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2.
Natarajan Balakrishnan 《Communications in Soil Science and Plant Analysis》2016,47(11):1357-1371
Greenhouse experiment was conducted to assess the iron (Fe) and zinc (Zn) fractionation patterns in soils of arbuscular mycorrhizal (AM) fungus-inoculated and uninoculated maize plants fertilized with varying levels of Fe and Zn. Soil samples were collected for Fe and Zn fractions and available Fe, Zn and phosphorus (P) contents besides organic and biomass carbon (BMC), soil enzymes and glomalin. Major portion of Fe and Zn fractionations was found to occur in the residual form. Mycorrhizal symbiosis increased the organically bound forms of Fe and Zn while reducing the crystalline oxide, residual Fe and Zn fractions, indicating the transformation of unavailable forms into available forms. Soil enzymes, viz. dehydrogenase and acid phosphatase activities in M+ soils, were significantly higher than M? soil consistently. Overall, the data suggest that mycorrhizal symbiosis enhanced the availability of Fe and Zn as a result of preferential fractionation and biochemical changes that may alleviate micronutrient deficiencies in calcareous soil.Abbreviations: AM: arbuscular mycorrhiza; Fe: Iron; Zn: Zinc; P: Phosphorous; Amox-Zn: amorphous oxide bound zinc; Cryox-Zn: crystalline oxide bound zinc; DAS: days after sowing; DTPA: diethylene Triamine Penta Acetic Acid; MnO2-Zn: manganese oxide bound zinc; OC-Zn: organically bound zinc; WSEX: water soluble plus exchangeable zinc; MnO2 Fe: manganese oxide bound iron; OC-Fe: Organically bound iron; WSEX Fe: water soluble plus exchangeable iron. 相似文献
3.
Intercropping of Corn with Soybean and Lupin for Silage: Effect of Seeding Date on Yield and Quality
B. Prithiviraj K. Carruthers Q. Fe D. Cloutier R. C. Martin D. L. Smith 《Journal of Agronomy and Crop Science》2000,185(2):129-136
Intercropping of corn with legumes is an alternative to corn monocropping and has a number of advantages, for example, lower levels of inputs, lower costs of production and better silage quality than the monocrop system. An experiment was carried out at two sites in 1993 and 1994 to investigate the effects of seeding date (simultaneous with corn or 3 weeks later) and number of rows of large‐seeded legumes (one or two) seeded between the corn rows. The intercrop plots received 90 kg ha?1 less nitrogen fertilizer than the monocrop plots, which received 180 kg ha?1. Silage yields were sometimes decreased by the simultaneous seeding of corn and large‐seeded legumes. Protein content and concentration were not affected by most treatments and provided reasonable quality silage, despite a reduction in the amount of nitrogen fertilizer used. 相似文献
4.
K. Yore B. DiGangi M. Brewer N. Balakrishnan E.B. Breitschwerdt M. Lappin 《Veterinary parasitology》2014,199(3-4):225-229
Several Bartonella spp. associated with fleas can induce a variety of clinical syndromes in both dogs and humans. However, few studies have investigated the prevalence of Bartonella in the blood of dogs and their fleas. The objectives of this study were to determine the genera of fleas infesting shelter dogs in Florida, the prevalence of Bartonella spp. within the fleas, and the prevalence of Bartonella spp. within the blood of healthy dogs from which the fleas were collected. Fleas, serum, and EDTA-anti-coagulated whole blood were collected from 80 healthy dogs, and total DNA was extracted for PCR amplification of Bartonella spp. The genera of fleas infesting 43 of the dogs were determined phenotypically. PCR amplicons from blood and flea pools were sequenced to confirm the Bartonella species. Amplicons for which sequencing revealed homology to Bartonella vinsonii subsp. berkhoffii (Bvb) underwent specific genotyping by targeting the 16S–23S intergenic spacer region.A total of 220 fleas were collected from 80 dogs and pooled by genus (43 dogs) and flea species. Bartonella spp. DNA was amplified from 14 of 80 dog blood samples (17.5%) and from 9 of 80 pooled fleas (11.3%). B. vinsonii subsp. berkhoffii DNA was amplified from nine dogs and five of the flea pools. Bartonella rochalimae (Br) DNA was amplified from six dogs and two flea pools. One of 14 dogs was co-infected with Bvb and Br. The dog was infested with Pulex spp. fleas containing Br DNA and a single Ctenocephalides felis flea. Of the Bvb bacteremic dogs, five and four were infected with genotypes II and I, respectively. Of the Bvb PCR positive flea pools, three were Bvb genotype II and two were Bvb genotype I.Amplification of Bvb DNA from Pulex spp. collected from domestic dogs, suggests that Pulex fleas may be a vector for dogs and a source for zoonotic transfer of this pathogen from dogs to people. The findings of this study provide evidence to support the hypothesis that flea-infested dogs may be a reservoir host for Bvb and Br and that ectoparasite control is an important component of shelter intake protocols. 相似文献
5.
