Annual Research & Review in Biology

Background: Eruca sativa (E.S.) is a worldwide herbaceous plant usually used for salad preparations and in traditional medicine for their therapeutic properties.

Aims: This study aimed to determine the effect of ethanolic extract of Eruca sativa leaves (E.S.) on testosterone levels, and histological changes of testes.

Methodology: Fourteen albino male rats were divided into two groups: Group A, rats served as controls. Group B, the rats dosed orally with 500 mg kg-1 of extract daily for 4 weeks. Student’s t-test was used to compare the mean values of experimental group and control.

Results: The results showed that final body weight was significantly lower (P<0.05) than in the control. A significant increase (P<0.05) of testes weight was observed as compared with control. Significant differences (P<0.05) were also found in the mean concentration of testosterone between the experimental group and the control (6.294 ng/ml and 3.256 ng/ml, respectively).The dose caused a significant increase (P<0.05) of total protein and total cholesterol value, compared to the control. On the other hand, a significant reduction (P< 0.05) of triglycerides was observed. The histological study showed a decrease in the interstitial space, an increase in the diameter of seminiferous tubules, spermatid and leydig cells compared with the control.

Conclusion: Ethanolic extract of E.S. leaves could increase fertility potential and testosterone concentration in male rats. This plant seems to reduce serum cholesterol levels with some alterations in the structure and ultrastructure of the testes when this dose (500 mg kg^-1) has used.

The scope of the study was to explore and simulate some selected abiotic factors from the natural home of the shrimps (a tropical rainforest river) with a view to providing information required for sustainable shrimp husbandry.

Hypothesis: Abundance of shrimps is solely a function of the physico-chemical (abiotic) characteristics of the river.

Methodology: Water, sediment and shrimp samples were collected on monthly basis from the Osse River, in Edo State, Nigeria. The samples were collected between April and December, 2015; at night and early morning periods. The physico-chemical properties of the water and sediment samples were analyzed in the laboratory. The shrimp samples were identified, sorted, and counted. Analysis of variance was employed in analyzing the descriptive statistics of the physico-chemical properties. Sex distribution patterns amongst the shrimp species and the ratio of male to female distribution for each species was analyzed mathematically. Stress levels impacted by abiotic variables were investigated employing Cytochrome P450 mono-oxygenase (CYP450), Glutathione-S-Transferase (GST), Catalase (CAT), Superoxide dismutase (SOD) and Lipid Peroxide (LPO).

Results: Availability of the shrimps in the study area was: Macrobrachium vollenhovenii >Macrobrachium macrobrachion >Macrobrachium lux >Macrobrachium fellicinium >Nematopalaemon hastatus > Palaemon maculatus. The female shrimps outnumbered the males in among all the species captured from the natural environment. Order of abundance of shrimps in the river was Station 2 (41%) > Station 1 (32%) > Station 3 (16%) > Station 4 (11%).Abundance of shrimps at Station 2 can be attributed to the predominant abiotic factors such as flow rate (0.1 ± 0.01 m/s), depth (72.5 ± 3.1 cm, water pH (6.7- 7.5), water temperature (27.6 ± 1.07 °C), and primary productivity nutrients (oligotrophic).  Laboratory results conform to field observations on the basis of depth having greater impacts on the organisms than flow rate.

Conclusion: Palaemonid shrimps are littoral organisms which have considerable cultivability. Depth of 72 cm and flow rate of 0.1 m/s are recommended for aquaculture of the shrimps. Notwithstanding, sufficient information about their feeding habits and breeding conditions are imperative.

Aims: To find out whether flavonoid-rich fractions of aqueous and methanolic extracts of gamal plant leaves, Gliricidia sepium (Jacq.) Kunth ex Walp., can be used for eradicating coffee mealybugs, Planococcus citri Risso.

Study Design: Completely randomized design using five concentration levels repeated three times.

