Isozyme Banding Pattern and Estimation of Genetic Diversity among Guinea Grass Germplasm     

Abha Jain  A. K. Roy  P. Kaushal  D. R. Malaviya  S. N. Zadoo 《Genetic Resources and Crop Evolution》2006,53(2):339-347

Isozyme banding pattern was studied in Guinea grass (Panicum maximum Jacq.), a widely cultivated grass having good fodder value. Similarity among 63 accessions collected from diverse sources was worked out using five enzyme systems (SOD, GOT, ACP, Esterase and Peroxidase) following horizontal starch gel electrophoresis. Biochemical markers such as isozymes are useful supplements in identifying the genetic variation present in any crop. A total of 35 clear and unambiguous bands were used for analysis of which 8 bands were monomorphic. Polymorphism exhibited by 27 bands from all five enzyme systems indicate presence of considerable diversity in this species. The dendrogram generated after UPGMA and SAHN cluster analysis using Jaccard genetic distance showed that 63 accessions from diverse geographical locations could be grouped in three main clusters, of which two could further be divided into sub-clusters. Although the clusters comprised members from different locations, most of the accessions from similar geographical locations tended to cluster in same group.  相似文献   

Determination of a chemical basis of air-pollution stress in wood of mature white pine trees in the susceptive forest ecosystems     

S. N. Pathak  D. V. Love  D. N. Roy 《Water, air, and soil pollution》1986,31(1-2):385-392

This paper describes a pilot investigation dealing with changes in chemical composition of wood in pollution-stressed white pine trees, taken from two forested ecosystems of Southern Ontario, Canada. The implications of this research lie in a much needed search for a potential bloindicator of a pre-decline, incipient-stress induced (and/or contributed by) the air-pollutants.  相似文献   

δ34S variations in vegetation and soil exposed to intense biogenic sulphide emissions near Paige mountain,N.W.T., Canada     

H. Roy Krouse  Robert O. Van Everdingen 《Water, air, and soil pollution》1984,23(1):61-67

Sulphur isotope abundances demonstrate that natural emissions of biogenic H₂S and its oxidation products from springs near Paige Mountain, N.W.T., Canada, can be incorporated into surrounding soil and vegetation. δ³⁴S values as low as ? 33‰ for soil and vegetation are the result of dominant uptake of biogenic atmospheric compounds. In contrast, vegetation on a gypsum outcrop remote from the springs, has δ³⁴S values as high as + 26‰ indicating nearly exclusive derivation of S from the soil. Near the springs, soil with vegetative cover is less depleted in ³⁴S than soil lacking cover. Lower needles on a Black Spruce were found to be less depleted in ³⁴S than the upper needles. These observations suggest that upper foliage exerts a canopy effect on lower foliage and in turn, interception by vegetation reduces the flux of atmospheric S compounds to the soil. Clearly, natural emissions of S compounds can interfere in studies of long range transport of industrial emissions; S isotope analyses might identify such interferences and reduce the chance of misinterpretation.  相似文献   

Contamination environnementale par les métaux et maladie de Parkinson     

J. Zayed  P. André  J. C. Panisset  S. Ducic  G. Campanella  M. Roy  G. Kennedy  C. Delisle 《Water, air, and soil pollution》1990,49(1-2):197-203

Parkinson's disease (PD) has been proposed to result from the interaction of aging and environment in susceptible individuals. The prevalence of PD in Quebec was 84 per 100 000 in 1985. The regional variation observed has been linked with several environmental factors. We intended to verify the existence of a relation between the development of PD with exposure to 3 metal pollutants: Fe, Mn, and Al. The choice of these metals rests on their potential presence in the environment caused by the industrial activity in the region studied, and on the fact that it theoretically favors the prevalence of the illness. Environmental exposure to these metals and the resulting risks were evaluated using red spruce as a bio-indicator. The metal concentrations in tree rings were determined by neutron activation analysis. These concentrations permitted a temporal estimation of contamination in each of the territories studied, from 1938 to 1987. The risk of environmental exposure was assumed to be proportional to the concentration of the metal. The calculated risks combined with the history of residence allowed a comparison between parkinsonians and controls. It appeared that environmental exposure to the metals was not significantly different between those two groups.  相似文献   