R. M. M. S. Thilakarathna Y. A. Papadopoulos S. A. E. Fillmore B. Prithiviraj 《Journal of Agronomy and Crop Science》2012,198(4):295-303
Red clover cultivars, including diploid and tetraploid, are commonly used in legume‐based pasture mixtures. However, information on nodulation under different starter N regimens is limited. We hypothesized that there is genetic variability among different red clover cultivars for nodulation. A root hair deformation assay was conducted using three diploid (AC Christie, Tapani and CRS15) and three tetraploid (Tempus, CRS18 and CRS39) red clover cultivars by inoculating them with Rhizobium leguminosarum biovar trifolii. Nodulation and morphological characteristics of two selected red clover cultivars, AC Christie and Tempus, were determined under five starter N concentrations (0, 0.2, 0.4, 0.8 and 1.6 mg per plant). Inoculation with rhizobia increased root hair deformation with significant interaction across cultivars. Nodulation was delayed under high starter N concentrations, and genotypic differences were evident for days‐to‐nodule initiation. There was a positive quadratic response to starter N for AC Christie and a negative quadratic response for Tempus for nodulation. Tempus had more active nodules (92 %) than AC Christie (73 %). The genetic variability of red clover cultivars should be considered in N fixation studies and their response to availability of initial N. 相似文献
6.
Algal bioassay studies on the effect of F concentrations on diatoms Nitzschia palea (freshwater) and Amphora coffeaeformis (brackishwater) were conducted in the laboratory. Significant enhancement of growth occurred in N. palea at F concentrations between 10 and 110 mg L?1. In A. coffeaeformis statistically significant stimulation occurred at 70 mg L?1 F and above 90 mg L?1 F the growth declined. The results indicate that the diatom N. palea and A. coffeaeformis can tolerate high F concentration. 相似文献
7.
B. Prithiviraj A. Vikram A.C. Kushalappa V. Yaylayan 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(4):371-377
The volatile metabolites of the headspace gas of onion bulbs inoculated with three different pathogens, Erwinia carotovora ssp. carotovora, Fusarium oxysporum and Botrytis allii, were profiled using gas chromatography/mass spectrometry. Differences in the number and amount of volatile metabolites were observed. Two hundred and fifty three volatile metabolites were detected in bulbs inoculated with three pathogens or sterile distilled water. On day three, 202 volatile metabolites were observed, compared to 166 on day six. Of the 253 compounds, however, only 59 occurred relatively consistently over replications, of which 25 compounds were specific to one or more pathogens, including 10 that were unique to a pathogen. Metabolites such as 1-Oxa-4,6-diazacyclooctane-5-thione and 4-mercapto-3-(methylthio)--(thio-lactone)-crotonic acid were exclusive to onions inoculated with F. oxysporum. Acetone, acetic acid-hydrazide, propylcarbamate, 1-bromo-1-propene, thiirane, 1-(methylthio)-E-1-propene and 1-ethenyl-4-ethyl-benzene were specific to B. allii. 3-bromo-furan was specific to E. carotovora ssp. carotovora. Sterile water-inoculated bulbs produced 3,3-dioxy-1,2-propanediol-tetranitrate. Highest amount of sulfurs was found in pathogen-inoculated, while highest amounts of terpenes, aromatics and aliphatics were found in sterile distilled water-inoculated bulbs. The possible use of these differences in the volatile metabolites for detecting and discriminating diseases of onion in storage is discussed. 相似文献
8.