Place and Duration of Study: Department of Biology, Faculty of Mathematics and Sciences, University of Lampung, Bandar Lampung, Indonesia between December 2015 and May 2016.

Methodology: Mealybugs that found to infest coffee berries (Coffea robusta L.) were reared and grouped into two. Both groups were fed consecutively with flavonoid fractions of aqueous and methanolic extracts of gamal plant leaves with the concentration of 0% (as control), 0.01%, 0.02%, 0.03%, and 0.04%. The percent mortality of insects was examined at the 12th, 24th, 48th and 72th hour.

Results: Thin layer chromatography analysis of aqueous and methanolic extracts yielded consecutively one and seven fractions of flavonoid.  Both type of extract affected mortality rate of the insects in a concentration-related manner, however based on LC₅₀ and LT₅₀ values the water fractions showed a higher effectiveness than that of methanol.

Conclusion: It is suggested that flavonoid-rich fraction of gamal leaf extracts is potent to be used as bioinsecticide for coffee mealybugs, Planococcus citri Risso.

Monga is seasonal food insecurity in ecologically vulnerable and economically weak parts of north-western Bangladesh, primarily caused by an employment and income deficit before Transplanted aman paddy (summer rice) harvest. It mainly affects those rural poor, who have an undiversified income that is directly or indirectly based on agriculture. Rangpur and Lalmonirhat districts under greater Rangpur region are severely affected by Monga. For increasing employment and food accessibility in these regions this study was undertaken. The farm accounting data for this empirical application have been collected from two districts (Rangpur and Lalmonirhat) of greater Rangpur through a farm management survey. A sample of 90 farms from each district has been surveyed taking 30 from marginal, 30 from small and 30 from medium farm groups using random sampling technique method. Farmers get lower return due to lack of crop diversification. Linear programming model used to produce optimum farm plans for marginal, small and medium farms (i) by reorganization of existing resources (ii) by combination of improved technologies with existing technologies. For increasing food accessibility and employment, optimum farm plans by reorganization of improved technology have been conducted among six farmers in the study villages at 2010-2011. By reorganization of existing cropping patterns (using Linear Programing Model) gross output (7% to 21%), gross margin (12% to 20%) and labour employment (6% to 20%) have been increased from plan1 (existing plan) to plan 2 (by reorganization of existing lands). The cause of increase gross output, gross margin and labour employment was some cultivated land from less efficient cropping patterns has been transferred to more efficient cropping patterns. Again, by reorganization of existing and improved cropping patterns, some lands of existing patterns have been shifted to improved cropping pattern. As a result, gross out (17% to 31%), gross margin (27% to 32%) and labour employment (13% to 26%) have been raised from plan1 to plan 3 (by combination of improved technologies with existing technologies). The result of on farm demonstration showed gross output, gross margin and labour employment have been increased 24% to 53%, 32% to 51% and 12% to 47% from plan1 to plan 3, respectively. So, this study suggest, optimum farm plan with the combination of existing and improved cropping pattern will increase farm output and generate additional employment.

Transformation is one of the few options for horizontal gene transfer. Though transformation is a natural process, yet only a handful of the organisms are able to perform it naturally. The process of bacterial transformation is also a step of pivotal importance in the field of genetic engineering. The rDNA which is an exogenous DNA, is required to be inserted and expressed in the suitable host. However, majority of the hosts are unable to take up exogenous DNA. Thus, it requires some artificial methods too. The induction of the ability to take up such DNA is called competence. Several methods are being tried since the inception of its concept, but none of them are found to be universal. Therefore, there is a constant requirement of newer methods having advantage and efficiency over the existing ones. The conventional method involves CaCl₂ treatment followed by heat shock for achieving transformation. There is also employment of device oriented high end methods like electroporation or ultrasound mediated transformation etc. The efficiency of such methods varied widely and is often specific to a host. Thus, this review is focused on the necessity of transformation and various options that are available to researchers for performing bacterial transformation. It also attempts to strike a comparative study of the existing techniques.