Sources of resistance to downy mildew in narbon (Vicia narbonensis) and common (Vicia sativa) vetches

Downy mildew (Peronospora viciae (Berk) de Bary) is an important disease of vetches (Vicia spp.) in the Mediterranean Region. Narbon and common vetch germplasm accessions originating from different countries, and advanced breeding narbon vetch genotypes, were evaluated for reaction to downy mildew for two seasons under field conditions. In narbon vetch, there were resistant sources from both germplasm accessions and advanced genotypes. From the germplasm accessions, 25 accessions were resistant while from the advanced breeding genotypes, 10 had resistance, with 2–3 ratings. In common vetch, many accessions were highly resistant to downy mildew. These were widely distributed in different countries, mainly Turkey, Italy, Syria and Iran. In general, common vetch had higher sources of resistance than the narbon vetch accessions. These new sources of resistance to downy mildew will be incorporated into the forage legume improvement project in a continuous effort to identify cultivars suitable for replacing fallow in the cereal-based cropping systems.     

钙调素与核酸在梨花芽分化中的动态研究

以梨为试格,对成花过程中ＣａＭ和核酸的含量进行了分析测定,结果表明;短枝芽的ＣａＭ含量在成花的发端期成倍增加形成高峰,而新梢芽却一直保持较低的水平;短果枝叶的ＣａＭ与新梢叶有着相近的变化趋势。但在成花前后,短果枝叶的ＣａＭ含量要明显高于新梢叶的,短枝芽所含核酸,尤其是ＲＮＡ开始回升时与ＣａＭ的峰值相吻合,并且在整个成花期间都呈上升的趋势。     

Experimental contact transmission of contagious pleuropneumonia of goats (Abu Nini) in the Sudan

Pleuropneumonia was induced in goats by inoculation of mycoplasma strain ... SGP1 (F38 type) and spread readily from them to in-contact goats which in turn passed it to other in-contact goats. This emphasises the similarity between the experimentally produced disease and classical contagious caprine pleuropneumonia (CCPP) thus supporting the view that SGP1 has an aetiological role in CCPP in the field.     

HAEMATOLOGY OF THE RACEHORSE: A Recent Study of Thoroughbreds in Victoria

ab>The study was based on 216 blood samples collected from 136 Thoroughbred racehorses in 17 stables. Lower variability in the population studied and lower means than in previous studies were attributed in part to measures taken to reduce excitement of the horses during blood collection. The demeanour of the animals during collection was assessed subjectively as placid, timid, apprehensive or excited. The five horses which became excited had significantly higher RBC, Hb, PCV, WBC, total eosinophil count, serum total protein and probably lower ESR. Timid and apprehensive horses did not show these responses. Because of the location of eight stables, samples from them were stored overnight at 4°C before analysis. These samples had higher mean MCV, PCV, MCH, and serum total protein and lower mean MCHC. The likelihood of this arising from swelling and perhaps rupture of some erythrocytes during transportation and storage was discussed. Serum total protein estimates were within the range determined from other reports from horses of various breeds. However albumin and the A/G ratio determined by electrophoresis were higher, but comparable with two other reports from Thoroughbreds. In comparative studies on the estimation of A/G ratios it appeared that equine serum albumin determination was higher using the bromcresol green reagent than by electrophoresis. After eliminating 14 cases with abnormalities of the total and/or differential leucocyte count, parameters were calculated from 202 samples for the definition of normal ranges. The absence of skewness and kurtosis indicated that the individual estimates of RBC, Hb, PCV, WBC, MCV and MCH followed the normal distribution and that the means and standard deviations were appropriate for defining normal ranges. With only ESR and TEC were the coefficients of variation, skewness and kurtosis so great as to cast doubt on the practical use of these estimates.     

Avian infectious laryngo-tracheitis in Egypt. I. Epidemiology, virus isolation and identification

Serious outbreaks of haemorrhagic tracheitis in poultry induced by infectious laryngo-tracheitis virus (ILTV) have been recorded in Egypt for the first time. The disease occurred in different localities during late 1982 and early 1983. The associated drop in egg production ranged between 5% and 35% and there was a mortality rate which ranged from 0.05% to 19.8%. The causal virus was isolated on the chorioallantoic membrane (CAM) of developing chicken embryos where it induced large yellowish-white pock lesions, 3-4 mm in diameter, by the fifth or sixth day post-inoculation. It was non-lethal to the inoculated embryos. It grew also with cytopathic effect (CPE) on the CER cell line. The CPE was characterized by syncytial formation and intranuclear inclusions. Chickens experimentally inoculated with the virus developed respiratory signs and 14 of 20 birds died with subsequent virus re-isolation. The isolated virus was unable to agglutinate chicken red cells and it was precipitated and partially neutralized by reference serum to ILTV. Viral antigen was detected by the indirect fluorescent antibody technique in tracheal smears obtained from naturally and experimentally infected birds. This is the first report of the isolation of ILTV in Egypt.