Dynamics of microbial biomass and nitrogen supply during primary succession on blastfurnace slag dumps in dry tropics     

A Roy K.P Singh 《Soil biology & biochemistry》2003,35(3):365-372

This paper reports the role of microbial biomass in the establishment of N pools in the substratum during primary succession (till 40-year age) in Blastfurnace Slag Dumps, an anthropogenically created land form in the tropics. Initially in the depressions in the slag dumps fine soil particles (silt+clay) accumulate, retaining moisture therein, and providing microsites for the accumulation of microbial biomass. In all sites microbial biomass showed distinct seasonality, with summer-peak and rainy season-low standing crops. During the summer season microbial biomass C ranged from 18.6 μg g⁻¹ in the 1-year old site to ca. 235 μg g⁻¹ in the 40-year old site; correspondingly, microbial biomass N ranged from 1.22 to 40 μg g⁻¹. On sites 2.5-years of age and younger, the microbial biomass N content accounted for more than 50% of the organic N in the soil, whereas the proportion of microbial biomass N was ca. 7% of organic N in 40-year old site. The strong correlation between microbial biomass and total N in soil indicated a significant role of microbes in the build-up of nitrogen during the initial stages of succession in the slag dumps. Though the organic N pool in the soil was low (594 mg kg⁻¹) even after 40 years of succession, the available N (NH₄-N and NO₃-N) contents in the soil were generally high through the entire age series (ca. 16-32 μg g⁻¹) during the rainy season (which supports active growth of the herbaceous community). The high mineral-N status on the slag dump was related with high N-mineralization rates, particularly in the young sites (20.6 and 13.9 μg g⁻¹ month⁻¹ at 1 and 2.5-year age). We suggest that along with the abiotic factors having strong effect on ecosystem functioning, the microbial biomass, an important biotic factor, shows considerable influence on soil nutrient build-up during early stages of primary succession on the slag dumps. The microbial biomass dynamics initiates biotic control in developing slag dumps ecosystem through its effect on nitrogen pools and availability.  相似文献   

Acute and sublethal toxicity of tributyltin oxide (tbto) and its putative environmental product,tributyltin sulfide (tbts) to zoeal mud crabs,rhithropanopeus harrisii     

Roy Laughlin  W. French  H. E. Guard 《Water, air, and soil pollution》1983,20(1):69-79

Mud crab larvae, Rhithropanopeus harrisii were exposed to tributyltin oxide, (TBTO) (0.5, 1, 5, 10, 15, or 25 μg l^?1) or tributyltin sulfide (TBTS) (0.5, 1, 5, 20, 30, or 50 μg l^?1). Differential survival was observed in TBTO concentrations equal to or greater than 10 gg l^?1 and in TBTS concentrations equal to or greater than 20 μg l^?1 Growth and development rate were assessed as sublethal indices of stress. Of the two, development rate was more sensitive. All groups exposed to either compound had slower development rates than controls. Growth of the larvae, as shown by weight gain, was slightly increased in low exposures (a hormetic response) and decreased significantly in higher concentrations. The mean weight of the 50 μg l^?1 TBTS group showed the largest decrease, to 57% of the control. The hormesis response was further examined by measuring daily growth of the zoeae. All groups exposed to tributyltin compounds showed an initial growth lag. The hormesis response occurred in the fourth zoeal stage or megalops. While R. harrisii is relatively tolerant to the acute toxicity of tributyltin compounds compared to other marine crustaceans tested, sublethal responses occur in very low concentrations. This points to the need for analyses to characterize tributyltin environmental concentrations.  相似文献   

Adherence of Actinobacillus pleuropneumoniae to porcine tracheal epithelial cells and frozen lung sections   总被引：3，自引：0，他引：3  

M Jacques  M Bélanger  G Roy  B Foiry 《Veterinary microbiology》1991,27(2):133-143

