Cross-amplification and characterization of polymorphic microsatellite markers from Acacia (Senegalia) mellifera and Acacia brevispica to Acacia senegal (L.) Willd.

Seven polymorphic microsatellite markers isolated from Acacia brevispica and Acacia mellifera were successfully cross-amplified in Acacia senegal. The loci were surveyed for polymorphism using 30 samples. Allelic diversity ranged from 4 (Ame02, Ab06 and Ab18) to 13 (Ab26) per locus. The expected heterozygosity (HE) ranged from 0.543 (Ame02) to 0.868 (Ab26) while observed heterozygosity (HO) ranged from 0.516 (Ame05) to 0.800 (Ame03). Cross amplification of these loci represents a potential source of co-dominant marker and will be useful in the study of genetic diversity, structure, gene flow and breeding systems of this important Acacia species

Genetic diversity and population structure of the African catfish, <i>Clarias gariepinus</i> (Burchell, 1822) in Kenya: implication for conservation and aquaculture

African catfish, Clarias gariepinus, is an important species in aquaculture and fisheries in Kenya. Mitochondrial D-loop control region was used to determine genetic variation and population structure in samples of C. gariepinus from 10 sites including five natural populations (Lakes Victoria (LVG), Kanyaboli (LKG), Turkana (LTA), Baringo (LBA) and Jipe (LJP), and five farms (Sangoro Aquaculture Center (SAN), Sagana Aquaculture Centre (SAG), University of Eldoret Fish Farm (UoE), Kibos Fish Farm (KIB), and Wakhungu Fish Farm (WKU)) in Kenya. Similarly, samples from eight localities (four natural populations: LVG/LKG, LTA, LBA, and four farmed: SAN, SAG, KIB, UoE) were genotyped using six microsatellite DNA loci. For the D-loop control region, samples from natural sites exhibited higher numbers of haplotypes and haplotype diversities compared to farmed samples, and 88.2% of haplotypes were private. All except LJP and LTA shared haplotypes, and the highest number of shared haplotypes (8) was detected in KIB. The 68 haplotypes we found in 268 individuals grouped into five phylogenetic clades: LVG/LKG, LTA, LBA, LJP and SAG. Haplotypes of farmed C. gariepinus mostly have haplotypes typical of LVG/LKG, and some shared haplotypes of the LBA population. Microsatellite analysis showed farmed samples have higher numbers of alleles than natural samples, but higher observed and expected heterozygosity levels were found in samples of natural populations. Fifteen pair-wise comparisons had significantly different FST values. All samples were in Hardy-Weinberg equilibrium. Samples from the eight localities grouped into four genetic clusters (LVG/LKG, LTA, LBA and SAG), indicating genetically distinct populations, which should be considered for aquaculture and conservation

Genetic diversity of endangered sandalwood (Osyris lanceolata) populations in Kenya using ISSR molecular markers

Osyris lanceolata is an evergreen, drought tolerant tropical African tree species belonging to the family Santalaceae. It is endangered, owing to overexploitation for its essential oil used in cosmetics and pharmaceutical industries. The study aimed at determining: (1) the genetic diversity; and (2) the population genetic differentiation in seven key O. lanceolata populations, representing its natural distribution in Kenya. Genotype data for ISSR neutral molecular markers were generated for seven populations of O. lanceolata. The percentage of polymorphic loci (P), ranged from 51% (Wundanyi) to 82% (Gwasii), with a mean of 65%. The mean number of effective alleles (Ne) was 1.430, whereas the Shannon Information Index (I) mean was 0.263. Gwasii population was the most genetically diverse followed by Mt Elgon and least was Wundanyi. The coefficient of differentiation Gst was 0.343. Results of analysis of molecular variance (AMOVA) showed that most of the genetic variation (62%) in O. lanceolata resided within populations. Principal coordinate analysis (PCoA) analysis showed that Baringo population located in the Rift Valley was genetically distinct from the rest of the populations. In conclusion, Gwasii, Mt Elgon and Baringo populations should be delineated for in situ conservation, whereas selection for ex situ conservation should target good trees from all the populations