Physiological response of cauliflower in relation to manganese-boron interaction

Summary

Cauliflower (Brassica oleracea L. var. botrytis) was grown in refined sand at low (0.0011 mg l^?1), normal (0.55 mg l^?1) and excess (5.5 mg l^?1) Mn, each at three levels of B, deficient (0.0033 mg l^?1), normal (0.33 mg H) and excess (3.3 mg l^?1). In Mn deficient cauliflowers a deficiency of B accentuated visible symptoms of Mn deficiency and aggravated the Mn deficiency effects i.e. a decrease in dry matter, leaf Mn, sugars, starch, chlorophyll, Hill reaction and specific activity of aldolase and an increase in the concentrations of proline and inorganic phosphorus. In cauliflowers exhibiting B toxicity symptoms under conditions of excess B, excess Mn increased leaf Mn, sugars, nucleic acids, protein P, nucleic acid P, acid-labile P and leaf B. Excess Mn decreased the concentrations of DNA, protein nitrogen, chlorophyll and activities of peroxidase, aldolase and leaf B, leaf Mn in boron deficient cauliflowers.     

Growth attributes of potato and their inter-relationship with yield

Summary In the mild and short winter of the Ganges plains, the yield contributing characters such as number of shoots/plant, plant height, leaflet size, tuber yield/plant and tuber number/plant were studied for fifty varieties of potato. From the simple, partial and genotypic and phenotypic correlation studies it was observed that leaflet size, number of tubers/plant and plant height were closely connected with the yield of potato tubers. A multiple regression equation was also prepared and it was found that the leaflet size had the maximum influence on yield followed by number of tubers/plant and plant height.     

Evaluation of a new composting method in terms of its biodegradation pathway and assessment of compost quality,maturity and stability

The need for scientific composting methods for effective utilization of organic waste is increasing day by day. In this respect, a new process called the Novcom composting method is being increasingly adopted by the organic tea planters of Assam and Darjeeling (India) for large-scale composting. Study of the biodegradation process under this method and quality evaluation of the end product was carried out at Maud tea estate (Assam) during 2008–2009 and 2009–2010. Generation of high temperatures (>65°C) within the compost heap during the biodegradation process provided an indication regarding the destruction of pathogens and weed seeds in the composted material. Samples collected on day 0, 7, 14, 21 and 30 of composting, were analyzed for physicochemical properties, nutrient status, microbial population, stability and phytotoxicity parameters. The most significant finding was the high microbial population (in the order of 10¹⁶ cfu g^?1) in the final product, which was generated naturally during biodegradation. Assessment of the maturity and stability parameters of the compost indicated that biodegradation was complete in ～3 weeks. The study provided an indication of the potential of the Novcom composting method for the production of good quality, stable and mature compost, within a short period.     

Developmental aberrations in seeds of boron deficient sunflower and recovery

Sunflower (Helianthus annuus L.) cv. Modern grown in refined sand at deficient (0.033 mg L^‐1) boron (B) developed visible symptoms of low B accompanied by marked depression in growth, dry matter, tissue B, flower head size, and seed weight. The B deficient seeds showed a marked decrease in non‐reducing sugars and contents of oil and starch whereas in leaves reducing sugars accumulated. Except for slight increase in leaf B and flower size, resumption of sufficient B (0.33 mg L^‐1) to B deficient plants from the day of anthesis could not appreciably alter the growth, dry matter, head size and seed weight of deficient plants. Apart from this, non‐reducing sugar content in seeds increased on resupplying B to deficient plants. A significant decrease in non‐reducing sugars and starch content in B sufficient seeds by withdrawing B from the day of anthesis indicate a specific role of B in production and deposition of reserve in the seeds of sunflower.     

Physiological and Biochemical Responses of French Bean to Excess Cobalt

ABSTRACT

French bean (Phaseolus vulgaris L.) cv. ‘Anupama’ was grown in refined sand at variable levels of cobalt (Co), i.e., 0.0001 (control), 0.05, 0.10, 0.20, 0.40, and 0.50 mM, supplied as cobalt sulfate. The symptoms of excess Co (0.50 mM) appeared at day 35. In addition to growth depression, the young leaves developed chlorosis from the apex leading toward the base; the chlorosis intensified, changed to necrosis, and the infected leaves dried and withered. Under excess Co (> 0.0001 mM), the flowers produced were fewer in number, smaller, and many failed to mature, leading to lower seed yield. Excess Co (> 0.0001 mM) decreased the biomass, seed yield (number and weight), concentration of chlorophyll, Hill reaction activity, and activity of catalase, and deteriorated the quality of produce (sugars, starch, and protein nitrogen (N)), but it increased the concentration of phenols and activity of certain enzymes, i.e., peroxidase, ribonuclease, and acid phosphatase. The concentration of Co in various parts of French bean increased with an increase in Co supply and that of iron (Fe) decreased concomitantly. The values of threshold of toxicity and toxicity of Co were 26 and 72 μg g^?1 in young leaves of French bean, respectively.     

