Nigel Maxted DRAFT THOUGHTS

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2 Nigel Maxted DRAFT THOUGHTS
Plant Genetic Resource Gap Analysis: targeting CWR for in situ and ex situ conservation Nigel Maxted DRAFT THOUGHTS

3 Talk Objectives Need to improve conservation through better prioritisation What is ‘Gap Analysis’ and how to apply for PGR? Proposed methodology for discussion Exemplar: Cowpea and its relative (Vigna Savi) in Africa

4 The need for increased efficiency of conversation
“Develop, where necessary, guidelines for the selection, establishment and management of protected areas or areas where special measures need to be taken to conserve biological diversity.” Article 8 - CBD (UNCED, 1992)

5 What is ‘gap analysis’? So called ‘Gap analysis’ was initially associated with Margules et al. as a conservation evaluation technique To identifies areas in which selected elements of biodiversity are represented then by comparison with protected areas identify under-represented areas or gaps (Margules, 1989) Largely applied to indigenous forests particularly on small islands rich in endemic species

6 Goal of Plant Genetic Conservation
“95% of all the alleles at a random locus occurring in the target population with a frequency greater than 0.05” Marshall and Brown (1975) Equates to approx. 50 sites x 100 plant collections or 5,000 individuals in a genetic reserve Post-CBD add “using a range of conservation techniques”, which takes account of complementary conservation

7 Has this goal been achieved?
FAO (1998)

8 Is ex situ / in situ conservation working effectively?
PGR ex situ NO, except for major crops! FAO figures for gene bank holdings show that for minor crops few species meet needs but some are over collected PGR in situ NO! Heywood review of genetic reserves approx 10 genetic reserves for all crops On-farm projects possibly project and all lack consistency of funding – no sustainability Traditional gap analysis techniques may be adapted to use in the PGR context

9 Gap Analysis Methodology
Burley (1988) identified four steps in traditional gap analysis: identify and classify biodiversity locate areas managed primarily for biodiversity identify biodiversity that is underrepresented in those managed areas, and set priorities for conservation action. Still applied to ecosystem conservation, can we adapt for plant genetic conservation

10 Adaptation of Gap Analysis for PGR Conservation
Not just dealing with ecosystem conservation in protected areas Conserving genetic as well as taxonomic diversity Complementary conservation, two strategies (in situ and ex situ) and a range of techniques for each Linking conservation to utilisation

11 PGR Gap Analysis Methodology
Essentially PGR gap analysis involves: Comparison of range of diversity with Conserved sample of that range of diversity The ‘analysis’ comes in the comparison Does the sample provide a efficient representation of the range of diversity? The diversity not represented in the sample is the gap!

12 PGR Gap Analysis Methodology
In the PGR context implies a series of steps: Step 1:Circumscription of target taxon and target area Step 2: Assessment of natural in situ diversity 2a - Taxonomic Diversity Assessment 2b - Genetic Diversity Assessment 2c - Ecogeographic Diversity Assessment 2d - Threat Assessment Step 3:Assessment of current conservation strategies 3a - In situ techniques 3b - Ex situ techniques Step 4: Setting priorities for conservation action 4a - In situ conservation priorities 4b - Ex situ conservation priorities

13 When to apply PGR GA? Once target taxon selected?
As part of ecogeographic study? Before application of conservation strategy? When reviewing conservation strategy?

14 Step 1:Circumscription of target taxon and target area
Defined by project commission for conservation action Breadth of target taxon Breadth of target area

15 Step 2: Assessment of natural in situ diversity – 2a Taxonomic Diversity
Need to select a classification List of accepted taxa Descriptive data Distributional data How to find the appropriate classification Specialist publications Taxon experts Various media searches (International Legume Database and Information Service ( or Species 2000 (

16 2a Taxonomic Diversity: Vigna
Classification of African Vigna Marchal et al. (1978) + subsequently described taxa Pasquet (2001) conception of V. unguiculata Tomooka et al. (2002) conception of subgenus Ceratotropis. 61 species and 56 subspecific taxa for Africa

17 2b - Genetic Diversity Assessment
Need to understand patterns of genetic diversity for target taxa Is it correlated with ecogeography or not?

18 2b - Genetic Diversity Assessment

19 Comparison of Genetic diversity with Ecogeography
UK study of UK native plant species: Beta vulgaris subsp. maritima (L.) Arcang., Brassica rapa L., Calluna vulgaris (L.) Hull, Chamaemelum nobile (L.) All. and Trifolium repens L. Correlated - Chamaemelum nobile, Calluna vulgaris, Brassica rapa No obvious correlation -Beta vulgaris subsp. maritima and Trifolium repens Possible association with introgression with crops In the absence of genetic diversity information, ecogeographic data provides the best approximation!

20 2b - Genetic Diversity Assessment
Too expensive to collate de novo Review what is available via a web search

21 2b - Genetic Diversity Assessment: Vigna
Entirely restricted to cowpea gene pool studies Eleven subspecies plus several varieties Pasquet (1993a, 1993b, 1997) Coulibaly et al. (2002) Is this situation typical?

