Effect of composting on extractability and relative availability of heavy metals present in Calcutta municipal solid waste

How composting affects heavy metal content is largely unknown. Accordingly, we investigate the total content of six heavy metals, Cd/Zn ratio and the Zn-equiv, the relative availability and fractionation study to assess the suitability of compost derived out of those for environmental concerns. During composting, total metal content increased but their RA decreased. As a result of composting bioavailable form of metals also decreased. High significant correlations between different forms of heavy metals content and degree of humification were found for all the elements. Composting increases humic acid content than fulvic acid. This transformation is mainly responsible to serve as binding agent for metal thereby moderating the rapid metal mobilization.     

Implication of melatonin in oocyte maturation in Indian major carp Catla catla

Importance of melatonin (N-acetyl-5-methoxytryptamine) in the regulation of oocyte maturation has been studied in a carp Catla catla. Melatonin secretory cells were immunocytochemically localized only in the end vesicle. Diurnal and seasonal studies indicated that the serum levels of melatonin exhibit a minimum diurnal value in the mid-day of all seasons, but the peak value is attained either at mid-night or just before the onset of light. Moreover, highest seasonal value of melatonin was noted in the post-spawning phase. Administration of melatonin at different doses (25, 50, or 100 μg/100 g body weight) for 1, 15, or 30 days resulted in either pro- or anti-gonadal effects depending on the reproductive seasons. In vitro study revealed that incubation of oocytes with melatonin 4h prior to addition of MIH in the medium led to an accelerated rate of oocyte maturation through the formation of a complex of two proteins (MPF), cyclin B and cyclin dependant kinase, Cdc2. Moreover, melatonin pre-incubation considerably increased MIH stimulation of histone H1 phosphorylation as compared to MIH alone. Taken together, gathered information promotes the idea of a physiological role of melatonin in the maturation of oocytes in Catla catla.     

Greenhouse gases emission,soil organic carbon and wheat yield as affected by tillage systems and nitrogen management practices

Agricultural activities are responsible for greenhouse gases (GHGs) emission in the environment. Strategies are required to enhance the soil organic carbon (SOC) and nitrogen (N) sequestration to adapt and mitigate the climate change. We investigated GHGs emission, SOC and N enhancement under conventional tillage (CT) and zero tillage (ZT) with N management in wheat (Triticum aestivum L.). Seasonal carbon dioxide (CO₂) emission and global warming potential (GWP) reduced for ZT treatments over CT without residues and 100% of required N with a blanket split application (CT – R + 100N). The ZT with 5 t ha^?1 maize (Zea mays L.) residues retention and 75% of required N and GreenSeeker^TM (GS)-aided N management (ZT + R + 75N + GS) reduced yield-scaled GHGs emission and increased total organic carbon (C) stock over CT – R + 100N. However, nitrous oxide (N₂O) emission was lower in CT. The GS-based N management saved 26–35 kg N ha^?1 in different tillage systems in both years over blanket application with higher N uptake and associated reduction in N₂O emission. The study recommends that ZT with residues retention and GS-based N management can minimize the GHGs emission and improve the SOC.     

Nitrate leaching,nitrous oxide emission and N use efficiency of aerobic rice under different N application strategy

A field study was conducted in the sub-humid tropical region of India to examine the effect of different nitrogen (N) management strategies on nitrate leaching, nitrous oxide (N₂O) emission and N use efficiency in aerobic rice. Treatments were: control (no N), 120 kg N ha^?1 applied as prilled urea (PU) in conventional method, 120 kg N ha^?1 applied as neem coated urea (NCU) in conventional method, N applied as PU on the basis of leaf colour chart (LCC) reading, N applied as NCU on the basis of LCC reading, and 120 kg N ha^?1 applied as PU and farm yard manure (FYM) in 1:1 ratio. Results showed that 3.4–16.1 kg NO₃-N ha^?1 was leached below 45 cm depth and 0.61–1.12 kg N₂O-N ha^?1 was emitted from aerobic rice during the growing season. NCU when applied conventionally reduced nitrate-nitrogen (NO₃-N) leaching and N₂O emission by 18.6% and 21.4%, respectively However when applied on the basis of LCC reading NCU reduced NO₃-N leaching by 39.8% as compared to PU applied in conventional method. NCU when applied on the basis of LCC reading synchronized N supply with demand and reduced N loss, which resulted in higher yield and N use efficiency.     

Temperature-induced susceptibility of soybeans to Phytophthora megasperma f.sp. glycinea: phenylalanine ammonia-lyase and glyceollin in the host; growth and glyceollin I sensitivity of the pathogen

In unwounded soybean hypocotyls, pulse labelled with [¹⁴C]phenylalanine and inoculated with Phytophthora megasperma f.sp. glycinea, rates of [¹⁴C]-incorporation and glyceollin I accumulation were higher in resistant than in susceptible responses throughout the time-course of the experiment. This distinction was masked in hypocotyls that were wounded and inoculated. In such hypocotyls, high rates of [¹⁴C]-incorporation developed that were similar for the first 11 h in resistant and susceptible responses, although much more glyceollin I accumulated in the former. High rates of [¹⁴C]-incorporation also developed in uninoculated wounded hypocotyls but only small amounts of glyceollin I of high specific radioactivity were detected. Estimates of phenylalanine ammonia-lyase activity indicated that the metabolic flux through phenylalanine was limited in wounded controls but potentially very high in resistant responses. Differences in rates of [¹⁴C]-incorporation and in specific radioactivity of accumulated glyceollin I presumably indicate differences in the relative contributions of mobile internal pools and externally applied phenylalanine, in addition to rates of biosynthesis. Rapid decline in [¹⁴C]-glyceollin I was demonstrated in wounded controls in pulse-ch0ase experiments with phenylalanine as chase, but not in inoculated hypocotyls, due to continued [¹⁴C]-incorporation during the chase period. Rapid metabolism was demonstrated in all interactions and in wounds when cinnamic acid was used as the chase, but there was no evidence that differences in glyceollin I accumulation were due to differential rates of metabolism. Additional evidence for metabolic activity was provided by pulse feeding with [¹⁴C]glyceollin I. It is concluded that the stimulus of wounding or infection induces a metabolic pathway in which glyceollin I is not an end product. The accumulation of higher levels of glyceollin I in resistant than in susceptible responses appears to be due to earlier initiation and subsequently higher rates of biosynthesis in the former.     

Tumour inhibitory activity of chicory root extract against Ehrlich ascites carcinoma in mice

The tumour-inhibitory effect of an ethanolic extract of chicory root was studied against Ehrlich ascites carcinoma in mice; significant results were obtained at doses from 300 to 700 mg/kg.