Guava (Psidium guajava L) is native to South America and exists as both wild and cultivated. Guava has been used as a source of food and raw materials for pharmaceuticals. The aim of this study was to determine bioactivity of methanol and water extracts from root and leaves of Kenyan guava landraces against selected pathogenic bacteria. Study samples were collected from Western and South Coast of Kenya. One hundred grams of leaf and root ground powders were used for sequential extraction using methanol and water. Extracts were evaporated and 0.2gms dissolved using the extraction solvent and tested against gram positive (Staphylococcus aureus, Bacillus subtilis) and negative bacteria (Escherichia coli). Data on inhibition zone was taken in mm and analyzed at 95% confidence interval. Extracts from Western region had significant inhibition compared to Coastal region. The two regions have different climatic conditions that result in these plants having different compounds even though they are the same species. Roots had higher inhibition compared to the leaves as they contain high levels of tannins compared to leaves. Water as an extracting solvent had higher inhibition than methanol as it is more polar and it absorbs more bioactive compounds. S. aureus was most inhibited followed by E. coli and B. subtilis respectively. There was no significant difference between the gram positive and negative bacteria. Remarkably, some methanol and water root extracts had significant inhibition against bacteria when compared to some commercial antibiotics used. Results of this study indicate that Kenyan guava roots from Western Kenya extracted with methanol and water have a potential to be used as a source of active compounds in treatment of gram positive and gram negative bacteria pathogens.

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Tamarind is native to tropical parts of Africa and Asia. It shows considerable phenotypic variation in morphological and horticultural traits that can be utilized in its genetic improvement. In Kenya, there exists a wide range of tamarind germplasm that has not been characterized. Initial characterization is based on morphological descriptors. The objective of this study is to evaluate morphological diversity of tamarind germplasm from Eastern parts of Kenya. Tamarind germplasms were collected from Kitui, Mwingi, Masinga, Embu and Kibwezi and then characterized using morphological descriptors based on seed, fruit and stem. Morphological characters were recorded and data from eighty-nine accessions were submitted to principal component and hierarchic ascendant analysis (HAC) and Euclidian average distance. Accessions from Kibwezi, Embu and Kitui showed the greatest diversity while accessions from Masinga and Mwingi had the least diversity. Trunk diameter at ground, pod weight, number of seeds/pod, height to the first branch and pod width showed greatest variation in principal component analysis. High morphological diversity obtained in these regions can be used to initiate new breeding and conservation programmes in tamarind for improved fruit and tree crop.