22 2c - Ecogeographic Diversity Assessment
In the absence of genetic diversity data ecogeographic data provides the most appropriate proxy Established models for ecogeographic data collection, analysis and application, e.g. Maxted at al. (1995, etc.)

23 2c - Ecogeographic Diversity Assessment: Vigna
Based on 7,300 herbarium specimens and 1,912 germplasm accessions Herbarium specimens from 30 herbaria in Africa, Europe and North America Germplasm accessions from 4 gene banks (IITA, ILRI, CIAT and Jardin Botanique Nationale de Belgique) Basis of analysis

24 2c - Ecogeographic Diversity Assessment: Vigna
Density of collections in 200 km x 200 km grid cells

25 2c - Ecogeographic Diversity Assessment: Vigna
Observed geographic area of distribution calculated using the Circular Area statistic with a 50km radius (CA50)

26 2c - Ecogeographic Diversity Assessment: Vigna
Species richness per degree latitude

27 2c - Ecogeographic Diversity Assessment: Vigna
Species richness per 50m altitude class

28 2c - Ecogeographic Diversity Assessment: Vigna
Species richness of Vigna in 20 km x 20 km grid cells smoothed using inverse distance weighting and a window of 200 km radius

29 2c - Ecogeographic Diversity Assessment: Vigna
Absolute species richness based on herbarium collections only in 200 km x 200 km grid cells

30 2c - Ecogeographic Diversity Assessment: Vigna
Absolute species richness of germplasm collections only in 200 km x 200 km grid cells

31 2c - Ecogeographic Diversity Assessment: Vigna
Predicted distribution of species richness

32 2d - Threat Assessment Media reports IUCN categories
Target taxon specific Region or nation specific IUCN categories Need to understand is incomplete

33 IUCN Assessment for Vigna
Assessors Red List Criteria Version Categories Walter and Gillett (1998) Pre-1994 V. debanensis (Ethiopia) = Vulnerable V. dolomitica (Zaire) = Rare Golding (2002) 1994 Vigna comosa subsp. abercornensis (Zambia) = Vulnerable Maxted et al. (2005) 2001 6 Vigna = Critically Endangered 8 Vigna = Endangered 10 Vigna = Vulnerable 5 Vigna = Near Threatened 28 Vigna = Least Concern 4 Vigna = Data Deficient

34 Taxon Vulnerability Assessment
IUCN Red Listing is best assessment, but not always sufficient data Can approximate vulnerability to genetic diversity and even extinction using seven criteria: rarity distributional range gross representation in ex situ collections geographic coverage of ex situ collections coverage of ex situ collections utility extinction assessment Crude measure

35 Taxon Vulnerability Assessment Analysis
Rarity - estimated from the total number of herbarium specimens and gene bank accessions of each taxon Distributional range – calculated from a radius around each collecting locality and then by merging the resulting circles calculates the total distributional area Gross representation in ex situ collections - numbers of gene bank accessions should be approximately 10% of the number of herbarium specimens, any species with a lower proportion are vulnerable

36 Taxon Vulnerability Assessment Analysis
Geographic coverage of ex situ collections - compares the geographic distribution of ex situ conserved accessions with the entire range of geographic distribution Intra-species coverage of ex situ collections – compares ex situ sampling with actual distribution Utility – Within the genetic resource context it is entirely viable to include a use factor

37 Taxon Vulnerability Assessment Analysis
Extinction assessment - Solow’s equation (Solow, 1993) as proposed by Burgman et al. (1995), which uses a combination Collection timing Frequency Specimen numbers Each one generates a numeric score of 0 – 10 Scores are calculated for taxa

38 Taxon Vulnerability Assessment Analysis: Vigna
Species Rarity Distrib-ution Ex situ holdings Ex situ coverage Taxon coverage Use Taxon extinction TVA score V. adenantha 5 2.5 9 8 4 4.6 V. ambacensis 1 2 10 2.6 V. angivensis 6 5.3 V. antunesii 3 4.1 V. benuensis 7 7.5 5.1 V. bequaertii V. bosseri 7.0 V. comosa 3.9 V. desmodioides

39 Step 3:Assessment of current conservation strategies
In situ Genetic reserve of CWR On-farm of landraces Ex situ Seed bank of germplasm Other techniques ?

