Some observations on the zoospores from the zoosporangia ofPlasmodiophora brassicae Woron

European Journal of Plant Pathology - Het onderzoek had ten dcel het gedrag van de zoösporen uit de zoösporangia vanPlasmodiophora brassicae na te gaan. Aangetaste worteltjes van jonge...     

Over de vatbaarheid van niet-kruisbloemige planten voor het zoösporangium-stadium vanPlasmodiophora brassicae Woron

Samenvatting en bespreking Een vijftiental plantensoorten werd onderzocht op vatbaarheid voor het zoösporangium-stadium vanP. brassicae. Hiervan werdenTrifolium pratense, Reseda odorata enLolium perenne in zeer geringe mate, enPapaver rhoeas iets sterker aangetast. De mate van aantasting van deze laatste was echter nog aanzienlijk minder dan van als vergelijkingsobject gebruikte bloemkoolplantjes. Gezien deze resultaten is het niet waarschijnlijk, dat niet-cruciferen enigermate kunnen bijdragen tot de instandhouding of vermeerdering van de schimmel bij afwezigheid van kruisbloemigen. Evenmin is er reden te veronderstellen, dat niet-cruciferen als vangplanten voor het uitroeien van de rustsporen van groot practisch belang kunnen zijn.Summary Webb's (1949) discovery of zoosporangia ofP. brassicae in non-crucifers raises the question of further means of multiplication and survival in the soil (MacFarlane, 1952). Perhaps the fungus can maintain itself in successive generations of zoosporangia in root hairs of these plants. From there it might in turn infect crucifers and produce a fresh crop of resting spores. This must be kept in mind when considering the possibility of eradicating the fungus from the soil by growing non-crucifers which stimulate the resting spores to germinate. If survival in root hairs were important, plants for this purpose would need to resist the zoosporangial stage as well as stimulate spore germination.In the present study a number of non-crucifers was tested for susceptibility to the zoosporangial stage by a method already described (Kole, 1955). In addition, the rate of infection of susceptible non-crucifers was compared with that of cabbage grown under the same conditions. Of seven non-crucifers, not tested before, onlyTrifolium pratense became infected.MacFaralane's findings of non-cruciferous hosts were confirmed forPapaver rhoeas, Reseda odorata andLolium perenne (Table 1). In all the susceptible non-crucifers exceptPapaver rhoeas, infection was very sligth. There were more infections onPapaver rhoeas than on the other non-crucifers but fewer than on cabbage, which was heavily infected. On the basis of these results it is not thought that the occurrence of non-cruciferous hosts ofP. brassicae will generally be of great practical importance.     

Resting-spore germination inSynchytrium endobioticum

The resting spores ofS. endobioticum function as a prosorus in germination. The contents of the resting spore are extruded as a vesicle. Within this vesicle one single sporangium develops. Germinating resting spores resemble resting spores which have been parasitized by certain fungi, but it is obvious from several facts presented that no parasites were present. On the basis of the mode of germination described,S. endobioticum should be transferred from the subgenusMesochytrium to the subgenusMicrosynchytrium.     

Evaluation of interferon gamma (IFN-γ) of <Emphasis Type="Italic">Labeo rohita</Emphasis> as an immunomodulator: in vitro expression model

Interferon gamma (IFN-γ) or type II interferon is a cytokine that is critical for innate and adaptive immunity against viral and some bacterial and protozoal infections. The importance of IFN-γ in the immune system lies in its ability to inhibit viral replication directly and most importantly from its immunomodulatory effects. Previously, we successfully co-administered IFN-γ along with GAPDH gene of Edwardsiella tarda as bicistronic DNA vaccine in Labeo rohita. In order to ascertain the individual role of IFN-γ, the present study involves cloning and expression of 552-bp IFN-γ open-reading frame (ORF) of L. rohita in striped snakehead (SSN-1) cell line using eukaryotic expression vector system (pQE-TriSystem) followed by transfection in peripheral blood lymphocytes (PBMCs) to evaluate its immunomodulatory ability in comparison to polyinosinic-polycytidylic acid (Poly I:C)-treated PBMCs. The 18.7-kDa protein, expressed in the pQE-IFNγ-transfected SSN-1 cells, reacted with anti-His antibody in Western blot confirming it to be recombinant IFN-γ, whereas the relative expression of IFN-γ, iNOS, Mx, and IL-1β genes in PBMCs was quantified at 24 h and 48 h post treatment by qPCR. The comparative kinetics of all four genes showed significantly (p?<?0.05) high upregulation pattern in both pQE-IFNγ-transfected cell group and Poly I:C-treated cell group demonstrating recombinant IFN-γ as an equally efficient inducer like Poly I:C. Thus, our in vitro experiment results highlight the immunomodulatory potential of recombinant IFN-γ as an analogue to synthetic Poly I:C which warranted future studies to further explore the potential of recombinant IFN-γ as an effective vaccine adjuvant against different microbial invasion.     

