草地早熟禾新品种特异性、一致性和稳定性测试指南初报

在系统调研国内外文献,广泛收集草地早熟禾种质,连续2年温室幼苗性状评估,连续3年田间性状评价和广泛征求专家意见的基础上,首次编制了我国草地早熟禾特异性、一致性和稳定性(DUS)测试指南。指南在形式与主要内容上,与国际植物新品种保护联盟(UPOV)的草地早熟禾测试指南相协调,包括测试的总体技术要求、性状表、性状解释和技术问卷4部分;在性状与标样品种确定上主要参照了UPOV和日本的测试指南。     

Resistance to early blight of tomato with respect to various parameters of disease epidemics

Resistance to early blight in the tomato was assessed by examining various parameters of the progress of the disease. Artificial inoculation and the scoring technique were standardized. Test plants were inoculated with 125cfu/ml of a 12-day-old culture of a pathogenic isolate of Alternaria solani. Screening under artificial conditions was more informative than that under natural epidemic conditions. Tomato cultivars CLN-2071-C, CLN-2070-A, BSS-174, and DTH-7 with resistance expressed as slow blighting against four pathogenic isolates of A. solani, were selected for cultivation in disease-prone areas. Disease intensity increased with the age of plants under the same inoculum load. The area under the disease progress curve (AUDPC) was positively correlated with the percentage disease index and negatively with resistance. Calculation of the apparent infection rate (r) was more informative for natural epidemics than for artificial conditions. The sequential apparent infection rate between observation periods was better correlated with disease progress than was the total apparent infection rate between the first and last observations. A double sigmoidal disease progress curve during the same cropping season was characteristic of some varieties when fungal infection took place during the vegetative phase of crop growth.     

Immunological responses of the lactating ovine udder following experimental challenge with Staphylococcus epidermidis

The responses of five lactating ewes to experimental mammary infection with Staphylococcus epidermidis were examined. Infection caused an intense but transient influx of neutrophils into milk, which peaked at 8 h and was accompanied by mild fever and mild leukopaenia in blood. No other signs of systemic infection were observed. Number of staphylococci in milk decreased logarithmically until 24 h, were absent from three ewes at 48 h and then increased in number or re-emerged in four of the five ewes at 72 or 144 h. At all times milk appeared grossly normal. Expression of the adhesion molecules CD11b and CD18 increased on neutrophils in milk at 24 h then tended to decline over subsequent days. The proportion of lymphocytes positive for CD4, CD8, WC1 and MHCII tended to decrease from 24 to 72 h then increased at 144 h. Cytokines in milk were measured by ELISA. IL-8 was elevated in infected glands at 2 h, peaked at 24 h and remained elevated until the final sampling at 144 h. IL-6 was transiently elevated at 4 and 8 h while IL-1beta remained elevated from 8 until 144 h. The results suggest that the intense early neutrophil infiltrate eliminated most but not all bacteria and a state of subclinical infection ensued. After 24 h , leukocyte numbers in milk declined while cytokines, especially IL-8 remained elevated, suggesting that sensitivity or responsiveness of gland to inflammatory signals decreased as infection progressed. This attenuation of the host defence response may have contributed to the failure of the gland to eliminate bacteria and may be an important feature of the development of chronic and subclinical mastitis.     

Towards the first linkage map of the<Emphasis Type="Italic">Didymella rabiei</Emphasis> genome

A genetic map was developed for the ascomyceteDidymella rabiei (Kovachevski) v. Arx (anamorph:Ascochyta rabiei Pass. Labr.), the causal agent of Ascochyta blight in chickpea (Cicer arietinum L.). The map was generated with 77 F₁ progeny derived from crossing an isolate from the U.S.A. and an isolate from Syria. A total of 232 DAF (DNA Amplification Fingerprinting) primers and 37 STMS (Sequence-Tagged Microsatellite Site) primer pairs were tested for polymorphism between the parental isolates; 50 markers were mapped, 36 DAFs and 14 STMSs. These markers cover 261.4cM in ten linkage groups. Nineteen markers remained unlinked. Significant deviation from the expected 1:1 segregation ratios was observed for only two markers (Prob. of χ²<0.05). The implications of our results on ploidy level of the asexual spores are discussed. http://www.phytoparasitica.org posting Sept. 5, 2002.     