40 3a - In situ techniques / reserve
No active genetic reserves for Vigna species Passive conservation which is coincident with existing protected area Likely to establish reserve in existing protected area

41 MAB Protected Areas in Africa

42 3a - In situ techniques / reserve
MAB not only protected areas, many other see IUCN listing of National Parks and Protected Areas Few countries have adequate represented of protected areas like Kenya, Guinea and South Africa 54% of wild species Vigna are predicted to have populations present in at least one protected area In reality, the number and ecogeographic diversity of African Vigna species makes in situ conservation the only practical conservation option for adequate conservation of the broadest gene pool Need to match distribution to existing protected areas

43 3a - In situ techniques / on-farm
Find by literature / media / internet review Cowpea (V. unguiculata) is included in IPGRI’s current on-farm conservation project in Burkina Faso (Jarvis and Ndungứ-Skilton, 2000) Shea project in Uganda includes Bambara groundnut (Vigna subterranea) Community Technology Development Trust project in Zimbabwe includes V. subterranea and V. unguiculata (Odero, 2001) But no systematic on-farm conservation of Vigna in Africa

44 3b - Ex situ techniques Review of gene bank holdings, SINGER, EURISCO, but little help for Africa Species IITA NBGB USDA Other V. unguiculata subsp. unguiculata 14,887 15 4,399 - V. unguiculata wild 553 188 244 51 V. subterranea 2032 64 Other Vigna taxa 1216 304 50 111

45 3b - Ex situ techniques Regression of Vigna species against herbarium specimens and gene bank accessions from each country Results indicate Botswana, Namibia, South Africa and Swaziland were over-collected, while Angola, Burundi, Cameroon, Democratic Republic of the Congo, Djibouti, Nigeria, Tanzania and Zambia remain under-collected.

46 Step 4: Setting priorities for conservation action
Having provided The best possible picture of in situ natural diversity A review of current in situ and ex situ conservation actions Comparison of the two identifies ‘Gaps’

47 4a - In situ conservation priorities
Highest concentration of taxa in three hotspots of Vigna species richness around the Great Lakes the southern tip of Lake Tanganyika the Cameroon Highlands But crude species richness can give a false impression

48 4a - In situ conservation priorities
Complementarity analysis

49 4a - In situ conservation priorities
Country Protected area name Type of protected area IUCN protected area categories Location Area (km2) Zambia Lusenga Plain National Park II 9°23'S/ 29°13'E 88,000 Mweru-Wantipa 8°44'S/ 29°38'E 313,400 Nsumbu 8°47'S/ 30°30'E 206,300 Tanzania Uwanda Game Reserve IV 8°32'S/ 32°08'E 500,000 Katavi 6°53'S/ 31°10'E 225,300 Mahale Mountain 6°10'S/ 29°50'E 157,700

50 4a - In situ conservation priorities
Areas of Africa where in situ Vigna conservation action is required

51 4a - In situ conservation priorities
Existing protected areas where in situ Vigna reserves could be established

52 4a - In situ conservation priorities
With 23 of the 61 African Vigna species being utilised and many of the species have multiple uses within subsistence agriculture, on-farm conservation should be a priority! Inevitably it will focus initially on the two most widely cultivated grain legume species, V. subterranea and V. unguiculata But a more geographically systematic approach that considers full taxonomic breadth is required

53 4b - Ex situ conservation priorities
Country based priorities Highest priority: Cameroon, Democratic Republic of the Congo, Guinea Bissau, Nigeria and Zambia Other priorities: Angola, Benin, Burundi, Cameroon, Cote d’Ivoire, the Democratic Republic of the Congo, Djibouti, Eritrea, The Gambia, Guinea, Guinea Bissau, Liberia, Madagascar, Mozambique, Nigeria, Rwanda, Sierra Leone, Somalia, Tanzania and Zambia.

54 4b - Ex situ conservation priorities
Priority Rating Vigna taxa High priority V. dolomitica, V. haumaniana var. pedunculata, V. monantha, V. nuda, V. richardsiae, V. somaliensis, V. stenophylla, V. subterranea var. spontanea, V. unguiculata subsp. unguiculata var. spontanea, V. unguiculata subsp. aduensis, V. unguiculata subsp. baoulensis, V. unguiculata subsp. burundiensis, V. vexillata var. dolichonema and V. virescens. Medium Priority V. bequaertii, V. comosa subsp. comosa var. lebrunii, V. desmodioides, V. haumaniana, V. haumaniana var. haumaniana, V. hosei, V. laurentii, V. multinervis, V. parkeri subsp. parkeri, V. phoenix, V. procera. Low V. adenantha, V. angivensis, V. antunesii, V. bosseri, V. comosa, V. comosa subsp. abercornensis, V. fischeri, V. frutescens, V. frutescens subsp. kotschyi, V. gazensis, V. juncea, V. juncea var. corbyi, V. juruana, V. keraudrenii, V. kokii, V. longifolia, V. longissima, V. macrorhyncha, V. membranacea subsp. macrodon, V. microsperma, V. monophylla, V. mudenia, V. parkeri, V. praecox, V. pygmaea, V. schimperi, V. triphylla and V. venulosa.

55 Conclusion Proposed Methodology
Step 1:Circumscription of target taxon and target area Step 2: Assessment of natural in situ diversity 2a - Taxonomic Diversity Assessment 2b - Genetic Diversity Assessment 2c - Ecogeographic Diversity Assessment 2d - Threat Assessment Step 3:Assessment of current conservation strategies 3a - In situ techniques 3b - Ex situ techniques Step 4: Setting priorities for conservation action 4a - In situ conservation priorities 4b - Ex situ conservation priorities Need refinement but could be a working basis for PGR GA?