  Google Scholar 

  • Fuller DQ (2020) Transitions in productivity: rice intensification from domestication to urbanisation. Archaeol Int 23:88–103

    Article  Google Scholar 

  • Gao Y (2012) A study of plant remains and the Neolithic subsistence in Taihu Lake region. School of Archaeology and Museology, Peking University, Beijing

  • Gross BL, Zhao ZJ (2014) Archaeological and genetic insights into the origins of domesticated rice. Proc Natl Acad Sci U S A 111:6190–6197

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  • He KY, Lu HY, Zheng YF, Zhang JP, Xu DK, Huan XJ, Wang JH, Lei S (2018) Middle-Holocene sea-level fluctuations interrupted the developing Hemudu culture in the lower Yangtze River, China. Quat Sci Rev 188:90–103

    Article  ADS  Google Scholar 

  • He KY, Lu HY, Li YN, Ding FY, Zhang JP, Wang C (2020a) Cultural response to Middle Holocene sea-level fluctuations in eastern China: a multi-proxy approach. Boreas 49:71–88

    Article  Google Scholar 

  • He KY, Lu HY, Zheng HB, Yang Q, Sun GP, Zheng YF, Cao YT, Huan XJ (2020b) Role of dynamic environmental change in sustaining the protracted process of rice domestication in the lower Yangtze River. Quat Sci Rev 242:106456

    Article  Google Scholar 

  • Huan XJ, Lu HY, Wang C, Tang XG, Zuo XX, Ge Y, He KY (2015) Bulliform phytolith research in wild and domesticated rice paddy soil in south China. PLoS ONE 10:e0141255

    Article  PubMed  PubMed Central  Google Scholar 

  • Huan XJ, Lu HY, Jiang LP, Zuo XX, He KY, Zhang JP (2021) Spatial and temporal pattern of rice domestication during the early Holocene in the lower Yangtze region. Holocene 31:1366–1375

    Article  ADS  Google Scholar 

  • Innes JB, Zong YQ, Chen ZY, Chen C, Wang ZH, Wang H (2009) Environmental history, palaeoecology and human activity at the early Neolithic forager/cultivator site at Kuahuqiao, Hangzhou, eastern China. Quat Sci Rev 28:2277–2294

    Article  ADS  Google Scholar 

  • The Institute of Archaeology, China Academy of Social Sciences (2010) Chinese Archaeology: Neolithic, China Social Sciences Press, Beijing (in Chinese)

  • Ishikawa R, Castillo CC, Fuller DQ (2020) Genetic evaluation of domestication-related traits in rice: implications for the archaeobotany of rice origins. Archaeol Anthropol Sci 12:197

    Article  Google Scholar 

  • Jiang LP (2013) The early neolithic age of the Qiantangjiang Basin and its cultural lineage. Southeast Culture 6:44–53 (in Chinese with English abstract)

    Google Scholar 

  • Kovach MJ, Sweeney MT, McCouch SR (2007) New insights into the history of rice domestication. Trends Genet 23:578–587

    Article  CAS  PubMed  Google Scholar 

  • Li L, Shi ZY, Li L, Shen GZ, Wang XQ, An LS, Zhang JL (2010) Overexpression of ACL1 (abaxially curled leaf 1) increased bulliform cells and induced abaxial curling of leaf blades in rice. Mol Plant 3:807–817

    Article  CAS  PubMed  Google Scholar 

  • Liu B, Wang NY, Chen MH, Wu XH, Mo DW, Liu JG, Xu SJ, Zhuang YJ (2017) Earliest hydraulic enterprise in China, 5,100 years ago. Proc Natl Acad Sci U S A 114:13637–13642

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  • Liu Y, Deng L, He J, Jiang R, Fan D, Jiang X, Jiang F, Li M, Chen J, Chen Z, Sun Q (2020) Early to middle Holocene rice cultivation in response to coastal environmental transitions along the South Hangzhou Bay of eastern China. Paleogeogr Paleoclimatol Paleoecol 555:109872

    Article  Google Scholar 

  • Londo JP, Chiang YC, Hung KH, Chiang TY, Schaal BA (2006) Phylogeography of Asian wild rice, Oryza rufipogon, reveals multiple independent domestications of cultivated rice, Oryza sativa. Proc Natl Acad Sci U S A 103:9578–9583

