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21.
Pot culture experiment was conducted to evaluate the suitability of extractants and to determine the critical limit of boron (B) in soil and mustard plant in Inceptisols of Varanasi. Twenty-one bulk soil collected from different locations were used for growing mustard. Five extractants, namely hot water, hot 0.01molar (M) calcium chloride (CaCl2), 0.01M CaCl2 + 0.05 M mannitol, 1.0 M ammonium acetate (NH4OAC) and 0.05 M hydrochloric acid (HCl), were assessed by correlating the amount of extractable B in untreated and B fertilizer-treated soil with Bray’s per cent yield, plant tissue B concentration and B uptake by mustard. Similarly, correlation coefficients of the B extracted by different extractants and soil properties were calculated. The suitability of B extracted by different extractants was in the order of hot 0.01M CaCl2 (HCC-B) > hot water (HW-B) > 1.0 M NH4OAC (AA-B) > 0.05M HCl (HA-B) > 0.01M CaCl2 + 0.05M mannitol (CCM-B). The critical limits of extractable B in soil as determined by the graphical procedure were 0.54, 0.60, 0.36, 0.45 and 0.45 mg kg?1 and the statistical procedures were 0.54, 0.60, 0.38, 0.46 and 0.48 mg kg?1 with HW-B, HCC-B, CCM-B, AA-B and HA-B, respectively. Soil containing available B below the critical limit responded to B fertilization.  相似文献   
22.
A study was conducted to investigate the effects of paclobutrazol (PBZ) on ion leakage (IL), proline content and activities of antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) of 1-year-old ‘Olour’ mango plants subjected to NaCl stress. Plants were treated with two levels of salt, i.e., 0.0 g NaCl (control) and 25 g NaCl/25 kg soil and three levels of paclobutrazol (PBZ) solution (0.0 (control), 750 and 1500 mg/l). Ion leakage, proline content and activities of antioxidant enzymes were significantly altered by both salinity and PBZ treatments. Results indicated that PBZ (1500 mg/l) mitigated the salinity stress and reduced ion leakage of mango seedlings by 64% over non-PBZ-treated salinised plants. PBZ upregulated the endogenous proline content and salinised plants treated with PBZ (1500 mg/l) had 17% higher proline content than salinised plants without PBZ treatment. Higher antioxidant enzyme activity was also observed in salinised plants treated by PBZ than salinised plants without PBZ treatments. Moreover, higher dose of PBZ (1500 mg/l) resulted in higher activity of these enzymes in mango leaves. In comparison to salinised plants without PBZ treatment, salinised plants treated with PBZ (1500 mg/l) had higher SOD (24%), CAT (46%) and POD (163%) activities. Our results suggest that PBZ application under salt stress conditions alters the equilibrium between free radical production and enzymatic defense reactions in mango by enhancing the proline content and free radical scavenging capacity.  相似文献   
23.
Leaf yellowing symptoms were observed on Acacia mangium in the Sipahijala district of Tripura, India, during June 2017. Symptomatic and asymptomatic leaf samples (three of each) were collected from roadside trees of A. mangium for DNA extraction using the CTAB method. Amplicons of ~1.25 kb and ~480 bp were detected in all the symptomatic samples using the phytoplasma‐specific universal 16S rRNA and secA gene primers. Pair wise sequence analysis of 16S rRNA gene sequences, virtual RFLP and phylogenetic analysis revealed that the phytoplasma strain associated with A. mangium belonged to phytoplasma subgroup 16SrII‐C. This is the first report of an association between the 16SrII‐C subgroup and A. mangium leaf yellowing.  相似文献   
24.
ABSTRACT: In order to ascertain whether the use of drugs as feed additive for fish may cause drug resistance of bacteria in the intestinal tract, viable counts and bacterial flora in the intestine of yellowtail cultivated with the feeds in the presence or absence of various drugs, drug resistance of the flora were determined. Viable counts in the intestine were lowered remarkably by the administration of each drug, suggesting that bacterial growth in the intestinal tract was inhibited by various drugs. Bacterial flora in the intestine consisted mainly of coryneform bacteria, Staphylococcus and Bacillus regardless of whether drugs were administered or not. In these floras, significant differences could not be observed for their resistance to respective drugs among the isolates from fish cultivated with feeds containing or not containing each drug. In addition, these floras mainly showed resistance to various combinations comprising from one to seven drugs; moreover, the majority of resistant strains were multidrug-resistant.  相似文献   
25.
