Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-25T04:16:06.773Z Has data issue: false hasContentIssue false

Genetic erosion over time of rice landrace agrobiodiversity

Published online by Cambridge University Press:  25 November 2008

Brian V. Ford-Lloyd*
Affiliation:
School of Biosciences, University of Birmingham, Edgbaston, BirminghamB15 2TT, UK
Darshan Brar
Affiliation:
International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines
Gurdev S. Khush
Affiliation:
University of California, 39399 Blackhawk Place, Davis, CA95616-7008, USA
Michael T. Jackson
Affiliation:
International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines
Parminder S. Virk
Affiliation:
International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines
*
*Corresponding author. E-mail: [email protected]

Abstract

Changes in global biodiversity at the genetic level have proved difficult to determine for most organisms because of lack of standardized, repeated or historical data; this hampers the attempts to meet the convention on biological diversity (CBD) 2010 targets of reducing loss of genetic diversity, particularly of crop species. For rice, where germplasm and genetic data have been collected throughout South and Southeast Asia over many decades, contrary to popular opinion, we have been unable to detect a significant reduction of available genetic diversity in our study material. This absence of a decline may be viewed positively; over the 33-year timescale of our study, genetic diversity amongst landraces grown in traditional agricultural systems was still sufficiently abundant to be collected for ex situ conservation. However, if significant genetic erosion does take place in the future as a result of accelerating global warming and/or major changes in land use or agricultural practices, will it be catastrophic or gradual, and how will it be detected? We have shown a strong link between numbers of landraces collected (and therefore extant) and genetic diversity; hence, we have a clear indicator to detect loss of genetic diversity in the future. Our findings lend considerable support for ex situ conservation of germplasm; the more than substantial genetic resources already in genebanks are now safe. On the other hand, it is the germplasm growing in farmers' fields, continually adapting genetically to changing environmental conditions and evolving novel genetic forms, whose future has been much less certain but can now be effectively monitored using our criteria.

