Pod wart disease of peanuts

Peanut pod wart, a relatively new disease to peanut culture, was first reported in Israel in 1988 attacking peanut plants and causing dark warts on the pod. The causal agents are variousStreptomyces spp. Scanning electron microscopy showed a significant difference between healthy and diseased tissues of the exocarp and mesocarp layers of the pod; there were no effects on the endocarp layer. The mesocarp cells of infected tissue were smaller and more compressed than those of healthy tissue. In most cases two cells under the peak of the wart were extremely large and the cells growing from them toward the surface were uneven, forming the shape of a fan. The pathogen could be isolated from the soil and rhizosphere, but in the pod it was found only in the waited tissue. The microorganisms isolated from the warts belong to different groups ofStreptomyces spp.; subsequent pathogenicity tests proved their virulence to a limited host range. In potato, these isolates ofStreptomyces spp. caused deep pitted scab; in peanuts they caused warts. Peanut seeds which developed in infected pods were free of the pathogen if the shell was undamaged. However, the pathogen is surface seedborne, and contaminated seeds during the mechanical cracking process.     

Ecophysiological approach to competition between Amaranthus chlorostachys and sunflower (Helianthus annuus) under drought stress

Interspecific competition between Amaranthus chlorostachys Willd. and sunflower (Helianthus annuus L., NSH-33 hybrid) in pure and mixed stands of the same density was studied in small plot experiments to elucidate the ecophysiological responses of the competing species under drought stress. When grown in a mixed stand the extremely low intensity of transpiration in A. chlorostachys resulted in a difference in the water use efficiency (WUE) values of net photosynthesis between the two species. The values were higher in A. chlorostachys. Interspecific competition reduced the total individual plant weight to a greater extent in sunflower than in the weed species by the end of the growing season. Reproductive effort was higher in A. chlorostachys than sunflower and, in our opinion, best reflects the outcome of competi-tion. On the basis of the correlation between WUE and reproductive allocation, reproduc-tive effort in sunflower and A. chlorostachys in both intra- and interspecific competition is determined by the value of WUE, which latter is also of prime importance in drought stress tolerance. Approche écophysiologique de la compétition entre Amaranthus chlorostachys et le tournesol (Helianthus annuus) en condition de stress hydrique La compétition interspécifique entre Amaranthus chlorostachys Willd. et le tournesol (Helianthus annuus L. hybride NSH 33) dans des stations mixtes et simples de densité de plantes identiques (espacement de 35 × 35 cm) a étéétudié dans une expérimentation de plein champ en petites parcelles. Notre but était d'éclairer les réponses écophysiologiques des espèces en compétition (compétition inter et intra spécifique) sous stress hydrique et de mettre en lumière les corrélations entre les processus ecophysiologiques adéquats et les paramètres de la production de biomasse quan-tifiant le résultat de la compétition. Quand la culture a été faite dans des stations mixtes, la très faible intensité de transpiration chez A. chlorostachys a abouti à une différence ultérieure entre les valeurs de l'efficacité de l'utilisation (WVE) de l'eau dans la photosynthèse chez les 2 espèces: celle-ci était plus élevée chez A. chlorostachys. La compétition interspécifique a réduit le poids total des plantes individuelles de faon plus importante chez le tournesol que chez la mauvaise herbe à la fin de la saison de croissance. L'importance de la reproduction, qui à notre avis reflète le mieux le résultat de la compétition exprimée dans une aptitude à se reproduire plus élevée chez A. chlorostachys que chez le tournesol. Sur la base de la corrélation entre WVE et l'aptitude à se reproduire, l'importance de la reproduction chez le tournesol et A. chlorostachysà la fois en compétition intra et inter spécifique est déterminée par la valeur de WVE, qui est aussi de première importance dans la tolérance au stress hydrique. Ökophysiologische Untersuchung der Konkurrenz zwischen Amaranthus chlorostachys und Sonnenblume (Helianthus annuus) unter Trockenstreβ Die Konkurrenz zwischen Amaranthus chlorostachys Willd. und der Sonnenblume (Helianthus annuus L., ‘NSH-33’) in Rein- und Mischbeständen gleicher Pflanzendichte (Abstand 35 cm) wurde in Feldversuchen auf kleinen Parzellen untersucht. Die ökophysiologische Reaktion der konkurrierenden Arten (bei intra- und interspezifischer Konkurrenz) unter Trockenstreß, die Beziehungen zwischen den relevanten ökophysiologischen Prozessen und die Biomasseproduktion unter dem Einfluß der Konkurrenz sollten bestimmt werden. In Mischbeständen führte die extrem niedrige Intensität der Transpiration von Amaranthus chlorostachys zu einer noch verstärkten Differenz zwischen den Werten der Wasserausnutzung (WUE) der Netto-Photosynthese der beiden Arten, die bei Amaranthus chlorostachys höher waren. Die interspezifische Konkurrenz verringerte die Einzelpflanzenmasse bei der Sonnenblume zum Ende der Vegetationsperiode stärker als beim Unkraut. Der Repro-duktions-Aufwand, der unserer Meinung nach die Konkurrenzwirkung am besten widerspiegelt, war bei Amaranthus chlorostachys höher als bei der Sonnenblume. Er wird bei beiden Arten sowohl bei intra- als auch interspezifischer Konkurrenz durch den Wert der WUE bestimmt, die auch für die Trockenstreß-Toleranz sehr wichtig ist.     