Somatic cell count (SCC), bacteriological findings and electrical conductivity (EC) were measured in milk from 216 quarters of 54 Murrah crossbred buffaloes for characterization of buffalo milk. Mean SCC in normal, subclinical and clinical mastitic milk was 171, 799 and 6039 × 103/mL, respectively. Coagulase negative Staphylococci (CNS) were the major organisms associated with subclinical mastitis, whereas CNS and coliforms were the predominant organisms in clinical mastitis. EC values were found to be significantly higher in buffalo milk with mammary infection. The best trade-off between sensitivity and specificity for diagnosing mastitis in buffaloes by EC score was found at the cut-off value of 3.7 mS/cm. The direct measures such as SCC, EC, bacteriological findings, and appearance of milk were found to be useful for the evaluation of udder health of buffaloes and categorization of milk.  相似文献   
26.
Rethinking organic aerosols: semivolatile emissions and photochemical aging   总被引:4,自引:0,他引:4  
Most primary organic-particulate emissions are semivolatile; thus, they partially evaporate with atmospheric dilution, creating substantial amounts of low-volatility gas-phase material. Laboratory experiments show that photo-oxidation of diesel emissions rapidly generates organic aerosol, greatly exceeding the contribution from known secondary organic-aerosol precursors. We attribute this unexplained secondary organic-aerosol production to the oxidation of low-volatility gas-phase species. Accounting for partitioning and photochemical processing of primary emissions creates a more regionally distributed aerosol and brings model predictions into better agreement with observations. Controlling organic particulate-matter concentrations will require substantial changes in the approaches that are currently used to measure and regulate emissions.  相似文献   
27.
In this study, inoculation of the chickpea (Cicer arietinum) with the novel symbiotic fungus (Piriformospora indica) was analysed in combination with the Tn5-lacZ-tagged phosphate-solubilising bacterium Pseudomonas striata. This study aims to evaluate whether the co-inoculation of these two species would enhance the population buildup of P. striata in the rhizosphere, P uptake, growth and yield of chickpea. Single inoculation of P. indica and P. striata has a negative effect on plant growth and yield of chickpea. Data showed that the combination of the two microorganisms had a synergistic effect on population buildup of P. striata and plant dry biomass with respect to their single inoculation. However, the P uptake was not significantly influenced by single or combined inoculation of two species. At 20 days after sowing, the influence of combined inoculation on the population of P. striata was positive; at 60 days after sowing, it was neutral as the populations in treatments with single and combined inoculation were at par; and at harvest, it was negative The population of P. striata was higher at flowering stage as compared to 20 days after sowing and at harvest.  相似文献   
28.
The oral bioavailability of vasicine (1) was investigated in hard gelatin capsules of lyophilized Vasa Swaras (aqueous extract of Adhatoda vasica Nees.,Fam.: Acanthaceae) The rat pharmacokinetic profile of lyophilized Vasa Swaras, Vasa Swaras, vasicine (1) (chief marker compounds of A. vasica) and a marketed capsule formulation of A. vasica were compared. Vasicine (1) was found to be more orally bioavailable from lyophilized Vasa Swaras, with an overall minor conversion to vasicinone (2).  相似文献   
29.
30.
Screening of pea germplasm for resistance to powdery mildew   总被引:1,自引:0,他引:1  
Powdery mildew caused by Erysiphe pisi DC results heavy losses in the yield and quality of pods and seeds of pea crop. Germplasm comprising 701 accessions of garden and field pea originating from 60 countries were screened for powdery mildew resistance under natural epiphytotic conditions and 64 accessions found resistant in field screening for 2?years at one location were further screened both in field at two locations and artificially in laboratory to four isolates. The information was also obtained on the amount of genetic diversity and agronomic superiority in resistant accessions. Fifty-seven accessions showed resistant reaction for 3 consecutive years in field screening but only 14 accessions originating from 10 countries showed resistant reaction in laboratory screening against the four most prevalent isolates of E. pisi collected from different places in the area of experiment. Germplasm lines showed both complete and incomplete levels of resistance and variable reactions to different isolates. There was sufficient genetic diversity and agronomic superiority in the resistant accessions e.g. EC598655, EC598878, EC598704, IC278261, and IC218988, which may serve as useful genetic material to plant breeders for breeding pea varieties for powdery mildew resistance and high yield.  相似文献   
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