Type
Research Article
Copyright
Copyright © NIAB 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Appa Rao, S, Bounphanousay, C, Schiller, JM, Alcantara, AP and Jackson, MT (2002) Naming traditional rice varieties by farmers in the Lao PDR. Genetic Resources and Crop Evolution 49: 8388.CrossRefGoogle Scholar
Balmford, A, Bennun, L, ten Brink, B, Cooper, D, Cote, IM, Crane, P, Dobson, A, Dudley, N, Dutton, I, Green, RE, Gregory, RD, Harrison, J, Kennedy, ET, Kremen, C, Leader-Williams, N, Lovejoy, TE, Mace, G, May, R, Mayaux, P, Morling, P, Phillips, J, Redford, K, Ricketts, TH, Rodriguez, JP, Sanjayan, M, Schei, PJ, van Jaarsveld, AD and Walther, BA (2005) The convention on biological diversity's 2010 target. Science 307: 212213.CrossRefGoogle ScholarPubMed
Bezancon, G, Pham, J-L, Deu, M, Vigouroux, Y, Sagnard, F, Mariac, C, Kapran, I, Mamadou, A, Gerard, B, Ndjeunga, J and Chantereau, J (2008) Changes in the diversity and geographic distribution of cultivated millet (Pennisetum glaucum (L.) R. Br.) and sorghum (Sorghum bicolor (L.) Moench) varieties in Niger between 1976 and 2003. Genetic Resources and Crop Evolution DOI 10.1007/s10722-008-9357-3.Google Scholar
Cai, H-W, Wang, X-K and Morishima, H (2004) Comparison of population genetic structures of common wild rice (Oryza rufipogon Griff.), as revealed by analyses of quantitative traits, allozymes, and RFLPs. Heredity 92: 409417.CrossRefGoogle ScholarPubMed
Camacho-Villa, TC, Maxted, N, Scholten, M and Ford-Lloyd, B (2006) Defining and identifying crop landraces. Plant Genetic Resources 3: 373384.CrossRefGoogle Scholar
Donald, PF, Sanderson, FJ, Burfield, IJ, Bierman, SM, Gregory, RD and Waliczky, Z (2007) International conservation policy delivers benefits for birds in Europe. Science 317: 810.CrossRefGoogle ScholarPubMed
Donini, P, Law, JR, Koebner, RMD, Reeves, JC and Cooke, RJ (2000) Temporal trends in the diversity of UK wheat. Theoretical and Applied Genetics 100: 912917.Google Scholar
Esquinas-Alcazar, J (2005) Protecting crop genetic diversity for food security: political, ethical and technical challenges. Nature Reviews Genetics 6: 946953.CrossRefGoogle ScholarPubMed
Food and Agriculture Organisation (FAO)(1998) The State of the World's Plant Genetic Resources for Food and Agriculture. Rome: FAO.Google Scholar
Ford-Lloyd, BV, Newbury, HJ, Jackson, MT and Virk, PS (2001) Genetic basis for co-adaptive gene complexes in rice (Oryza sativa L.) landraces. Heredity 87: 530536.CrossRefGoogle ScholarPubMed
Glaszmann, JC, de los Reyes, BG and Khush, GS (1988) Electrophoretic variation of isozymes in plumules of rice (Oryza sativa L.) – a key to the identification of 76 alleles at 24 loci. IRRI Research Paper Series No. 134. Los Baños, Philippines: International Rice Research Institute, pp. 113.Google Scholar
Green, RE, Balmford, A, Crane, PR, Mace, GM, Reynolds, JD and Turner, RK (2005) A framework for improved monitoring of biodiversity: responses to the world summit on sustainable development. Conservation Biology 19: 5665.Google Scholar
Keisa, A, Maxted, N and Ford-Lloyd, B (2008) The assessment of biodiversity loss over time: wild legumes in Syria. Genetic Resources and Crop Evolution 55: 603612.CrossRefGoogle Scholar
Khlestkina, EK, Huang, XQ, Quenum, FJB, Chebotar, S, Röder, MS and Börner, A (2004) Genetic diversity in cultivated plants – loss or stability? Theoretical and Applied Genetics 108: 14661472.Google Scholar
Khush, GS, Brar, DS, Virk, PS, Tang, SX, Malik, SS, Busto, GA, Lee, YT, McNally, R, Trinh, LN, Jiang, Y and Shata, MAM (2003) Classifying rice germplasm by isozyme polymorphism and origin of cultivated rice. IRRI Discussion Paper Series No. 46. Los Baños, Philippines: International Rice Research Institute, p. 279.Google Scholar
Lawrence, MJ, Marshall, DF and Davies, P (1995) Genetics of genetic conservation. 1. Sample-size when collecting germplasm. Euphytica 84: 8999.Google Scholar
Leung, H, Hettel, GP and Cantrell, RP (2002) International Rice Research Institute: roles and challenges as we enter the genomics era. Trends in Plant Science 7: 139142.CrossRefGoogle ScholarPubMed
Lewis, PO and Zaykin, D (2001) Genetic data analysis: computer program for the analysis of allelic data. Version 1.0 (d16c). Free program distributed by the authors over the internet. Available at http://lewis.eeb.uconn.edu/lewishome/software.html.Google Scholar
Manifesto, MM, Schlatter, AR, Hopp, HE, Suárez, EY and Dubcovsky, J (2001) Quantitative evaluation of genetic diversity in wheat germplasm using molecular markers. Crop Science 41: 682690.Google Scholar
Nei, M (1978) Estimation of average heterozygosity and genetic distance from a small number of individuals. Genetics 89: 583590.Google Scholar
Stolton, S, Maxted, N, Ford-Lloyd, B, Kell, S and Dudley, N (2006) Food stores: using protected areas to secure crop genetic diversity. A Research Report by WWF, Equilibrium and the University of Birmingham..Google Scholar
United Nations Environment Program (UNEP) (2004) Report on the Sixth Meeting of the Conference of the Parties to the Convention on Biological Diversity United Nations Environment Program/Convention on Biological Diversity/Conference of the Parties (UNEP/CBD/COP/6/20/Part 2) Strategic Plan Decision VI/26 (CBD 2002). Available at www.biodiv.org/doc/meetings/cop/cop-06/official/cop-o6-20-part2-en.pdf.Google Scholar
Watson-Jones, SJ, Maxted, N and Ford-Lloyd, BV (2006) Population baseline data for monitoring genetic diversity loss for 2010: a case study for Brassica species in the UK. Biological Conservation 132: 490499.Google Scholar
Wilson, RJ, Thomas, CD, Fox, R, Roy, DB and Kunin, WE (2004) Spatial patterns in species distributions reveal biodiversity change. Nature 432: 393396.CrossRefGoogle ScholarPubMed
Wu, KS, Glaszmann, JC and Khush, GS (1988) Chromosomal locations of ten isozyme loci in rice (Oryza sativa L.) through trisomic analysis. Biochemical Genetics 26: 303320.Google Scholar
Supplementary material: PDF

Ford-Lloyd supplementary material

Data.pdf

Download Ford-Lloyd supplementary material(PDF)
PDF 718.5 KB
Supplementary material: PDF

Ford-Lloyd Supplementary Material

Table2.pdf

Download Ford-Lloyd Supplementary Material(PDF)
PDF 13.9 KB