Module 3
Seed supply chain

This Module allows students to consider how different parts of the germplasm supply chain affect genetic diversity in species. The two case studies present
contrasting situations. The Araucaria study focuses on restoration efforts for an endangered species in a relatively well resourced country, whereas the study
of nurseries in East Africa emphasizes the establishment of both native and exotic species on the land of resource-poor farmers. The module explores forest
genetic resources aspects such as:

  • Reproductive materials – source, collection and distribution
  •  Genetic processes associated with small populations – bottleneck, increased genetic drift, increased inbreeding and consequently homozygosity
  •  Effective population size compared to census size
  • Sexual systems – dioecy, hermaphrodite
  •  Self-incompatibility mechanisms



Downloadable materials
Module 3 - introductory notes for teachers  [ PDF  (957 KB) |]
Case Study 3.1 Genetic bottlenecks in the restoration of Araucaria nemorosa 
Case Study 3.2 Tree planting on farms in East Africa: how to ensure genetic diversity?