onyango, Rosally Anyango2015-08-102015-08-102014http://ir-library.ku.ac.ke/handle/123456789/13404Department of Agricultural Sciences and Technology, 107p. 2014Sweet 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 studyenThesis