Sweetpotato cultivars with improved storage root quality
Partners:
International Potato Center, Uganda and Kenya
Sugarcane Research Institute (Kibaha) Tanzania
HortiTengeru, Arusha, Tanzania
Sokoine University of Agriculture, Tanzania
Namulongwe Agriculture Research Organisation, Uganda
Agricultural and Animal Production Research Institute
(SAARI), Uganda
Problem:
Breeding initiatives for sweetpotato are at an early stage compared to other staple crops. Given the enormous genetic diversity of sweetpotato worldwide, and that breeding programmes of sweetpotato are relatively new, crop improvements are expected to be rapid. This cluster of outputs arises from projects undertaken to examine germplasm available in East Africa, the potential for breeding for specific post-harvest/quality traits, and to identify strategies to facilitate effective cultivar selection.
Achievements:
Many of the project activities were focused towards understanding the physiological basis for differences among germplasm. The resulting outputs can feed into breeding strategies at two levels: use of molecular markers (appropriate for international breeding programmes such as that at CIP); identification of selection techniques suitable for National Programmes with more limited facilities. Results from the studies
- Identification of farmer, trader
and consumer criteria for sweetpotato cultivars
in east Africa and strategies to incorporate
them into selection protocols during breeding.
- Methods developed for the use of
consumer tests and trained taste panels to assess
sensory characteristics of sweetpotatoes.
- Breeding strategies to select for
extension of shelf-life. Sweetpotato cultivars
in East Africa have a wide range of shelf-life. We
established that a key factor affecting shelf-life
is the efficiency by which storage roots heal wounds
at low humidity. Unfortunately high wound-healing
efficiency is associated with lower dry matter
content, although we do not know if this is a causative
relationship. Simple strategies, appropriate
for use by national programmes, to assess wound-healing
efficiency using tissue staining methods, or weight
loss measurements have been developed.
- Increased understanding of the
effect of root shape on susceptibility to damage
during handling.
- Increased understanding of cultivar
characteristics affecting long-term storability.
- Strategies to select for cultivars with canopy and rooting structures that confer reduced susceptibility to field infestation by insects, especially Cylas spp., including methods to assess appropriate root structures, and design of field trials with appropriate levels of insect pressure for efficient cultivar selection.
Further Information
Dr Debbie Rees, Plant Physiologist
d.rees@gre.ac.uk Work +44 (0)1634 88 3522 Fax +44 (0)1634 88 3386
