Muturi, JGichuki, CWaceke, J.WRuno, Steven2021-06-092021-06-092003Muturi, J., Gichuki, C., Waceke, J. W., & Runo, S. M. (2003). Use of isozyme phenotypes to characterise the major root knot nematodes (Meloidogyne spp.) parasitising indigenous leafy vegetables in Kisii. In Transforming Agriculture for Improved Livelihoods through Agricultural Product Value Chains: the Proceedings of the 12th KARI Biennial Scientific Conference. Nairobi, Kenya: Kenya Agricultural Research Institute (pp. 605-12).http://ir-library.ku.ac.ke/handle/123456789/22297Research ArticleRoot knot nematodes belonging to the genus Meloidogyne are the most economically important group of plant parasitic nematodes. Their worldwide distribution, extensive host range and interaction with other plant pathogens in disease complexes rank them among the top plant parasitic pathogens affecting the worlds food supply. Yearly crop losses of 5% have been reported worldwide. The damage inflicted in certain regions of developing countries exceeds this level. To improve the identification of Meloidogyne populations , a rapid technique should be developed which is easy to apply. The objective of this study was to determine the occurrence, distribution and identity of root knot nematodes (RKN) affecting Indigenous leafy vegetables (ILVs) in Kisii District. A total of 200 samples of (Solanum nigrum, Amaranthus hybridus and Cleome gynandra) affected by RKN were collected from two divisions, Sameta and Kilgoris. Previous studies on the diversity of Meloidogyne spp. have focused on morphology (perineal patterns, stylet structure, body length), and the response of the populations to differential host test. Morphological differences may be difficult to observe making identification of nematodes by these procedures difficult. Enzyme phenotype, using esterases (Est) and malate dehydrogenase (Mdh), can be used to characterize Meloidogyne spp. populations from different ILVs using a simplified technique for routine analyses. Soluble proteins from macerates of individual females were separated by vertical electrophoresis on 0.7 mm-thick-polyacrylamide gels (12 %). After electrophoresis gels were stained for enzymatic activity in a Petri dish at 37º C with different staining solution. The species identity of forty RKN affecting ILVs in Kisii was reviewed using isoenzyme analysis. Meloidogyne javanica had the phenotype J3 while M. arenaria had phenotype A2. Species specific phenotype I1 was 50%, J3 was detected in 25% of the samples from Kisii while phenotype A2 was found in 25 %. Mdh and Estarase phenotypes are species specific and are used for identification of RKNenPolyacrylamide gel electrophoresis (PAGE)Meloidogyne sppArticle