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International Agrobiodiversity Congress (6 - 9 November, 2016, New Delhi) To discuss… • Journey of crops • Classical plant collectors and concepts • Status of world PGR in Gene banks • Genetic erosion – Levels, major causes • Genetic Diversity indicators (ex situ) • Assessing genetic erosion • Recommendations Journey of Crops Crops that travelled around the world along with people Wheat from Near East (Israel) Maize, Tomato, Pepper (chilli) from South America Banana from South East Asia (Malaysia) Carrots from Afghanistan Potato from Andean region, South America Onion from Central Asia (Iran) Pumpkins from Tropical America (Mexico) Classical Collectors/ Concepts • Queen Hatsheput (Egypt, 3500 years ago) – collected resin of myrrha plant (Commiphora) and frankincense (Boswellia) trees near Somalia • Christopher Columbus (Italy) – potatoes, sweet potatoes, maize, tomatoes, peanut, cassava, cacao, peppers, tobacco, beans and squashes • Thomas Jefferson (3rd President of USA) – Vanilla, tea, olives from Europe • Nicolai Vavilov (Russia) –Centres of origin • Carlos Ochoa (Peru) – Wild and endangered species of potato • John George Jack (Canada) – Tree genetic resources Classical Collectors and Concepts • Jack Harlan (USA) - Centres of diversity • Gregory WC & Krapovickas A – Groundnut • Brown WL – Maize • Hawkes JG (UK) & Otto Frankel (Australia) – PGR as a science • Zeven AC (The Netherlands) and PM Zhukovsky (Russia) – Centres of Origin. Indian Context • Emperor Ashoka (304-232 BC) patronized the establishment of fruit and shade trees in his kingdom. • Emperor Akbar (1542-1605) established a mango orchard (Lakhi Bagh) in Darbhanga, Bihar during his regime. Status of World PGR in Gene banks • Over 1750 gene banks and 2,500 botanical gardens conserve a total of 7.4 million germplasm accessions and 80,000 species respectively around the world. • Currently 870,971 samples are deposited at Svalbard, Norway by 69 gene banks. This is about one third of globally distinct accessions of 156 crop genera. Svalbard Global Seed Vault, Norway (870,971 seed samples-233 countries) Global Ex Situ holdings of commodity groups Crop Group Accessions Crop Group Accessions Cereals 3,157,578 Forages 651,024 Food legumes 1,069,897 Sugar crops 63,474 Roots and tubers 204,408 Fibre crops 169,969 Vegetables 502,889 Medicinal, aromatic 160,050 and spice crops Nuts, fruits and berries 423,401 Industrial and ornamental plants 152,325 Oil crops 181,752 others 262,993 FAO (2014) The Ten Largest germplasm collections… Institution Country Accessions NPGS (National Plant Germplasm System) USA 576,187 ICAR-NBPGR (National Bureau of Plant Genetic Resources) India 429,110 ICGR-CAAS (Institute of Crop Germplasm ResourcesChinese Academy of Agricultural Sciences) China 410,000 VIR (N I Vavilov Research Institute of Plant Industry) Russia 322,238 NIAS (National Institute of Agrobiological Science) Japan 243,463 CIMMYT (Centro Internacional de Mejoramiento de Maiz y Trigo) Mexico 164,320 IPK (Leibniz-Instiut fur Pflanzengenetik und Kulturpflazenforschung) Germany 151,408 ICARDA (International Center for Agricultural Research in the Dry Areas) Syria 147,076 IRRI (International Rice Research Institute) Philippines 124,052 ICRISAT (International Crops Research Institute for the Semi-Arid Tropics) India 119,524 Ex situ collection at CGIAR centres Centre Number of Accessions held Africa Rice 19,985 Bioversity International 1516 CIAT 64,721 CIMMYT 164,320 CIP 16,061 ICARDA 147,076 ICRAF 2005 ICRISAT 119,524 IITA 27,232 ILRI 20,229 IRRI 124,052 Holdings of commodity groups in NGB, India (As on 30 Sep.2016 - 4,29,110 accs) Crop Group Accessions Crop Group Accessions Cereals 1,59,817 Forages 6,789 Millets 57,951 Pseudo cereals 7,225 Food legumes 65,211 Fibre crops 14,368 Vegetables 25,510 Medicinal, aromatic 10,750 and spice crops Nuts & fruits 272 Ornamental plants 646 Oil crops 57,923 Agroforestry 1,642 Others (safety duplicate, trial materials) 21,006 www.nbpgr.ernet.in Can these rich Ex Situ collections be protected from Genetic Erosion? Genetic Erosion Steady loss of genetic diversity in on-farm or ex situ. The loss of variation in crops due to the modernization of agriculture. Replacement of landraces by modern productive cultivars with narrow genetic base. Catastrophic outbreaks that forced to think about genetic erosion Southern corn-leaf blight-USA Coffee rust-Brazil Genetic uniformity is the basis of vulnerability to epidemics. Genetic Erosion: Levels Loss of alleles or genes Loss of genotypes or land races Genetic Erosion: Major Causes Narrow genetic base in the original collections (Less than representative sample collected and the initial bottleneck effect). Lack of Knowledge on biology, breeding system, mode of reproduction and pattern of genetic diversity. Lack of gene flow between different populations and natural and artificial selection/interaction in heterogeneous environments. Improper management/ regeneration procedures (genetic drift and shift). Raising global temperatures and climate change. Why to prevent Genetic Erosion? • Conserved genes successfully used in mitigating major challenges. Wide range of variation will be required to meet the demands placed by the