Crop Genetic Resource Erosion:

1
Crop Genetic Resource Erosion

• Conservation through Traditional Agroecosystems
  and Neo-land Races for the Future.

Matthew Leon December 9, 2003
2
Questions

• What patterns of biodiversity exist and how are
  they connected to agriculture?
• Is biodiversity linked with cultural diversity?
• How is biodiversity erosion affecting
  agriculture?
• What are our best options for conserving our
  genetic resources?
• What should future breeding strategies look like?

3
Outline

• Vavilov centers, origins of agriculture
• Relations between cultural and genetic diversity
• Cultural and genetic erosion
• Land races vs. High Yielding Variety (HYV)
  hybrids
• Ex situ and in situ conservation strategies
• Developing neo land races

4
Patterns in Biodiversity

• Origins of nearly all major crops.
• Gene rich bioregions located in certain tropical
  areas.
• Coined by N.I. Vavilov Russian botanist of the
  20s

Following years of exploration, N.I. Vavilov
concluded that a combination of varied
topography, climate and cultivation methods
resulted in almost all major crops originating on
less than one-quarter of earths arable land.
(Mooney 1979, p.3)
5
Vavilov Centers
Source Mooney 1979 p.4
6
Cultural and genetic diversity

• Genetic diversity linked with biodiversity
• Biodiversity in ecosystems give each location its
  own unique form.
• Cultures are developed in reaction to their
  ecosystem.
• Cultural diversity is linked to ecosystem
  diversity which is related to biodiversity and
  genetic diversity.

7
Vavilov centers coincide with developing countries

• Culture, genetic and biodiversity in jeopardy
• Development coincides with the politics of
  disappearance. (Shiva, 1993 p.12)
• Western (dominant) knowledge system negating the
  existence of other local knowledge systems
• If it still appears classified as primitive or
  unscientific

8
DominantKnowledgeSystemDisrupts
IntegrationsBetween Systems
9
Erosion of BiodiversityPrimary causes

• Habitat destruction mainly due to internationally
  financed development projects dams and clear
  cuts
• Replacement with monocultures of forestry and
  agriculture

10
Vulnerability of Monocultures

• Monocultures vulnerable to disease and pests
  mainly due to low species and genetic diversity
• 1846 Irish potato famine
• 1970 southern corn leaf blight
• 1968-77 Indonesian rice disaster

11
Internalvs.ExternalInputs
Source Shiva, 93 p.76
12
Decline of species used in food production

• Traditional indigenous culturesmore than 1500
  wild species and 500 vegetable crop species
• Modern agriculture 20 species in major crop
  production, 80 by small market production, and
  200 in home gardens
• Our history is one of declining food variety as
  more people are fed by fewer plant species

13
Disappearing solutions

• Locally adapted cultivated plants referred to as
  land races, folk varieties, heirlooms, etc.
• Land races used to interbreed with modern crop
  cultivars to deal with pests and diseases
• Land races disappearing due to biodiversity
  erosion
• With them the ability to deal with problems
  monocultures bring about

14
HYV hybrids vs. Land races

• Low genetic diversity
• High dependence on chemical inputs (Palmer
  suggests the term High Response Varieties or HRV)
• Not well adapted to low quality soil conditions

• High genetic diversity
• No dependence on chemical inputs
• Highly adapted to local microclimate and soils

15
Chemical Dependence ofHRV Seeds
16
Conservation strategies

• Ex situ seed banks isolated from origin
• seed cryogenically frozen, isolated garden plot
  or in petri dish
• In situ seed grown out annually in origin

17
Ex situ pros and cons

• Pros
• Long shelf life
• Easily accessible for first world breeding
  programs

• Cons
• Low number of species stored
• Lack of representation of crop relatives and wild
  plants
• Freezes evolutionary process
• Removed from cultural context

18
In situ

• Pros
• Crop and weedy relatives and wild plants all
  preserved
• Evolutionary process allowed
• Culture local knowledge preserved

• Cons
• Not very accessible to first world breeding
  programs
• Arguably unstable due to development and erosion
  affiliated with it

19
Combination of ex and in situ best option

• Strengths of one can support the weaknesses of
  the other

20
Developing new land races

• Synthesize traditional seed saving techniques
  into modern sustainable agriculture
• Increase genetic diversity through open
  pollinated techniques
• Developed locally so adaptations exist for each
  locale
• Adaptations to future environmental conditions
  will continue