Physicochemical Characteristics of Soil from Selected Solid Waste Dump Sites in Port Harcourt, Rivers State, Nigeria

This study examined the nutrient status and textural characteristics of soil from solid waste dumpsites in the city of Port Harcourt. The study was carried out in five solid waste dump sites alongside their respective controls located at Iwofe, Eliozu, Choba, Rumuokwuta and Ozuoba within the city of Port Harcourt for two seasons (wet and dry). A systematic sampling technique was employed for field sampling. Soil sample was collected with soil auger and analysis was done using standard methods. Results showed mean pH value (4.86±0.18 – 7.66±0.44) and; cation exchange capacity (2.2±0.3 -18.11±0.8 meq/100g). The mean electrical conductivity indicated higher conductivity in the control sites (125±5.5 - 492±16 μs/cm) than the dump sites (32.06±2.5 – 299.5±1.5μs/cm).There was high nutrient concentrations in the dump site soils of total nitrogen (0.04±0.01 – 0.62±0.13%); phosphorus (0.041±0.01 – 4.07±0.02mg/kg); potassium (9.19±2.5 – 326±51.91mg/kg) than the controls. On the contrary, there was no significant difference between the soil particle size distribution of the dump site soil and their respective controls. The soil particle size distribution indicated an average of 83% sand, 11% clay and 5% silt, while the soil texture was loamy sandy for all the dump sites except the dump site located at Iwofe. Therefore, solid dumps alter the soil nutrient contents with no significant change in the textural nature of soil. Key words: Solid wastes, Soil, Particle size, Nitrogen, Nutrient, Dump site

Breaking Dormancy In Gmelina arborea Roxb. Through Treatment Of Seeds With Chemical Substances And Alternating Temperature

Seeds of Gmelina arborea Roxb. were subjected to different treatment [chemical scarification with concentrated sulphuric acid (H2S04), potasium nitrate (KNO3), potasium nitrite (KNO2) and alternating temperature regimes] to ascertain the best treatment for terminating dormancy in the seeds. Initial viability and germination tests showed that the seeds of G. arborea are viable but dormant. Seed viability percentage of 96 was recorded. Dormancy in the seeds was found to be the physical type caused by hard seed coat. Chemical scarification for 10 minutes with concentrated H2S04 was very effective in breaking seed dormancy in the species. This increased water uptake in the seeds to 68% compared with the 15% in unscarified seeds after 7 days. Scarification gave a germination percentage of 80 over 43% for the unscarified after 26 days. 1mM and 10mM KNO3 and KNO2 terminated dormancy and highly enhanced germination in the scarified than unscarified seeds. Alternating temperatures promoted germination of G. arborea seeds with the best results recorded at 9 cycles of alternating temperature at 30 °C for 16hours and 45 °C for 8 hours. Key Words: Dormancy, Gmelina arborea, Chemicals, Alternating temperature Bio-Research Vol.2(1) 2004: 59-6

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Not AvailableWith an objective to develop and utilize genomic tools for its improvement, a total of 350 EST clones from the root tissue of this wild relative were developed and sequenced. Sixty-three EST sequences were submitted to NCBI. Twenty-six primer pairs were also designed based on sequences flanking the microsatellite motifs using PRIMER v. 3.0 software. The primer pairs were amplified on 45 selected pigeonpea genotypes and polymorphic SSR markers were identified. These new markers will add to the pool of available markers and accelerate molecular breeding for pigeonpea improvement.Not Availabl