Epidemiology of feline leukaemia and feline immunodeficiency virus infections in the Czech Republic

Commercial serological sets were used for the examination of 727 cats kept in larger towns of the Czech Republic. FeLV antigen and antibodies to FIV were demonstrated in 96 (13.2%) and 42 (5.8%) of the animals, respectively. Seven (0.96%) animals were positive for both FeLV and FIV. Most of the FeLV and/or FIV positive patients were intact rambling males aged 1-4 years. Chronic gastrointestinal and respiratory diseases were found in 54.2% and 43.8% of the FeLV-positive patients, respectively. Chronic urinary tract diseases and generalized lymphadenopathy were found in 47.6% and 45.2% of the FIV-positive patients, respectively. The results of this first survey in the Czech Republic have shown prevalence values and clinical patterns similar to those reported formerly from other European countries.     

Biological Control of Bipolaris sorokiniana on Tall Fescue by Stenotrophomonas maltophilia Strain C3

ABSTRACT Stenotrophomonas maltophilia strain C3 was evaluated for control of leaf spot on tall fescue (Festuca arundinacea) caused by Bipolaris sorokiniana. In growth chamber experiments, C3 inhibited conidial germination on leaf surfaces and reduced lesion frequency and percent diseased leaf area compared with nontreated controls. The amount of leaf spot suppression was related to the C3 dose applied. The highest dose tested, 10(9) CFU/ml, prevented nearly all B. sorokiniana conidia from germinating on treated leaf surfaces and provided nearly complete suppression of lesion development. When colloidal chitin was added to C3 cell suspensions of 10(7) or 10(8) CFU/ml, biocontrol efficacy was significantly increased over C3 applied alone, whereas addition of chitin to a C3 cell suspension of 10(9) CFU/ml had no effect. In field experiments, application of C3 to tall fescue turf resulted in significant reductions in infection frequency and disease severity compared with nontreated controls. Strain C3 applied at 10(9) CFU/ml was more effective than C3 applied at 10(7) CFU/ml, and amendment of the lower dose with colloidal chitin enhanced its efficacy. Populations sizes of C3 established on foliage in a growth chamber and in the field were directly related to dose applied. Chitin amendments did not affect C3 population size.     

Examination of the pathogenesis of diabetic nephropathy in OLETF rats

We conducted protein loading to examine the progression and pathogenesis of diabetic nephropathy. For this experiment, male OLETF, LETO, F344 and BN rats were used. This experiment was performed on rats between 5 and 30 weeks of age. Examination parameters included body weight, food intake, oral glucose tolerance test (OGTT), urinary protein level (UP), urinary albumin level (UA), glomerular filtration rate (GFR), kidney weights, light microscopy (LM) and electron microscopy (EM). In the protein-loaded OLETF group, the UP level was markedly increased 20 weeks or more after birth. In OLETF control group, GFR were higher than those in other strains. Glomerular hypertrophy and kidney weights were markedly increased in protein-loaded groups in OLETF rats. Thirty weeks after birth, EM showed that the number of polyethyleneimine (PEI) of the glomerular basement membrane (GBM) in protein-loaded OLETF group was significantly decreased compared to that in control group. These changes in OLETF rats were more marked in the protein-loaded group than those in the control group. LM showed that the number of exudative lesions with fibrin-cap in the protein-loaded OLETF group was significantly increased than those in control group. In OLETF rats, protein loading caused deterioration of nephropathy at 30 weeks of age. Therefore, it was demonstrated that not only blood sugar control but also protein intake factors play important roles in the deterioration of nephropathy in OLETF rats.     