S. Jeyakumar Arun Kumar DeA. Kundu Kuntola RoyJai Sunder M.S. KunduM. Balakrishnan Subhash ChandS.K. Zamir Ahmed 《Livestock Science》2013,152(1):79-87
Assessing the health of the testes in domestic animals is an important aspect of the breeding soundness examination and selection. The aim of the present study was to develop a simple method for scanning and to establish ultrasonographically the gross anatomic structures of the goat testes. Six adult male goats were examined to study the sonographic appearance of normal testes and epididymides using a water bath based ultrasound scanning technique. The ultrasonographic examinations were done using a 5–9 MHz/60 mm (7.5 MHz) linear-array transducer and a B-mode scanner. The ultrasonographic examination was performed in goats after standardizing the procedure on six testes collected from slaughter house. Results showed that in live goats when the probe was placed directly over the scrotum it gave distorted and unclear image. In water bath method the entire scrotum was dipped into a container filled with water and linear probe was used to observe the sonographic features of the testis. Each testis was viewed vertically, resulting in longitudinal image which was frozen, measured and printed through a thermal printer. The results of the ultrasonogram revealed that the testicular parenchyma was homogenous and moderately echogenic throughout. The diameter (mean±se) of the right and left testes was 4.47±0.14 and 4.42±0.07 cm respectively and no significant difference was observed between the testes. The mediastinum testis was a 1.50±0.22 cm wide linear structure of greater echogenicity than the testicular parenchyma when viewed in the transverse plane and nearly circular echogenic “spot” in the midline of the testis when viewed horizontally. The head and tail of the epididymides were easily identified on all the testes, but the epididymal body and ductus deferens were difficult to identify consistently. The tail of the epididymis was easily identified on the distal end of the testis with sonolucent tubules and appeared sonographically as a ‘peaked cap’ upon the testicular parenchyma. The diameter (mean±se) of the tail of right and left epididymis was 2.11±0.18 and 1.92±0.06 cm and no significant difference was observed between epididymides. The vascular pampiniform plexus (1.42±0.18 cm) was easily identified on the proximal end of the testes. The tunics of the testes appeared as a bright echogenic line. Inter-testicular septum appeared between testes as a hyperechoic line. It is concluded that ultrasonography permits a noninvasive evaluation of the internal structure of the scrotum and testes and water bath based sonographic examination may prove to be a valuable simple diagnostic methodology for evaluating physiopathologic conditions of goat testes and can be employed as a routine investigative method during breeding soundness and clinical examination. 相似文献
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10.
Vrinda Ramakrishnan Bijinu Balakrishnan Amit Kumar Rai Bhaskar Narayan Prakash M Halami 《International Aquatic Research》2012,4(1):1-14
Enterococci are widely distributed in the environment ranging from foods to humans and are gaining industrial importance due to their technological traits. In the present study, enterococci (Enterococcus faecium NCIM5363 (EF-63) and Enterococcus durans NCIM5427 (ED-27)) which are native to fish processing waste with an ability to produce lipase, protease and enterocin concomitantly were characterised. Lipase assay was performed by titrimetry and protease activity and was estimated using haemoglobin and casein as substrates in the presence of buffers at acidic, basic and neutral pH. Furthermore, enterocin produced by the isolates was characterised. Enterocin was also checked for its stability at different pH, temperature and proteolytic enzymes. Lipase production was found to be 22 and 10 U/ml in the absence of tributryin and increased to 40 and 24 U/ml in its presence for EF-63 and ED-27, respectively, indicating that the lipase produced is substrate dependent. Protease production was confirmed by protease assay, and the protease produced showed more affinity towards the acidic substrate. Enterocin produced was stable at low pH (2 to 3) and high temperature (121°C, 15 min) and had a molecular weight of approximately 6 kDa. It exhibited antibacterial activity against both Gram-positive and Gram-negative food-borne pathogens. Proteinase K inactivated enterocin completely, whereas trypsin did not. Novelty of this work lies in the immense industrial importance these cultures hold as they are capable of producing lipase, protease and enterocin apart from being useful in recovering proteins and lipids from fish processing wastes. 相似文献