Protein and oil composition predictions of single soybeans by transmission Raman spectroscopy

The soybean industry requires rapid, accurate, and precise technologies for the analyses of seed/grain constituents. While the current gold standard for nondestructive quantification of economically and nutritionally important soybean components is near-infrared spectroscopy (NIRS), emerging technology may provide viable alternatives and lead to next generation instrumentation for grain compositional analysis. In principle, Raman spectroscopy provides the necessary chemical information to generate models for predicting the concentration of soybean constituents. In this communication, we explore the use of transmission Raman spectroscopy (TRS) for nondestructive soybean measurements. We show that TRS uses the light scattering properties of soybeans to effectively homogenize the heterogeneous bulk of a soybean for representative sampling. Working with over 1000 individual intact soybean seeds, we developed a simple partial least-squares model for predicting oil and protein content nondestructively. We find TRS to have a root-mean-standard error of prediction (RMSEP) of 0.89% for oil measurements and 0.92% for protein measurements. In both calibration and validation sets, the predicative capabilities of the model were similar to the error in the reference methods.     

Waarnemingen over het gedrag van zoösporen uit de zoösporangia vanOlpidium brassicae (wor.) dang

Summary The zoosporangial zoospores ofOlpidium brassicae are uniflagellate (fig. 1). Observations with a phase contrast microscope on living zoospores in watermounts showed that biflagellate zoospores resulted from zoospore fusion. Further, specimens were found with more than two flagella (fig. 2 and 3). As at zoospore discharge only uniflagellate zoospores occur, it may be, assumed that zoospores with more than two flagella are also the result of zoospore fusion. As there may be an analogy betweenO. brassicae andO. viciae,Kusano's explanation of the occurrence of compound zoospores with more than two flagella is discussed.     

Elektronenmicroscopische waarnemingen over de zoösporen uit de zomersporangia vanSynchytrium endobioticum (Schilb.) Perc

Summary Electron microscope observations on the soral zoospores ofSynchytrium endobioticum revealed, besides nuclear substance, the presence of a crateriform cavity in the zoospore body. Probably this cavity corresponds with the vacuole which contains oil in the living zoospore. The flagella are cylindrical and they have a whiplash tip. Faint longitudinal striations can just be detected in some of the flagella. A slight terminal swelling on the end of the whiplash is occasionally found. Several flagella, showed fibrillar disintegration. Making elevent fibres in all, there are two long central strands and nine shorter peripheral strads. A fine line running along the centre of some fibres indicates that probably each fibre contains two subfibres.     

Persistence and metabolism of imidacloprid in different soils of West Bengal

A laboratory experiment was performed to study the persistence of imidacloprid from two formulations (Confidor 200 g litre-1 SL and Gaucho 700 g kg-1 WS), and its metabolism in three different soils (Gangetic alluvial soil of Kalyani, lateritic soil of Jhargram and coastal alkaline soil of Canning) of West Bengal following application at 0.5 kg and 1.0 kg AIha-1. Dissipation of imidacloprid in soil followed first-order kinetics and DT50 values ranged from 28.7 to 47.8 days. The shortest half-lives (28.7 and 35.8 days) were observed in the lateritic soil of Jhargram for both liquid and powder formulations. The formation of two metabolites of imidacloprid, imidacloprid-urea and imidacloprid-olefin, was first detected on day 30 of degradation at 28 (+/- 1) degrees C in all three soils.