Effect of different daily doses of gizzerosine on the serum 1,25-dihydroxycholecalciferol concentration in laying hens

Five groups of laying hens were treated with different gizzerosine doses (0, 2.5; 5.0; 7.5; 10.0 mg/kg/body weight of gizzerosine) daily over a 21-day period to determine the serum concentrations of 1.25-dihydroxycholecalciferol (1,25(OH)2D), total calcium, inorganic phosphorus and magnesium. Blood samples were taken on days 7, 14, and 21 of the experiment. The concentration of 1,25(OH)2D remained unchanged after day 7 in the gizzerosine-treated birds compared to the control group. After 14 days, it was significantly lower in the birds receiving. gizzerosine, compared with the control group. On day 21, 1,25(OH2)D concentrations were also significantly decreased in all 4 gizzerosine-treated groups compared with the control hens. The serum total calcium, inorganic phosphorus and total magnesium concentrations varied significantly, but irregularly, during the period of the study.     

Failure of viral protein 3 of infectious bursal disease virus produced in prokaryotic and eukaryotic expression systems to protect chickens against the disease

In recent years, infectious bursal disease virus (IBDV) has become a serious economic problem as a result of the emergence of new and very virulent strains. Most of the antibodies produced against IBDV are for the structural proteins viral protein (VP) 2 (VP2) and VP3. The purpose of this study was to test the potential of recombinant VP3 to induce protective antibodies. The gene for VP3 was isolated from a virulent strain of the virus and cloned into prokaryotic (Escherichia coli) and eukaryotic (baculovirus) expression systems. The protein expressed by both systems was of the expected size (32 kD) and was detected by anti-IBDV antibodies. Following partial purification, the polypeptides were injected into intact birds and induced the production of high levels of anti-IBDV antibodies, as detected by immunoblot and enzyme-linked immunosorbent assay tests. These antibodies did not prevent changes in the bursa and mortality when birds were challenged with a virulent IBDV strain after vaccination with the recombinant VP3. The results show that VP3 polypeptide cannot be used as a subunit vaccine against IBDV and raise questions concerning the nature of the neutralizing epitope on this structural protein.     

The effects of bovine respiratory syncytial on normal ovine lymphocyte responses to mitogens or antigens in vitro

In the present study peripheral blod mononuclear cells (MNC) obtained from normal uninfected lambs were used to study the possible effects of bovine respiratory syncytial virus (BRSV) on lymphocyte responses to the mitogens, phytohaemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) in vitro. Live BRSV had a depressive effect on the proliferative responses of normal MNC to PHA, Con A and PWM. Inactivated BRSV and a commercial preparation of prostaglandin E2 were also found to depress the proliferative responses of normal ovine MNC to PHA but recombinant tumour necrosis factor-alpha (TNF-alpha) had no such effect. Serum samples obtained from BRSV-infected lambs contained substances inhibitory to PHA-driven lymphocyte blastogenesis. Memory blastogenic responses to border disease virus (BDV) of lymyphocytes obtained from lambs previously primed with BDV were significantly reduced when lymphocytes were exposed to infectious BRSV.     

A randomised, blinded, placebo-controlled clinical trial with allopurinol in canine leishmaniosis.

A total of 45 non-uremic dogs, with clinical signs indicating leishmaniosis, entered the study. Diagnosis was confirmed by indirect immunofluorescence assay (IFA) on serum and polymerase chain reaction (PCR) on bone marrow samples. The dogs were randomly allocated into Group A (n=37) that received allopurinol (10mg/kg B.W., per os, twice daily) for 4 consecutive months, and Group B (n=8) that were placebo-treated. Clinical signs were scored just before and at monthly intervals throughout the study period, in a blinded and independent fashion. Complete blood count, serum biochemistry profile, urinalysis, lymph node and bone marrow parasitology, IFA and enzyme-linked immunosorbent assay (ELISA) serology and bone marrow PCR were carried out at the beginning and at the end of the trial. A total of three Group A and one Group B dogs died of end stage kidney disease that developed during the trial. In Group A animals that endured the trial there was a significant improvement in the general body condition, conjunctivitis, peripheral lymphadenopathy, splenomegaly, masticatory muscle atrophy, ulcerative stomatitis, epistaxis, exfoliative dermatitis, cutaneous ulcerations, blepharitis and nasodigital hyperkeratosis. The same observation was made for anemia, lymphopenia, hyperproteinemia, hyperglobulinemia, hyperphosphatemia, increased alkaline phosphatase activity and the low albumin/globulin ratio. By contrast, no improvement of any kind was seen in Group B dogs. Lymph node and bone marrow parasite numbers were significantly decreased in Group A animals. In Group B, that occurred only in the lymph nodes. Apart from remission of clinical signs and restoration to normal of clinicopathological abnormalities, allopurinol did not eliminate Leishmania organisms, as the PCR result on bone marrow was still positive in all the dogs that finished the trial.