Epidemiological aspects and transmission routes of bois noir (BN), a grapevine yellows disease induced by ‘Candidatus Phytoplasma solani’, have been exhaustively studied in the affected vineyards of continental Europe but not in the Mediterranean coastal zone. Because ‘Ca. Phytoplasma solani’ and its principal vector Hyalesthes obsoletus presumably originate from the Mediterranean, gaining knowledge of the epidemiological peculiarities of the disease in this area is essential for understanding its global spread and diversification, as well as for designing local management strategies. In this study, molecular epidemiology was applied to trace transmission pathways of ‘Ca. Phytoplasma solani’ in the Mediterranean vineyards of Montenegro, using multilocus sequence typing of tuf, vmp1 and stamp genes of the isolates associated with various hosts. Thus, ‘Ca. Phytoplasma solani’ was tracked from a tentative reservoir plant (inoculum source) through an associated vector population to the infected grapevine. Three pathways of transmission were documented, originating from Urtica dioica, Convolvulus arvensis and Vitex agnus‐castus; however, only the route originating from U. dioica was direct, whereas the latter two were overlapping and could be intermixed. Vitex agnus‐castus is a natural source of ‘Ca. Phytoplasma solani’, representing an important link in disease epidemiology in the Mediterranean and a possible origin of several genotypes occurring in central Europe. Experimental confirmation of the role of Vitex‐associated H. obsoletus in BN transmission in Montenegrin vineyards indicates its tentative role as a vector in the wide area of the Mediterranean, where some of the major wine‐producing regions are located. 相似文献
This study aimed at revealing arterial vascularization of the pineal gland of the Zavot-bred foetus. Twenty foetuses, regardless of their sex, at the age of 2-7 months were used. Coloured-latex was injected by way of both the right and left common carotid arteries. Then, dissection was performed and vessels nourishing the pineal gland were documented. The pineal gland is vascularized by a number of 2-5 central rami. A small vessel arising from each of the central rami in two foetuses (10%) was shown anastomosing with a branch of the cranial cerebral artery, which advances in cranio-caudal direction in the callosal groove. Hence, anastomoses were observed between several sub-branches of each caudal cerebral and cranial cerebellar arteries. 相似文献
Blood samples were collected from 69 ‘healthy’ female alpacas aged ≥12 months from 11 properties in South Australia. The 10–90 percentile ranges of the 16/19 analytes measured in this sample population were within the published ranges of four healthy alpaca populations from other geographic locations. Marginal exceptions were glutamate dehydrogenase and bicarbonate. Potassium was notably elevated, probably because of haemolysis of some samples. The sample size was insufficient to provide the appropriate statistical power to define diagnostic references ranges according to international standards. The health status of the sample population of alpacas was presumptive based on a physical examination. 相似文献
Monoclonal antibodies directed against porcine immunoglobulin isotypes G, G1, G2, M, and A and against chicken immunoglobulin isotopes G, M, and A were tested in an antigen-specific spot-forming cell (SFC) assay based on the principle of the enzyme immunoassay. The SFC assay was used to quantitate ovalbumin (OA)-specific antibody-secreting cells (ASC) in pigs that had been primed and boosted with OA. The SFC assay was also used to quantitate trinitrophenyl (TNP)-specific ASC in chickens that had been primed with TNP-conjugated keyhole lympet haemocyanin (TNP-KLH). Although, the classical plaque-forming cell (PFC) assay cannot reliably detect isotope-specific ASC in pigs and chickens, it can detect these cells in mice. Therefore, we compared the OA- and TNP-specific SFC assays with PFC assays that were specific for these antigens in mice. The study demonstrated that the SFC assay is superior to the PFC assay in detecting both OA-specific ASC and TNP-specific ASC. The frequencies of OA-specific and TNP-specific SFC detected in mice were of the same order of magnitude as those detected in pigs and chickens. We concluded that the SFC assay is the better method for quantitating ASC in pigs, chickens, and probably all domestic animals for which isotype-specific monoclonal antibodies are available. 相似文献
1. The effect of reducing food intake to 75% of the ad libitum intake was determined from hatching to 8 weeks in young Light Sussex chickens.
2. Restricted birds were lighter throughout the experiment.
3. Relative adrenal weight tended to be greater in restricted birds but the difference decreased with time.
4. There was no depletion of adrenal cholesterol: from week 5 there was a significantly greater amount in the adrenals of restricted birds.
5. After 1 week of restriction plasma corticosterone concentration was 73% greater than in controls. It decreased progressively, falling within the normal range at 5 weeks.
6. Restricted birds were hypoglycaemic from weeks 2 to 7 and hyper‐lipacidaemic throughout. A negative correlation between plasma glucose and free fatty acids was found. 相似文献
Epizootic ulcerative syndrome was diagnosed, and the presence of Aphanomyces invadans confirmed, from an outbreak of clinical disease in wild‐caught bony bream (Nematalosa erebi) from the Darling River near Bourke, in New South Wales, Australia, during 2008. This confirms a significant extension of the agent beyond its historical range. 相似文献
Conidia ofAlternaria linicola produced on infected linseed crops were mainly dispersed by wind. The numbers of conidia in the air above linseed crops collected by a Burkard spore sampler were greatest between 1200 h and 1300 h, when the relative humidity was lowest. Although numbers of conidia collected decreased with increasing height within and above the crop canopy, air-borneA. linicola conidia were present up to 80 cm above the crop canopy. Conidia ofA. linicola were transported by wind up to at least 40 m downwind from an artificial line inoculum source, but their numbers decreased with increasing distance from the source. In 1991, 1992, and 1993, the dispersal ofA. linicola conidia above linseed crops followed a seasonal periodicity which was influenced by weather conditions and cultural practices. The greatest numbers of conidia were collected during July, August and early September and coincided with periods favourable for sporulation and with an increase in the incidence of the disease in the senescent crop. Air-borneA. linicola conidia produced on point or line inoculum sources (naturally infected linseed stem debris) were responsible for the spread of the disease in linseed crops. In 1992 and 1993, the disease was first detected downwind from the sources, but by the end of the growing seasons, it had spread in all directions and up to 20 m and 60 m from the sources, respectively. Disease gradients were initially steep near the inoculum sources but they became flatter with time due to the secondary spread of the disease. 相似文献
Bull’s eye rot is a typical quiescent postharvest apple disease in major fruit-growing areas. The susceptibility of different apple cultivars to Neofabraea spp. (N. vagabunda and N. malicorticis) was assessed, with Granny Smith showing the most resistance and Cripps Pink the most susceptibility. To assess the factors involved in conidial germination, Neofabraea spp. were grown on crude protein extracts (CPEs) collected from apple fruits at different storage periods. Fungal germ tube growth rate and pathogenic enzyme (cellulase and xylanase) activity were assessed. Results showed that CPEs collected after 2 and 4 months of storage progressively stimulated conidial germination and germ tube elongation, while a lesser effect was observed from CPEs after 1 month of storage. Xylanase proved to be the main degrading enzyme secreted by all the isolates, while cellulase was produced only by N. vagabunda isolates. Overall, the isolate ID02 was the most virulent, based on more rapid germ tube elongation and greater activity of the lytic enzymes. 相似文献