Morphological Characterisation and Proximate Analysis of Selected Ugandan Sweetpotato (Ipomoea Batatas L.) Varieties for Food and Feed Use
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Date
2016-06
Authors
Mbithe, Muinde Jane
Journal Title
Journal ISSN
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Publisher
Kenyatta University
Abstract
Sweet potato Ipomoea batatas L. (Lam.) is a symbol in the fight for a global
nutrition plan that can save millions of children and help build a healthier and
more productive future. It is a smallholder crop tolerant to a wide range of edaphic
and climatic conditions and grown with limited inputs. Consequently, it has been
relied on as a source of calories since its vines and/or storage roots can be used for
direct human consumption, as well as providing inexpensive, protein-rich fodder
for animals. However, characterisation of sweet potato varieties with optimal
morphological features suitable for both food and feed has not been done. A
population of 10,000 first filial generation (Fl) sweet potato lines derived from
seeds was generated through polycross crossing design in Uganda using 24
parents. Preliminary evaluation for the suitability of dual use of the F I 's led to
selection of 11 varieties which were the basis of this study. This study thus sought
to morphologically characterise selected Ugandan sweet potato varieties to identify
those with superior characteristics suitable for food and feed purposes. In the early
screening stages, plants were raised from seeds after scarification. Germination of
the seedlings was done in special trays. A selection of seedlings possessing single
leaf lobes was done, after which they entered observation yield trials (OT).This
was done in order to discard those that clearly did not meet the lowest acceptable
gross morphological descriptors. Morphological and nutritional data were taken at
90 and 180 days, respectively. The data were subjected to analysis of variance in
order to find out if significant differences exist between the varieties based on
morphological and nutritional components. Cluster analysis was done using
Minitab version 17 software. There were significant differences (p~O.05) in most
of the vine characters, however vine internode length and vine tip pubescence were
not significantly different (p2:0.05). Among the 11 varieties, there were
significant differences in all the leaf and root characters analysed. Proximate
analysis showed that there were significant differences (p~O.05) among the 11
varieties in all the root parameters evaluated (on a dry matter basis), and dry matter
was above 90% in all 11 varieties. Among the 11 varieties, vine characteristics
(based on dry matter), including ash content, dry matter, organic matter, nitrogen,
in vitro organic matter digestibility, crude protein, and metabolisable energy were
all significantly different (p~O.05) among the varieties. However, there were no
significant differences in neutral detergent fibre, acid detergent fibre and acid
detergent lignin (p~O.05). This study established that Naspot I is a high dual
variety, Rwabuganda and New Kawogo are low dual varieties and BNDI45L,
Shock, Dimbuka bukulula, Kigabali, Magabari, Naspot II, Kyabafuruki and
Kyebandula are forage varieties.
Description
A Thesis Submitted in Partial Fulfilment of the Requirements for the Award of the Degree of Masters of Science (Biotechnology) in the School of Pure and Applied Sciences of Kenyatta University