Carbon nanotubes and nanofibre: An overview

Carbon nanotubes are graphene sheets rolled up in cylinders with diameter as small as 1 nm. Extensive work carried out in recent years has revealed the intriguing properties of this novel material. Exceptional property combined with low density of nanotubes makes them suitable for use as reinforcements in composites. Low volume of production and high cost is the main limitations towards their growth and application. Nanofibres bridge the gap between the conventional carbon fibre and the carbon nanotubes. With their low cost & comparatively higher volume of production along with their exceptional properties, the nanofibres are considered attractive material as nanoscale reinforcement. In this article a concise review of structure, property, production and application of carbon nanotubes and nanofibres have been discussed.     

Crystallization behaviour of PP and carbon nanofibre blends

Crystallization behaviour of blends of different MFI isotactic polypropylenes (PP), and blends of PP with carbon nanofibre have been investigated by DSC and polarizing optical microscope. Both higher MFI PP component and the carbon nanofibre in the blend influence the nucleation activity of the melt during non-isothermal crystallization. In presence of carbon nanofibre, the sherulitic growth rate is highly disturbed. The calculation of nucleation activity indicates that carbon nanofibres act as active substrate for heterogeneous nucleation.     

Traditional versus improved agroforestry systems in Vietnam: a comparison

Combined with the diverse biophysical and social heterogeneity encountered in the northern mountains, the socioeconomic changes in Vietnam that accompanied the decollectivisation process led to complex agrarian dynamics that today challenge traditional farming and management of natural resources. Data for this study were collected from villages in and around Ba Be National Park (BNP) in the Bac Kan Province located in the northern mountains of Vietnam. Traditional slash and burn cultivation is no longer a sustainable practice in Vietnam. The main challenges in the region are to protect biodiversity, maintain the land productivity and simultaneously support local livelihoods. The study shows that improved agroforestry cultivation could provide significantly higher productivity and income per unit of land, besides decreasing pressure on natural forests. The challenge to protect biodiversity is not met, as improved agroforestry implies less tree species. From an institutional and socio‐economic perspective, it is not easy for local communities to readily adapt to improved agroforestry. New systems must be tailored site‐specific to the diverse local conditions of resource‐poor farmers. Copyright © 2006 John Wiley & Sons, Ltd.     

A nontoxic antitumour compound from the leaves of Bauhinia scandens characterized as 1-O-alkyl glycerol by gas–liquid chromatography and evaluation of its antitumour property by Brine Shrimp bioassay

This is a report of extraction and identification of 1-O-alkyl glycerol present in the dried leaves of Bauhinia scandens. Fifty percent aqueous ethanolic extract of the plant at room temperature was fractionated over petroleum ether and diethyl ether. The diethyl ether soluble fraction showed positive bioactivity in Brine Shrimp bioassay. Isolation and purification of the active principle was subsequently done from diethyl ether fraction. The diethyl ether fraction was separated into acidic and neutral part. The acid free fraction was screened to be positive in Brine Shrimp bioassay. The NMR spectra (in CDCl₃) indicated the probability of its lipoidal nature. The total lipid fraction was resolved into neutral, glyco, and phospho-lipids by column chromatography. Only the neutral fraction showed positive response to Brine Shrimp toxicity test, out of which again a Brine Shrimp positive fraction was separated by thin layer chromatography and identified as 1-O-alkyl glycerol. This fraction was acetylated and GLC analysis of the 1-O-alkyl-2,3-diacetyl glycerol was done. Our results demonstrate that the work may be cited as a nonhazardous and nonchemical management of therapeutic importance.     

Calcium-dependent stress maintenance without myosin phosphorylation in skinned smooth muscle

Stress development depended on calcium-stimulated myosin phosphorylation in an arterial smooth muscle preparation in which the concentration of calcium was controlled. However, developed stress was maintained at a concentration of calcium that did not support phosphorylation. These results, in conjunction with other evidence, suggest that the interaction of two regulatory mechanisms with different calcium sensitivities regulate both stress and the rate and energetics of contraction.