Genetic diversity and variety composition of cassava on smallscale farms in Uganda: an interdisciplinary study using genetic markers and farmer interviews
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Date
2007
Authors
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Journal ISSN
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Publisher
Genetica
Abstract
Cassava is a tropical crop and grown for its
tuberous starchy roots. In Africa it is mainly cultivated
by small-scale farmers who observe, select and name
their cassava varieties based on morphology, food,
social and economic interest. Here we have used an
interdisciplinary approach involving farmer interviews,
genetic markers and morphological descriptors to
study the composition of cassava varieties on smallscale
farms in 11 villages located in three districts in
Uganda, the genetic structure within and between
these varieties and their morphology. The composition
of local, newly introduced and improved varieties differed
widely between villages and districts. The
Ugandan farmers in our study seemed to adopt improved
varieties to a greater extent when there was a
nearby market, prevalence of disease epidemics and
good extension service. We found considerable genetic
variation both within and between cassava varieties
though the variation was larger between varieties.
However, most local and improved varieties showed
predominating genotypes at many loci. Accessions of
commonly grown varieties meeting farmers’ preferences
could therefore be selected and implemented in
future breeding programmes involving development,
dissemination and adoption. The like-named varieties
in different villages were genetically similar, demonstrating
farmers’ ability to differentiate and maintain
the same variety over large areas. However, some
varieties with different names in different villages
showed both genetic and morphological similarity,
suggesting that farmers may rename plants when they
are introduced into their fields. The large differences
found in variety and genetic composition between villages
and districts in Uganda may be a result of the
diverse needs and growing conditions characteristic for
traditional farming system. This suggests that efforts to
conserve and increase the genetic diversity in farmers’
fields will require policies tailored to each area
Description
Keywords
Cassava varieties, Crop evolution, Farmers’ management, Genetic differentiation, Manihot esculenta, Morphological variation, Small-scale farmers, SSR markers, Traditional farming system
Citation
Balyejusa Kizito, E., Chiwona-Karltun, L., Egwang, T., Fregene, M., & Westerbergh, A. (2007). Genetic diversity and variety composition of cassava on small-scale farms in Uganda: an interdisciplinary study using genetic markers and farmer interviews. Genetica, 130(3), 301-318. DOI 10.1007/s10709-006-9107-4