climate change and adaptation requirements in the future (FAO, 2015). • Rust resistance in wheat varieties by incorporation of single major gene that conferred resistance to specific races of rust pathogens (Borlaug, 1953) • Chromosomal translocation from rye to wheat has conferred adaptation potential to wheat in marginal environments (Borner et al. 2000) • Drought tolerant maize/stress resilient maize in Africa (Chebotar et al. 2003) Genetic Diversity Indicators in Ex situ • Number of crop species, subspecies or geographic categories adequately sampled in gene banks • Number of accessions held in the gene bank • Number of collections or gene banks • Country distribution of seed gene banks • Coverage in collections of crop diversity • Backup duplication provisions • Extent of usage and representation in core collections • Collection health, accession viability • Documentation and evaluation of collection Modified from Brown and Brubaker (2002) Indicators of genetic diversity in wild genepool • Number of wild species, subspecies or geographic subdivisions of taxa related to crops adequately sampled in the gene bank. • Coverage of species range. • Evolutionary relationships and taxonomic resolution. • Accession viability, documentation and duplication. • Number and frequency of accessions used. • ‘Prebreeding’ activities, including evaluation. Modified from Brown and Brubaker (2002) Assessing Genetic Erosion in Gene banks Factors causing genetic erosion in Gene banks • Physiological changes in seeds (Barley & Wheat –chromosome aberration, loss of seed vigour) • Inappropriate storage conditions and management procedures • Accidental errors/mixing of seed samples before regeneration • Lack of adequate financial resources for maintaining collections • Accidental destruction, fire. To continue… Factors causing genetic erosion in Gene banks • Damage of field collection (animals, natural disasters, pest outbreak) • Armed conflicts, war (ICARDA gene bank at Alleppo damaged in 2012) • Regeneration backlogs • Economic instability • Lack of resources and skills • Abiotic stresses (heat and drought), loss of samples during regeneration Genetic erosion in Gene bank collections depends on the quality and quantity of the original material stored & on the conditions under which the germplasm is maintained and regenerated. Population size at the time of collecting and at the time of regeneration • Number of accessions and their isolation during collection and at the time of regeneration are also indicators for genetic erosion. (Pigeonpea geneflow studies) • Small Populations are at risk of loss of alleles (rare allelesmissing the allele detection), increased inbreeding and extinction due to random environmental events. (Pearlmillet ??) • Direct comparison of samples collected at different times in the ex situ collections are warranted to assess the genetic erosion (Adilabad paddy) Extent of Alleles lost in Ex Situ Collections (Indicative case studies) Wheat accessions (Borner et al., 2000)-High Maize (Wen et al., 2011 ) 22% Rye accessions (Chebotar et al., 2003) – 50% Brassica oleracea (Soengas et al., 2009) – significant • Stable and unique morphological traits (initial and regenerated samples) of ex situ conserved samples. • Characterization based on standardized format (internationally agreed descriptors) Recommendations • Traits of importance to be documented exhaustively at collection time. • Define the genetic integrity at the time of collection and the method of maintenance. • Sample size at the time of collection and subsample size for regeneration should follow gene bank standards. • Evaluation of collections for traits of current importance (Iron, Zinc, recent biotic stresses, climate change etc. in paddy) for avoiding genetic drift. • Revisiting the original locations of collection to assess the extent of genetic erosion. Recommendations (Contd.) • Research on protocols and scales and indicators (individual cropwise) to maximize the genetic integrity. • Follow proper regeneration protocols (Germplasm adaptation to environment, taxonomy, reproductive biology and genetic diversity studies are to be taken up). • Modern tools may be used to estimate the genetic erosion and the resultant diversity created during conservation should also be utilized for crop improvement. Conclusion Best strategy to minimise genetic erosion combines ex situ conservation with on-theground (in situ) conservation by farmers in their agro-ecosystems and of crop wild relatives in, for example, areas protected for their environmental value. Way Forward: Genebanks Relevance • Develop standards to accommodate diversity within a variety in “DUS” Government of AP/Telangana and NGOs (WASSAN/ DDS) • Entry of tagged landraces in to CMSS (Govt subsidies, Consumption & Commercialisation – Conserved sustainably)- Ananathpur • “Navadhanyalu” several crop landraces in one packet for rainfed cultivation- Ananthapur & North Coastal AP • Organic rain-fed cultivation –Medak, Telangana Prebreeding commercialisation from genebanks (HPRC -ICRISAT) • Genebanks and crop breeders to exploit synecology and diversified agriculture concepts to create diversity • Establish urban market linkage for tagged landraces • Reintroduce in to wild and follow up