Soil Seed Bank Dynamics in Tithonia diversifolia Dominated Fallowland Vegetation in Ile-Ife Area of Southwestern Nigeria

The soil seedbank of Tithonia diversifolia, an invasive species which dominates open waste fallowland vegetation was studied. Two different roadside sites which vary in extent of open waste land were selected.The species composition of the established vegetation was assessed in the two diferent sites. Twenty top soil samples were collected at five different distances (15 cm, 30 cm, 45 cm, 60 cm, and 75 cm) inwards away from each main road in dry and rainy seasons and the seed bank composition was determined by greenhouse germination over a 6 month period. The similarity between the composition of the seed bank flora and that of the established vegetation was low. The least and the highest emerged seedlings density was recorded in the 15 metres and 75 metres respectively inwards away from the main road in both seasons. The results of the seedlings emergence is a reflection of the extent of open waste land dominated by the invasive species due to human disturbance (road construction) on both sites. Overall results suggest that the emergence of the species from the soil seed bank may be due to the impact of the invasive species Tithonia diversifolia on other plant species in the study environment

Leaf Protein Electrophoresis and Taxonomy of Species of Jatropha L. (Euphorbiaceae)

The systematic relationship existing among members of the all important genus Jatropha was studied using leaf protein electrophoresis. The aim was to identify possible taxonomic importance of the protein profile in the estimation and elucidation of the taxonomic affinity of the six species of Jatropha (Jatropha curcas Linn., J. podagrica Hook., J. gossypifolia Linn., J. mutifida Linn., J. tanjorensis Ellis & Saroja and J. integerrima Linn.) found in Nigeria. The species were screened for total protein banding patterns using gel electrophoresis. Young leaves (0.8 g) of the plants were washed with distilled water and macerated with sterile mortar and pestle in 0.8% Phosphate Buffer-Saline (PBS) containing 0.4 M NaCl at pH 8.0. Results reveal that protein banding pattern was taxon specific. Generic band occurs at 8.3. The highest number of interspecific bands (4) exists between J. podagrica and J. multifida. Variations exist not only in the number of bands but also in the intensity of the bands. Sokal and Sneath coefficient of similarity ranges between 11.1-44.4 %. Single linkage Cluster Analysis (SLCA) of the relative mobility values of the protein in the taxa shows partial agreement with current sub generic and sectional delimitation of the species based on morphology and anatomy of the species

Pollen Grain Morphology of Some Selected Species of Asteraceae in South Western Nigeria

Pollen morphology and diversity of twelve species of the Asteraceae were collected from different locations within Ile-Ife, South Western Nigeria and acetolysed. The parameters used for the characterization are: diameter of pollen grains, pollen wall thickness, number of pores, thickness between pores, length of spines and number of colpi. The pollen grains of the species studied are spheroidal in shape, in the group media and minuta, either echinate or spinate, yellow to yellowish brown, polypentaporate, tricolporate, acolpate and polycolporate, spines are short with thin walls and pores are densely situated and the measurements taken showed variations from species to species. The similarities in structure showed interspecies relationships and reasons for them to be in the same family while the interspecific variations in structures substantiate their existence as distinct species