Volume 16, Issue 4, 2016 October-December


Volume 16, No 4 Pages:
2016 October-December Articles: 4

Soil health: Importance, options and challenges in Mizoram

Soil health plays as an important role for food security and sustainable agriculture. Besides, soil organic carbon which acts as a store house for plant nutrients, balancing of nutrients and proper soil physical condition is needed to maintain a healthy soil. With the launched of soil health card scheme, many farmers will be benefited by understanding the soil condition and the amount of nutrients to be applied which will increase food productivity. However, to meet the food requirement of the state and realizing the role played by soil for sustainable production. Several challenges lie ahead where more research and developments have to be emphasized. This includes site specific nutrient management, proper integration of nutrient including organic and inorganic, better utilization of nitrogen fixers and re structuring soil testing laboratories. Key words: Soil health, food productivity, site specific, nutrients, soil test.


Observation on the breeding behaviour and analysis of the advertisement calls of Rhacophorus maximus G├╝nther, 1858 (Anura: Rhacophoridae)

The breeding behaviour and the advertisement calls of the giant tree frog, Rhacophorus maximus was studied during the breeding season in Mizoram University Campus, Aizawl, Mizoram. At the first shower of the onset of monsoon, advertisement calls of male attract females to breeding areas and announce other males that a given territory is occupied. The aim of this study was to provide the detailed information on the breeding behaviour and analysis of advertisement calls of Rhacophorus maximus. Advertisement calls were emitted in series with variable call intervals. The morphometric measurement of the amplecting pairs were recorded and females are found to be larger than males. Key words: Breeding behaviour, advertisement calls, Rhacophorus maximus, Mizoram.


Studies on the effect of heavy metals on soil fungi Trichoderma sp.

Development of plants is closely related with both the soil quality and the community of soil microorganisms, therefore plants are influenced by heavy metals directly transferring from the soil and indirectly via heavy metal impact on the microorganisms. Copper and Zinc are essential micronutrient, but above certain threshold concentration are toxic to both microbes and humans. Many heavy metals had been used to study the effects on several types of fungi. In this experiment, two heavy metals viz. ZnCl2 and CuSO4 of different concentrations (0.25 mM, 0.5 mM, 1 mM, 2.5 mM and 5 mM) were used to study their effect on selected fungi. The result from this experiment reveals that ZnCl2 and CuSO4 have negative effect on Trichoderma sp. in their growth rate and reduce the production of spores with the increasing concentration of the heavy metals. In the present study, CuSO4 showed greater inhibitory effect on the growth of Trichoderma sp. than the concentration of ZnCl2. Keywords: Heavy metals, hydrocarbons, mycoparasitism, Trichoderma.


Studies on the effect of ZnCl2 on phosphatase enzyme activity and biomass of Pseudomonas fluorescens (ATCC® 13525TM)

Living organism requires certain metals for their growth and metabolism and evolved an appropriate uptake mechanism for metals. However, it is particularly difficult to establish mutual relationship when soil is continuously contaminated with various heavy metals. Phosphatase enzyme significantly accelerates the release of inorganic P from organic compounds and returns it to the soil. Therefore, the study of Phosphatase enzyme that releases P from organic compounds by dephosphorylation of phosphor-ester or phosphoanhydride bond in an organic matter is an important tool in initiating biofertilizer for specific crops. The present study indicated that the availability of metal such as Zinc in its inorganic form can act as an inhibitory factor for the growth and activity of bacteria such as Pseudomonas flourescens and the biomass of P. flourescens decrease with increase ZnCl2 concentration. It can be concluded that ZnCl2 acts as an inhibitor to the growth of P. flourescens and also the presence of ZnCl2 in the growth medium decreases the phosphatase enzyme activity of the bacteria, which reveal that metals can also affect the activity of the microbes. Keywords: Biofertilizers, enzymes, microbial ecosystems, phosphatase, Pseudomonas fluorescens, ZnCl2.


Phytochemical investigations on the medicinal plant Acmella oleracea cultivated in Mizoram, India

Species of the genus Acmella are perennial plants and are well known as traditional medicines and as vegetables in tropical regions. Of these, A. oleracea (L.) R.K. Jansen is the most widely used, and is cultivated as an ornamental plant and as a crop. In traditional medicine, it is used for the treatment of haemorrhage, helminthiasis, gingivitis, laceration, malaria, oral and gastric ulcer and infections, dysentery, urinary calculi, and inflammations. Biochemical tests of the methanol indicated presence of important bioactive compounds, such as phytosterols, and tannins. Assessment of the free radical scavenging activity showed that it has concentration-dependent antioxidant activity similar to that of the standard butylated hydroxytoluene (BHT). The half maximal inhibitory concentration (IC50) of the plant extract was 13.773 mg/ml, while it was 28.098 mg/ml for BHT. The total antioxidant activity was 85 mg/ml calculated against the standard ascorbic acid. The total phenol content was estimated using Folin-Ciocalteu-gallic acid reaction, and was determined to be 1.38 GAE mg/g. Using the aluminum chloride-quercetin assay, the total flavonoid content was calculated to be 28.7 QE mg/g. Keywords: A. oleracea, antioxidant activity, total phenol, total flavonoid.