1. Cultivated genetic diversity and farmers’ knowledge –
keys to cassava breeding
1Department of Plant Biology and Forest Genetics, Uppsala BioCenter, Swedish University of
Agricultural Sciences and Linnean Center for Plant Biology, Uppsala, Sweden
2Plant Resources Center, Vietnam Academy of Agricultural Sciences, Hanoi, Vietnam
Anna Westerbergh1, Hoang Thi Nga2, Per-Olof Lundquist1, Vu Linh Chi2

2. Cassava diversity and farmers’ knowledge
Pre-breeding
Identification of genotypes/plants
with desirable traits and genes
controlling these traits
in wild crop relatives and
local farmers’ varieties

3. Cyanogenic glycosides
Bitter Sweet
Cassava diversity and farmers’ knowledgeCyanogenic glycosides
Bitter Sweet
wild cassava

4. Pre-breeding
Breeding
Dissemination to farmers
Adoption by farmer - production
Licensing and release of improved varietiey
Time
Identification of plants with desirable traits
and genes controlling these traits
I. Crossing of selected plants
ll. Selection of progenies with desirable traits
combining trait evaluation and genetic markers
From ”wild” plant to a cultivated crop
?
Consumption, marketing

5. Cassava diversity and farmers’ knowledge
• But will these new improved cultivars be adopted by the
farmers?
• Are there other characteristics/traits and varieties
important for the farmers?

6. Cassava diversity and farmers’ knowledge
Interdiciplinary approach
Farmer interviews
Field observations
• name of cultivated varieties
• origin
• morphological description
• primary use
• desirable traits
• cultivation practices
Molecular markers – genetic bar code – genetic diversity

7. Cassava diversity and farmers’ knowledge
..... for comparative studies
Sắn xanh
local
variety
Sắn cao sản
improved
Sắn lá tre
improved
Sắn trắng
improved
Less genetic diversity within fields
Varieties in separate plots
Majority of improved varieties
Description – leaf, stem, root morphology & taste
Local – sweet
Improved – bitter
Constraints – climate, NOT diseases
Compared to findings in Uganda, the
cassava in Vietnam had:

8. Cassava diversity and farmers’ knowledge
Utilization and processing of bitter and sweet varieties

9. Cassava diversity and farmers’ knowledge
Colonization and diversity of arbuscular mycorrhiza in cassava roots
Glomeromycetes

10. Farmer-researcher collaboration
in pre-breeding and cassava improvement

11. Thanks to
Colleagues at
Plant Resource Center and
Vietnam Academy of Forest Sciences Forest Hanoi,Vietnam
Med Biotech Laboratories , Kampala, Uganda
International Center of Tropical Agriculture (CIAT), Cali, Colombia
SLU
Funders
UD (Swedish Ministry of Forein Affairs)
Formas (Swedish Research Council for Environment, Agricultural Sciences
and Spatial Planning)
Sida (Swedish Agency for Development Cooperation)
......and
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