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  • Lu HY (2022) Periodic climate change and human adaptation. Acta Anthropologica Sinica 41:731–748 (in Chinese with English abstract)

    Google Scholar 

  • Lu HY, Liu ZX, Wu NQ, Berné S, Saito Y, Liu BZ, Wang L (2002) Rice domestication and climatic change: phytolith evidence from East China. Boreas 31:378–385

    Article  Google Scholar 

  • Lu HY, Wu NQ, Yang XD, Jiang H, Liu KB, Liu TS (2006) Phytoliths as quantitative indicators for the reconstruction of past environmental conditions in China I: phytolith-based transfer functions. Quat Sci Rev 25:945–959

    Article  ADS  Google Scholar 

  • Ma YC, Yang XY, Huan XJ, Wang WW, Ma ZK, Li Z, Sun GP, Jiang LP, Zhuang YJ, Lu HY (2016) Rice bulliform phytoliths reveal the process of rice domestication in the Neolithic Lower Yangtze River region. Quat Int 426:126–132

    Article  Google Scholar 

  • Maeda O, Lucas L, Silva F, Tanno K-I, Fuller DQ (2016) Narrowing the harvest: increasing sickle investment and the rise of domesticated cereal agriculture in the Fertile Crescent. Quat Sci Rev 145:226–237

    Article  ADS  Google Scholar 

  • Ningbo Chorography Codification Committee (1995) Ningbo Chorography, Zhonghua Book Company, Beijing (in Chinese)

  • Pearsall DM, Piperno DR, Dinan EH, Umlauf M, Zhao ZJ, Benfer RA (1995) Distinguishing rice (Oryza sativa Poaceae) from wild Oryza species through phytolith analysis: results of preliminary research. Econ Bot 49:183–196

    Article  Google Scholar 

  • Piperno DR (1988) Phytolith analysis: an archaeological and geological perspective. Academic Press, London

    Google Scholar 

  • Qin JG, Taylor D, Atahan P, Zhang XR, Wu GX, Dodson J, Zheng HB, Itzstein-Davey F (2011) Neolithic agriculture, freshwater resources and rapid environmental changes on the lower Yangtze, China. Quat Res 75:55–65

    Article  Google Scholar 

  • Qiu ZW, Jiang LP, Wang CS, Hill DV, Wu Y (2019) New evidence for rice cultivation from the early Neolithic Hehuashan site. Archaeol Anthropol Sci 11:1259–1272

    Article  Google Scholar 

  • Renfrew C, Liu B (2018) The emergence of complex society in China: the case of Liangzhu. Antiquity 92:975–990

    Article  Google Scholar 

  • Riehl S, Zeidi M, Conard NJ (2013) Emergence of agriculture in the foothills of the Zagros Mountains of Iran. Science 341:65–67

    Article  ADS  CAS  PubMed  Google Scholar 

  • Shao KL, Zhang JP, Lu HY, Gu ZY, Xu B, Zheng HB, Sun GP, Huan XJ, He KY, Zou YF, Wu NQ (2021) Process of rice domestication in relation to Holocene environmental changes in the Ningshao Plain, lower Yangtze. Geomorphology 381:107650

    Article  Google Scholar 

  • Silva F, Stevens CJ, Weisskopf A, Castillo C, Qin L, Bevan A, Fuller DQ (2015) Modelling the geographical origin of rice cultivation in Asia using the rice archaeological database. PLoS ONE 10:e0137024

    Article  PubMed  PubMed Central  Google Scholar 

  • Svizzero S (2021) How gathering wild rice under human-mediated drought stress could have inadvertently paved the way to Asian rice incipient domestication and cultivation. Holocene 32:226–231

    Article  ADS  Google Scholar 

  • Tang XG, Lu HY, Cao ZB, Xie JS (2022) Morphological characteristics of homozygous wild rice phytoliths and their significance in the study of rice origins. Sci China-Earth Sci 65:107–117

    Article  ADS  Google Scholar 

  • Thompson JN (2005) The geographic mosaic of coevolution. University of Chicago Press, Chicago

    Book  Google Scholar 

  • Wang ZH, Ryves DB, Lei S, Nian XM, Lv Y, Tang L, Wang L, Wang JH, Chen J (2018) Middle Holocene marine flooding and human response in the south Yangtze coastal plain, East China. Quat Sci Rev 187:80–93