Splenectomy enhances sensitivity of islets to STZ in mice

AIM: To explore the protective role of spleen in damage of islet beta cells induced by streptozotocin (STZ).METHODS: Splenectomy in mice was performed by surgery. Sixty splenectomy mice were divided into 3 groups as the mice were intraperitoneally injected with STZ at doses of 80 mg/kg or 160 mg/kg, and saline, respectively. Sixty normal mice (without splenectomy) were also grouped and treated as above for controls. One week later, fasting blood glucose and serum insulin were monitored,and beta cell mass and the apoptosis of islet cells were analyzed by the methods of immunohistochemistry and ELISA, respectively. The content of reactive oxygen species was determined by the method of luminol-enhanced chemiluminescence.RESULTS: Compared to the normal control mice, the concentrations of fasting blood glucose significantly increased, and serum insulin reduced in splenectomy mice treated with STZ at the dose of 80 mg/kg. Moreover, beta cell mass decreased, enrichment factor of nucleosomes of islet apoptotic cells and reactive oxygen species produced in pancreas tissues significantly increased in splenectomy mice treated with STZ at the dose of 80 mg/kg.CONCLUSION: Splenectomy increases the sensitivity of islets to STZ in mice by increasing the production of reactive oxygen species in pancreas.     

Effects of varying nitrogen doses on yield,yield components and artemisinin content of Artemisia annua L.

Artemisia annua L. is an aromatic-antibacterial herb that destroys malarial parasites, lowers fevers and checks bleeding, and of which the secondary compound of interest is artemisinin. The objective of the present study was to determine yield, yield components and artemisinin content of A. annua L. grown under four nitrogen applications (0, 40, 80 and 120 kg ha⁻¹) in the Çukurova region of Turkey in 2004 and 2005. Field trials were conducted at Çukurova University, Agricultural Faculty Field Crops Department. In the study, plant height, number of branches, fresh herbage yield, dry herbage yield, fresh leaf yield, dry leaf yield, essential oil content and artemisinin content (by high performance liquid chromatography, HPLC) were examined. By analysis of variance, nitrogen doses had no any statistical effect on the traits investigated except for artemisinin content. Artemisinin content of the dried leaves were significantly affected by nitrogen applications, which varied from 6.32 to 27.50 mg 100 g⁻¹. Contents were from 120 and 80 kg ha⁻¹ nitrogen for the years of 2004 and 2005, respectively.     

不同处理玉米的有机物质瘤胃降解率及小肠消化率的研究

用３头带瘤胃瘘管的杂种肉牛测定玉米、无机保护剂处理玉米、有机保护剂处理玉米、１０％和３０％鲜血处理玉米有机物质（ＯＭ）和非蛋白质有机物质（ＮＰＯＭ）的瘤胃动态降解率，ＯＭ分别为５３．０３％，４３．９１％，５３．５７％，３５．７３％和３８．８５％，ＮＰＯＭ分别为５３．６７％，４８．０６％，５５．７２％，３９．２４％和４４．４８％。用酶解法（牛小肠液冻干粉（ＢＩＦ））测得玉米、无机保护剂处理玉米、有机保护剂处理玉米、１０％和３０％鲜血处理玉米１２小时瘤胃非降解ＯＭ的消化率分别为７４．３９％，７６．２６％，７５．５４％，７７．８８％和７７．４３％，ＮＰＯＭ分别为６３．９２％，６４．７８％，６４．４３％，６７．７８％和６５．００％。     

Immune response of cattle to Brucella abortus outer membrane proteins measured by lymphocyte blastogenesis

Lymphocytes from cattle were tested in a blastogenesis test with outer membrane proteins isolated from smooth strain 2308 and rough strain 45/20 of Brucella abortus. The titration assay developed for measuring blastogenesis to microbial antigens (Baldwin, Antczak and Winter, this issue, pp. 319-333) was used to assess the response to both group 2 (porins) (Douglas et al., 1984) and group 3 proteins (Verstreate et al., 1982). Blastogenesis was evaluated for distinguishing cattle infected with virulent B. abortus strain 2308 from unimmunized cattle, cattle vaccinated with attenuated strain 19, or inoculated with Escherichia coli 0116:H31, known to cause serological cross-reactions with B. abortus (Nielsen et al., 1980). Strain 45/20 porin was the most effective for this purpose and data analyses utilizing the titration assay were better than those relying on a single point assay. When compared with BASA, an antigen preparation used in other studies (Kaneene et al., 1978a), responses to porin provided a more specific index of infection with B. abortus. Reactions to 45/20 porin occurred, however, in some heifers vaccinated as adults with strain 19 or inoculated with E. coli 0116:H31. Furthermore, nonpregnant heifers had negligible or only transient blastogenesis responses to the porin during the first 14 weeks after infection even though they developed strong 0 antibody responses. We do not recommend the blastogenesis test in its present form as a useful adjunct to serological tests, and could allow measurement of cell mediated immune responses relevant to protective immunity.