Characterization of Virus-Free Sweet Potato (Ipomea Hatata (L) Lam) Landraces Using Morphological and SSR Markers in East Kamagak Location-Homabay County
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Date
2014
Authors
onyango, Rosally Anyango
Journal Title
Journal ISSN
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Publisher
Kenyatta University
Abstract
Sweet potato is one of the most important crops for food security and income
generation in Kenya. The crop is increasing in importance as adverse climate
changes limit crop production in many areas. Understanding the genetic diversity of
germplasm of crop species is ofimportance for its rational management and use.
Identification of the sweet potato landraces is paramount in addressing food security
not only in the study region but elsewhere in the country. Morphological
characterization of the accessions facilitates the identification of duplicates and
unique traits which is important in the future improvement of the crop having the
desired characteristics. The study aimed at identifying sweet potato landraces that
have high quality and high consumer acceptance in the area in East Kamagak
location of Rachuonyo District, Homabay County .The experiment started with
survey and germplasm collection aided by use of questionnaire. The collected
germplasm was virus indexed using visual scoring, serological and molecular
detection. Six sweet potato landraces from East Kamagak along with six released
varieties from Kenya Agricultural Research Institute Njoro were used for the study.
The accessions were planted using Randomized Complete Block Design. Planting
was done in two sites (Sino and Kachieng). Eighteen qualitative (ground cover, leaf
shape, tuber colour.) and Eight quantitative characters (leaf length, vine inter-node
length,vineweight, yield of tuber.) were scored one month after planting upto
harvesting using the sweet potato descriptors oflnternational Potato Centre (CIP).
Harvesting was done at 6 months after planting and tubers dried at 60°C to deterrn ine
the dry matter content.The accessions exhibited high morphological diversity in
aerial and rootcharacteristics. Analysis of variance showed that out of 24 characters
evaluated for morphological characterization, 17 characters were significantly
different at p<O.OS. Predominant vine color and mature leaf color did notshow any
significant difference. The dendrogram obtained using morphologicalcharacteristics,
separated the accessions into two major clusters with Euclidean distancesranging
from 0.00 to 6.66 in Kachieng and 0.00 to 8.11 in Sino. Accessions Rachar, Nyathi
odiewo and Nyakowino which are local land races showed high yield alongside the
recommended commercial check accession Nyawo, SpkO 13 and Mugande.
Nyakowino is also rich in beta carotene content.SSR marker I8-ClP 13 and IB-R 19
were able to detect polymorphism in the germplasm under study
Description
Department of Agricultural Sciences and Technology, 107p. 2014