Genotypic Characterization of Catha edulis in Mt. Kenya Region, Kenya

Abstract

Khat (Catha edulis Vahl) is a plant that is habitually ingested for its euphoric and stimulatory effects. This study aimed at evaluating genetic diversity of selected khat cultivars grown in Embu and Meru Counties Mt Kenya region. This will ensure that genetic resources are preserved and secured for future so that benefits from such plants continue to flow. DNA extraction was done using CTAB method and genetic diversity determined using 5 SSR markers. The number of alleles per locus ranged from 2 to 4 with an average of 2.4 across the 5 markers used. Gene diversity per locus ranged from 0.2296 (CE50) to 0.3344 (CE64) with an average of 0.2883 and Polymorphic Information Content (PIC) ranged from 0.2024 (CE50) to 0.2878 (CE37) with an average of 0.2475. A two dimensional scatter plot was generated and the two PCoA axis accounted for 43.33 and 28.19% of genetic variation. The AMOVA indicated intra-population variation of 93% while inter-population variation was 7%. The unweighted neighbour joining tree clustered khat cultivars into three major clusters and subsequent sub-clusters. This study revealed that there is a considerable level of genetic diversity among the Mt. Kenya khat cultivars. This was indicated by the alleles observed and clusters generated.