Biomedical subjects

S V S Chauhan

Publications and source records attributed to S V S Chauhan.

6 recordsLinked to original sources

PubMed2006

Induction of plant defense enzymes and phenolics by treatment with plant growth-promoting rhizobacteria Serratia marcescens NBRI1213.

In greenhouse experiments, plant growth-promoting rhizobacteria (PGPR) Serratia marcescens NBRI1213 was evaluated for plant growth promotion and biologic control of foot and root rot of betelvine caused by Phytophthora nicotianae. Bacterization of betelvine (Piper betle L.) cuttings with S. marcescens NBRI1213 induced phenylalanine ammonia-lyase, peroxidase, and polyphenoloxidase activities in leaf and root. Qualitative and quantitative estimation of phenolic compounds was done through high-performance liquid chromatography (HPLC) in leaf and root of betelvine after treatment with S. marcescens NBRI1213 and infection by P. nicotianae. Major phenolics detected were gallic, protocatechuic, chlorogenic, caffeic, ferulic, and ellagic acids by comparison of their retention time with standards through HPLC. In all of the treated plants, synthesis of phenolic compounds was enhanced compared with control. Maximum accumulation of phenolics was increased in S. marcescens NBRI1213-treated plants infected with P. nicotianae. In a greenhouse test, bacterization using S. marcescens NBRI1213 decreased the number of diseased plants compared with nonbacterized controls. There were significant growth increases in shoot length, shoot dry weight, root length, and root dry weight, averaging 81%, 68%, 152%, and 290%, respectively, greater than untreated controls. This is the first report of PGPR-mediated induction of phenolics for biologic control and their probable role in protecting betelvine against P. nicotianae, an important soil-borne phytopathogenic fungus.

Hydroxybenzoates↗

PubMed2006

Seasonal phytoplanktonic diversity of Kitham lake, Agra.

Two years (Jan. 2000 - Dec. 2001) data on the seasonal studies of phytoplanktonic diversity of Kitham lake (Sur Sarovar) Agra revealed the presence of 73 algal species. A limited number of these were recorded throughout the year, while others were distributed in different seasons mainly in winter and summer seasons. During winters, Chlorophyceae was the most dominant group followed by Bacillariophyceae. On the other hand, Cyanophyceae and Euglenophyceae were the most dominant during summers. Certain species e.g. Pandorina morum, Pediastrum tetras, Gonium sp., Chlorella vulgaris, Scendesmus quadricauda, Oedogonium cardiocum, Synedra ulna, Oscillatoria agardhii and Euglena gracillis were recorded throughout the year. Chlorella, Stigeoclonium, Pandorina, Micratinium, Oscillatoria, Anacystis, Nitzschia and Cymbella were found to be good indicators of water pollution.

Animals↗

PubMed2004

Optimization of procedures for isolation of mycobacteria from soil and water samples obtained in northern India.

For isolation of environmental mycobacteria, a decontamination procedure has been standardized by which treatment with 3% sodium dodecyl sulfate plus 4% NaOH (15 and 30 min for rapid and slow growers, respectively) is followed by incubation with 2% cetrimide (5 and 15 min for fast- and slow-growing mycobacteria, respectively); this procedure was found to completely eliminate contamination with other organisms and resulted in the isolation of only mycobacteria.

Bacteriological Techniques↗

PubMed2004

Role of phenolics and boron in reproductive success in seasonally transient sterile Tecoma stans L.

Quantitative and qualitative analysis of phenolics and boron in stigma of transient sterile Tecoma stans L. during seedless (May-July), partially seedbearing (August-November, April) and seedbearing periods (December-March) was made. UV absorption profile of stigmatic exudates indicated the presence of simple phenolics. Total phenolics were higher in stigma during seedless period. Thin layer chromatographic analysis of stigmatic extracts exhibited only three principal spots. Mass spectrophotometry showed the presence of derivatives of cinnamic acid, namely, caffeic acid in these spots. Quantity of boron in stigma during seedless period was lowest but the difference with other periods was not significant. It was suggested that the accumulation of higher quantity of caffeic acid in the stigma during seedless period due to high temperature (40 degrees-45 degrees C) could lead to inhibition of pollen germination in vivo, thereby rendering the plants seedless. This was confirmed by inhibition of in vitro pollen germination in the basal medium containing higher quantity of caffeic acid.

Bignoniaceae↗

PubMed2004

Impact of air pollution on floral morphology of Cassia siamea Lamk.

Cassia siamea plants growing at two different sites (polluted and non-polluted) on two important roads of Agra city exhibited significant differences in their flowering phenology and floral morphology. The flowering in plants growing at polluted site is delayed and there was a marked reduction in flowering density, flowering period, size of floral parts, pollen fertility, fruit and seed-set. SEM observations revealed the presence of well developed glandular structures and reduction in the number and size of large stomata on the anther surface at polluted site. These changes were found to be closely associated with the extent of air pollution caused mainly by significant in the number of automobiles.

Air Pollutants↗

PubMed2003

Sample size for collecting germplasms--a polyploid model with mixed mating system.

The present paper discusses a general expression for determining the minimum sample size (plants) for a given number of seeds or vice versa for capturing multiple allelic diversity. The model considers sampling from a large 2 k-ploid population under a broad range of mating systems. Numerous expressions/results developed for germplasm collection/regeneration for diploid populations by earlier workers can be directly deduced from our general expression by assigning appropriate values of the corresponding parameters. A seed factor which influences the plant sample size has also been isolated to aid the collectors in selecting the appropriate combination of number of plants and seeds per plant. When genotypic multiplicity of seeds is taken into consideration, a sample size of even less than 172 plants can conserve diversity of 20 alleles from 50,000 polymorphic loci with a very large probability of conservation (0.9999) in most of the cases.

Alleles↗