ABSTRACT
In order to assess the antibacterial activities of methanolic and aqueous leaf extracts (MLE and ALE) as well as that of methanolic berry extract (MBE) of Lantana camara Linn, we screened each for antibacterial effects against 14 bacterial isolates using agar-well diffusion method at concentration of 25mg/ml with streptomycin as control antibacterial. Data obtained were analyzed with ANOVA and t-test using SPSS 15.0 for Windows. The MLE is comparable to streptomycin in antibacterial activity as they both showed antibacterial activity against 13 (92.86%) bacterial isolates with inhibition zone diameter (IZD) of 12mm-20mm. The ALE and MBE however, showed inhibitory activities against 3 (21.43%, IZD 10mm- 11mm) and 7 (42.86%, IZD 11mm-17mm) bacterial isolates respectively. Flavonoids, saponin and alkaloids were present in the three extracts while phlobatannin, cardiac glycoside and steroid were absent. Terpenoids and tannin were only present in the MBE and MLE respectively. Sodium, potassium, calcium, magnesium and zinc were observed in the leaf and berry of Lantana camara. Iron, copper and manganese were present in trace amount with lead (Pb) totally absent. Though the three extracts showed antibacterial effects against the isolates, the MLE was the most effective. The phytochemical analysis revealed that Lantana camara has compounds with antibacterial activities and can possibly be used as alternative therapy to infections caused by the sensitive study bacteria.
ABSTRACT
We studied seed germination and seedling growth of the Mexican sunflower Tithonia diversifolia in Nigeria. This involved the usage of some dormancy-releasing methods and the effect of some concentrations of three herbicide formulations on the young seedlings. Initial germination tests on fresh and stored seeds revealed a low percentage germination of less than 30%. The seeds of the weed exhibit dormancy. Subjecting the seeds to wet heat at 80 and 100 degrees C and light treatment terminated dormancy both in the fresh and stored seeds. Light greatly enhanced the germination percentage of seeds by about 70%. There was gradual increase in germination percentage with increase in storage period in dormancy-released seeds. The mean LAR (Leaf Area Ratio), NAR (Net Assimilation Rate) and RGR (Relative Growth Rate) are comparatively high in young seedlings. Concentrations of 0.5-2.0% of Gramoxone, Primextra and Galex are toxic to 1 month old seedlings. For eradication, the seedlings should be attacked at one month stage.
Se estudió la germinación y crecimiento de las plántulas del girasol mexicano Tithonia diversifolia. Se usaron métodos de periodo de latencia y germinación, y el efecto de varias concentraciones de tres herbicidas sobre las plántulas jóvenes. Las pruebas iniciales de germinación con semillas frescas y almacenadas revelaron un bajo porcentaje de germinación (30%). Las semillas de malezas permanecieron latentes. Al someter las semillas a tratamientos de calor húmedo de 80 y 100oC y luz se terminó con el periodo de latencia en las semillas frescas y en las almacenadas. La luz aumentó el porcentaje de germinación a cerca del 70%. Hubo un incremento gradual en el porcentaje de germinación en el periodo de almacenamiento en las semillas salidas de la latencia. Los promedios de cociente de área foliar, tasa neta de asimilación y tasa de crecimiento relativo son comparativamente altos en las plántulas jóvenes. Las concentraciones de 0.5-2.0% de Gramoxone, Primextra y Galex son tóxicas para las plántulas de un mes de edad.