Meta-transcriptomic identification of groundnut RNA viruses in western Kenya and the novel detection of groundnut as a host for Cauliflower mosaic virus.

BACKGROUND: Groundnut (Arachis hypogaea L.) is the 13th most important global crop grown throughout the tropical and subtropical regions of the world. One of the major constraints to groundnut production is viruses, which are also the most economically important and most abundant pathogens among cultivated legumes. Only a few studies have reported the characterization of RNA viruses in cultivated groundnuts in western Kenya, most of which deployed classical methods of detecting known viruses. METHODS: We sampled twenty-one symptomatic and three asymptomatic groundnut leaf samples from farmers' fields in western Kenya. Total RNA was extracted from the samples followed by First-strand cDNA synthesis and sequencing on the Illumina HiSeq 2500 platform. After removing host and rRNA sequences, high-quality viral RNA sequences were de novo assembled and viral genomes annotated using the publicly available NCBI virus database. Multiple sequence alignment and phylogenetic analysis were done using MEGA X. RESULTS: Bioinformatics analyses using as low as ∼3.5 million reads yielded complete and partial genomes for Cauliflower mosaic virus (CaMV), Cowpea polerovirus 2 (CPPV2), Groundnut rosette assistor virus (GRAV), Groundnut rosette virus (GRV), Groundnut rosette virus satellite RNA (satRNA) and Peanut mottle virus (PeMoV) falling within the species demarcation criteria. This is the first report of CaMV and the second report of CPPV2 on groundnut hosts in the world. Confirmation of the detected viruses was further verified through phylogenetic analyses alongside reported publicly available highly similar viruses. PeMoV was the only seed-borne virus reported. CONCLUSION: Our findings demonstrate the power of Next Generation Sequencing in the discovery and identification of novel viruses in groundnuts. The detection of the new viruses indicates the complexity of virus diseases in groundnuts and would require more focus in future studies to establish the effect of the viruses as sole or mixed infections on the crop. The detection of PeMoV with potential origin from Malawi indicates the importance of seed certification and cross-boundary seed health testing.

An ethnobotanical study of medicinal plants used by the Nandi people in Kenya.

ETHNOPHARMACOLOGICAL RELEVANCE: The study of local knowledge about natural resources is becoming increasingly important in defining strategies and actions for conservation or recuperation of residual forests. AIMS OF THE STUDY: This study therefore sought to collect information from local populations concerning the use of Nandi Forest medicinal plants; verify the sources of medicinal plants used and determine the relative importance of the species surveyed. MATERIALS AND METHODS: Data was obtained using semi-structured forms to record the interviewee's personal information and topics related to the medicinal use of specific plants. A total of 40 medicinal plants used locally for the treatment and/or control of human ailments were collected through interviews conducted with selected traditional doctors and professional healers. RESULTS: This study demonstrated that local people tend to agree with each other in terms of the plants use and that leaf material form the major component of plant parts exploited. The other harvested materials consist of stem bark, the roots and the whole plant, though at a lower intensity for making liquid concoctions from different plants. Majority of the remedies were prepared from a single species. In most cases, the mode of administration was oral. In the forest, some of the plants collected were scarce. This scarcity was attributed to indiscriminate logging, overexploitation, poor harvesting methods and current agricultural trends. CONCLUSION: Conservation procedures and creation of awareness were identified as the main remedies to the current situation.