A substoichiometric radiochemical extraction method has been developed for the determination of cerium employing a chelating agent -hydroxy-naphthaldoxime, dissolved in isoamyl alcohol. The reagent was synthesised and characterised in our laboratory. The method developed was utilized to determine the cerium content of some natural samples.
Determination of mercury (II) by substoichiometric extraction with malonic anilide into a mixture of ether and MIBK is reported. The method has been applied in the estimation of the metal in industrial effluents.
Effect of Trichoderma viride T1433 on the pectolytic enzyme activity of Rhizopus stolonifer (= R. artocarpi) during the development of soft rot of jackfruit was studied. Activity of different fractions of pectolytic enzymes like PG, PME and PL was investigated during pathogenesis and correspondingly the associated resistance of the host was assayed. It was noticed that the biocontrol agent, Trichoderma significantly interacts with the pectolytic enzyme activity of the pathogen. It caused an appreciable reduction in enzymatic action. The reduction in the activity of polygalacturonase enzyme (PG) was recorded to be the highest among all the fractions of pectolytic enzymes. Such a trend appeared to be more pronounced in 'Kujja' than in 'Ghula' cultivar of jackfruit. The reduction in pectolytic enzyme activity was found to be coupled with a significant increase in the activity of polyphenol oxidase enzyme of the host tissues and a concomitant increase in host phenol content. Such inter-relationship between these two enzyme systems plays a key role to stimulate the defense mechanism of the host plant against infection. Significant increase in total phenol content of the host tissue during Trichoderma plant pathogen interaction that was recorded may correspond with the host defense response.
Authors:R. Dutta, S. Chintalapudi, and S. Bhattacharyya
A radiochemical procedure for separation of carrier-free22Na from bulk of Mg is described. The method involves the initial removal of bulk of Mg as Mg(OH)2 by means of ammonia followed by separation of the last traces of Mg by means of extraction with a cationic liquid exchanger,
di-(2-ethylhexyl) phosphoric acid (HDEHP) in cyclohexane.
A radiochemical solvent extraction method for the determination of iron(III) employing the chelating extractant malonic anilide (MA), synthesized in our laboratory, has been described. Effects of different parameters on the extraction of iron(III) from 2M hydrochloric acid into a mixed organic solvent (methyl isobutyl ketone (TIBK) and diethyl ether) have been studied in detail. The method was applied for the estimation of iron content in several fruits using the principle of substoiciometric isotope dilution analysis.
Authors:M. R Chakraborty, S. Dutta, S. Ojha, and N. C. Chatterjee
Biological control of die-back of bottle brush (Callistemon citrinus) caused by Botryodiplodia theobrome was made with the application of antagonistic agents like Trichoderma viride, T. lignorum, T. harzianum, Aspergillus niger and Penicillium citrinum. The effect of volatile and non-volatile antibiotics of Trichoderma origin on growth inhibition of the die-back pathogen was studied. T. harzianum showed maximum growth inhibition (75.33%) of the pathogen through mycoparasitism and the non-volatiles produced by the same agent exhibited its excellent antagonism to the growth of the pathogen (91.11%) under in vitro condition and that the effect was also proved to be durable.
Authors:M. Chakraborty, I. Ghosh, S. Ojha, S. Dutta, and N. Chatterjee
Influence of an endomycorrhizal species
on the growth of two vegetable plants, namely,
and for reduction of the incidence of fusarial wilt disease under field condition was studied. VAM treated plants showed more vigor in terms of productivity parameters viz., plant height, number of branching twigs and fruit production. VAM and pathogen treated plants also showed positive effect of VAM-symbiont over control indicating reduction of pathogenic stress of the plant and give resistance. Leaf phosphate, chlorophyll content and percentage of mycorrhization were recorded highest when plants were singly inoculated with
. Synergistic effect of VAM and pathogen to increase on productivity vis-à-vis resistance was also studied in respect of polyphenol oxidase. The experimental findings indicated the potential use of
for improving the growth and imparting resistance of brinjal and tomato.