    Article  ADS  Google Scholar 

  • Wang C, Lu HY, Zhang JP, Mao LM, Ge Y (2019) Bulliform phytolith size of rice and its correlation with hydrothermal environment: a preliminary morphological study on species in Southern China. Front Plant Sci 10:1037

    Article  PubMed  PubMed Central  Google Scholar 

  • Weisskopf A, Qin L, Ding JL, Ding P, Sun GP, Fuller DQ (2015) Phytoliths and rice: from wet to dry and back again in the Neolithic Lower Yangtze. Antiquity 89:1051–1063

    Article  Google Scholar 

  • Willcox G (2013) The roots of cultivation in southwestern Asia. Science 341:39–40

    Article  ADS  CAS  PubMed  Google Scholar 

  • Wu Y, Jiang LP, Zheng YF, Wang CS, Zhao ZJ (2014) Morphological trend analysis of rice phytolith during the early Neolithic in the Lower Yangtze. J Archaeol Sci 49:326–331

    Article  Google Scholar 

  • Xu YT, Lin Z, Jiang LP (2016) Relationship between the distribution of Shangshan culture and geographic factors. Cultural Relics in Southern China 3:131–138 (in Chinese with English absract)

    Google Scholar 

  • Yang SQ, Li WQ, Miao H, Gan PF, Qiao L, Chang YL, Shi CH, Chen KM (2016) REL2, a gene encoding an unknown function protein which contains DUF630 and DUF632 domains controls leaf rolling in rice. Rice 9:37

    Article  PubMed  PubMed Central  Google Scholar 

  • Zhang JJ, Wu SY, Jiang L, Wang JL, Zhang X, Guo XP, Wu CY, Wan JM (2015) A detailed analysis of the leaf rolling mutant sll2 reveals complex nature in regulation of bulliform cell development in rice (Oryza sativa L.). Plant Biol 17:437–448

    Article  CAS  PubMed  Google Scholar 

  • Zhao ZJ (2010) New data and new issues for the study of origin of rice agriculture in China. Archaeol Anthropol Sci 2:99–105

    Article  Google Scholar 

  • Zhao ZJ, Piperno DR (2000) Late Pleistocene/Holocene Environments in the middle Yangtze River Valley, China and rice (Oryza sativa L.) domestication: the phytolith evidence. Geoarchaeology 15:203–222

    Article  Google Scholar 

  • Zhao ZJ (2023) Agricultural origins from the perspective of evolutionary biology: the origins of rice farming as a case study. Archaeology 2:112–120 (in Chinese with English abstract)

    Google Scholar 

  • Zhejiang Provincial Institute of Cultural Relics and Archaeology, Ningbo Institute of Cultural Heritage Management, Yuyao Hemudu Site Museum (2021) Brief report on the excavatation of the Neolithic site at Jingtoushan in Yuyao City, Zhejiang. Archaeology 7:3–26 (in Chinese with English abstract)

    Google Scholar 

  • Zhejiang Provincial Institute of Cultural Relics and Archaeology, Ningbo Institute of Cultural Heritage Management, Yuyao Hemudu Site Museum (2023) Brief report on the excavation of paddy remains at Shiao Site, Yuyao City, Zhejiang Province. Archaeology 5:3–21 (in Chinese with English abstract)

    Google Scholar 

  • Zheng YF, Matsui A, Fujiwara H (2003) Phytoliths of rice detected in the Neolithic sites in the valley of the Taihu Lake in China. Environ Archaeol 8:177–183

    Article  Google Scholar 

  • Zheng YF, Jiang LP, Zheng JM (2004) Study on the remains of ancient rice from Kuahuqiao site in Zhejiang Province. Chin J Rice Sci 18:119–124 (in Chinese with English abstract)

    ADS  Google Scholar 

  • Zheng YF, Sun GP, Chen XG (2007) Characteristics of the short rachillae of rice from archaeological sites dating to 7000 years ago. Chinese Sci Bull 52:1654–1660

    Article  ADS  Google Scholar 

  • Zheng YF, Sun GP, Chen XG (2011) Response of rice cultivation to fluctuating sea level during the Mid-Holocene. Chinese Sci Bull 57:370–378

