Effects of seed size and nursery media on the germination and seedling growth of Plukenetia conophora

Research on the effects of seed size, soil-based and soilless media to determine the best condition for increased seedling production of African walnut was carried out at the green house of Department of Crop Science and Technology, Federal University of Technology, Owerri. Seed size was categorized into 10.23 to 10.31g (for large seeds) and below 10.23g (for small seeds). Soil-based nursery medium was sawdust mixed with topsoil volume by volume (v/v) 1:1, while soilless was sawdust alone. The experiment was a 2×3 factorial in a complete randomized design with 6 replications. Data were collected on number of days to emergence, plant height at 4, 8, and 12 weeks after planting (WAP), and number of leaves at 4, 8, and 12 WAP. Data collected were tested with analysis of variance (ANOVA), and treatment means were separated with Fishers least significant difference at 5% level of probability. Result showed that large seeds planted on soil-based media performed best in all the assessed traits. The inference is that high quality seedlings of African walnut can be produced by planting large seeds in soil-based media

Molecular Genetic Diversity in Bambara groundnut [Vigna subterranea (L.) Verdc] Assessed by Microsatellite Markers

Bambara groundnut is a valuable leguminous crop with many landraces. A study was carried out to establish genetic diversity and phylogenetic relationship, among 33 Bambara groundnut accessions based on simple sequence repeat (SSR) markers. The nine microsatellite markers amplified a total of 27 alleles with a mean of 6.00 alleles per locus. Marker P 36 had the highest number of polymorphic bands while makers P131 and P68 were monomorphic. Genetic distance among the accessions based on Jaccard’s similarity coefficient ranged from 0.84 to 1.00. Cluster analysis resolved the accessions into five major groups with subgroups. Each group had a combination of distinct accessions from different geographical origin. A substantial level of intra-accession polymorphism was obtained among the evaluated collection of Bambara groundnut. The significant genetic diversity observed can support the selection of appropriate parental genotypes for the improvement of Bambara groundnut through various breeding programmes