The ability of 23 different Actinobacillus pleuropneumoniae isolates to adhere in vitro to porcine tracheal epithelial cells and to porcine frozen lung sections was examined. It was found that A. pleuropneumoniae adhered poorly to isolated tracheal epithelial cells. On the other hand, A. pleuropneumoniae adhered to frozen lung sections and marked variations were observed between and within serotypes. Adherence to lung sections did not seem related to the hemagglutinating activity of the isolate. Two noncapsulated variants adhered to lung sections in greater numbers than their capsulated parent strains. Adherence to lung sections was not inhibited by the extracellular matrix components tested namely, laminin, fibronectin, and collagen, but was inhibited by homologous serotype-specific antiserum. The data indicated that the A. pleuropneumoniae isolates tested possess the ability to adhere to porcine lung tissue, a property which did not seem to be related to the serotype and did not seem to involve the capsular material or the hemagglutinins of the isolates.  相似文献   

A COMPARISON OF RADIOGRAPHY, COMPUTED TOMOGRAPHY, AND MAGNETIC RESONANCE IMAGING FOR THE DIAGNOSIS OF PALMAR PROCESS FRACTURES IN FOALS     

Andris J.  Kaneps  D.V.M.  Ph.D  Philip D.  Koblik  D.V.M.  M.S.  Dominique M.  Freeman  Ph.D.†  Roy R.  Pool  D.V.M.  Ph.D.‡  Timothy R.  O'Brien  D.V.M.  Ph.D. 《Veterinary radiology & ultrasound》1995,36(6):467-477

The relative sensitivity of radiography, computed tomography, and magnetic resonance imaging for detecting palmar process fractures of the distal phalanx in foals was determined and the imaging findings were compared with histomorphologic evaluations of the palmar processes. Compared to radiography, computed tomography and magnetic resonance imaging did not improve the sensitivity for detection of palmar process fractures. Statistical agreement for palmar process fracture diagnosis was excellent among the three imaging modalities. Histomorphologic evaluations were more sensitive for diagnosis of palmar process fracture than any of the imaging modalities. Three-dimensional image reconstructions and volume measurements of distal phalanges and palmar process fracture fragments from computed tomography studies provided more complete anatomical information than radiography. Magnetic resonance imaging confirmed that the deep digital flexor tendon insertion on the distal phalanx is immediately axial to the site where palmar process fractures occur, and differentiated cartilage, bone, and soft tissue structures of the hoof.  相似文献   

Latency of equine herpesvirus 4 (equine rhinopneumonitis virus)     

G F Browning  D M Bulach  N Ficorilli  E A Roy  B H Thorp  M J Studdert 《The Veterinary record》1988,123(20):518-519

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Molecular and genetic comparisons of two serotypes of epizootic hemorrhagic disease of deer virus     

J Kusari  P Roy 《American journal of veterinary research》1986,47(8):1713-1717

The virus-specific double-stranded genome RNA of 2 serotypes of epizootic hemorrhagic disease of deer virus (EHDV) was evaluated by use of coelectrophoresis in polyacrylamide and agarose gel systems. The molecular weights of virion RNA segments were 0.32 to 2.57 X 10(6) for EHDV-1 and 0.33 to 2.54 X 10(6) for EHDV-2. Seven of 10 double-stranded RNA segments of the 2 serotypes had different electrophoretic mobilities in the polyacrylamide-gel electrophoresis system. Although the individual RNA segments of each serotype contained unique RNA sequences determined on the basis of 2-dimensional polyacrylamide-gel electrophoresis analysis of oligonucleotides, the corresponding segments of the 2 serotypes were found to be comparable and at least 1 pair of RNA segment was almost identical. Virus-specific polypeptides for the 2 serotypes were compared by use of gel electrophoresis. Eleven polypeptides were detected for EHDV-1 and 10 for EHDV-2. Six corresponding polypeptides of these 2 serotypes had different electrophoretic mobilities, indicating that these corresponding polypeptides differ in their molecular weights. A genetic relationship was not determined between the 2 EHDV serogroups and the blue-tongue serogroup viruses, using oligonucleotides mapping.  相似文献