    Article  ADS  Google Scholar 

  • Zheng YF, Crawford GW, Jiang LP, Chen XG (2016) Rice domestication revealed by reduced shattering of archaeological rice from the Lower Yangtze valley. Sci Rep 6:28136

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  • Zheng XQ, Lei S, Wang JH, Zhao ZJ (2019) Analysis of flotation results from the Yushan site in Ningbo City. Agricultural Archaeology 6:21–27 (in Chinese with English abstract)

    Google Scholar 

  • Zong YQ, Chen ZY, Innes JB, Chen C, Wang ZH, Wang H (2007) Fire and flood management of coastal swamp enabled first rice paddy cultivation in east China. Nature 449:459–462

    Article  ADS  CAS  PubMed  Google Scholar 

  • Zong YQ, Innes JB, Wang ZH, Chen ZY (2011) Mid-Holocene coastal hydrology and salinity changes in the east Taihu area of the lower Yangtze wetlands, China. Quat Res 76:69–82

    Article  CAS  Google Scholar 

  • Zong YQ, Innes JB, Wang ZH, Chen ZY (2012) Environmental change and Neolithic settlement movement in the lower Yangtze wetlands of China. Holocene 22:659–673

    Article  ADS  Google Scholar 

  • Zou LP, Sun XH, Zhang ZG, Liu P, Wu JX, Tian CJ, Qiu JL, Lu TG (2011) Leaf rolling controlled by the homeodomain leucine zipper class IV gene Roc5 in rice. Plant Physiol 156:1589–1602

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  • Zuo XX, Lu HY, Li Z, Song B, Xu DK, Zou YF, Wang C, Huan XJ, He KY (2016) Phytolith and diatom evidence for rice exploitation and environmental changes during the early mid-Holocene in the Yangtze Delta. Quat Res 86:304–315

    Article  Google Scholar 

  • Zuo XX, Lu HY, Jiang LP, Zhang JP, Yang XY, Huan XJ, He KY, Wang C, Wu NQ (2017) Dating rice remains through phytolith carbon-14 study reveals domestication at the beginning of the Holocene. Proc Natl Acad Sci U S A 114:6486–6491

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

We would like to thank Deke Xu, Anning Cui and Can Wang for their assistance in sample collection. We are grateful to Xiujia Huan for providing the data of Shangshan culture. We would like to thank Editage (www.editage.cn) for English language editing.

Funding

This research was supported by the National Natural Science Foundation of China (Nos. 41830322, 41902187, and T2192954), China Postdoctoral Science Foundation (Nos. 2020M670444), the Fundamental Research Funds for the Central Universities and the Innovative Research Project of the Sichuan University (No. 2023CX11).

Author information

Authors and Affiliations

  1. Center for Archaeological Science, Sichuan University, Chengdu, 610064, China

    Keyang He & Xiaoshan Yu

  2. School of Archaeology and Museology, Sichuan University, Chengdu, 610064, China

    Keyang He & Xiaoshan Yu

  3. Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China

    Keyang He, Jianping Zhang & Houyuan Lu

  4. Zhejiang Provincial Institute of Cultural Relics and Archaeology, Hangzhou, 310014, China

    Yonglei Wang, Yunfei Zheng & Guoping Sun

  5. Ningbo Municipal Institute of Cultural Relics and Archaeology, Ningbo, 315012, China

    Shao Lei & Yongning Li

  6. University of Chinese Academy of Sciences, Beijing, 100049, China

    Houyuan Lu

Authors
  1. Keyang He
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Yonglei Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Yunfei Zheng
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Guoping Sun
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Shao Lei
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Yongning Li
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Xiaoshan Yu
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Jianping Zhang
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. Houyuan Lu
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

HL and KH designed the research. YW, GS, SL, YL, and YZ assisted the samples collection. KH and XY performed the experiment. KH and JZ carried out the data analysis. KH and HL wrote and revised the manuscript. All authors read and approved the final manuscript.

Corresponding authors

Correspondence to Keyang He or Houyuan Lu.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary file1 (DOCX 4556 KB)

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

He, K., Wang, Y., Zheng, Y. et al. Geographic mosaics of rice domestication in the lower Yangtze River indicated by morphological characteristics of rice bulliform phytoliths. Archaeol Anthropol Sci 16, 28 (2024). https://doi.org/10.1007/s12520-024-01936-3

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s12520-024-01936-3

Keywords

Search

Navigation