水产品在我国膳食中的地位和作用

本文从我国水产品生产地区分布上不平衡的特点出发,结合畜禽产品和国外情况,重点分析考察了沿海渔业区、淡水渔业区和山地高原非渔业区水产品在膳食中可能提供的动物蛋白质数量水平及其地位作用。着重指出了人口为全国30%的沿海渔业区占有全国73%的水产品,而人口为70%的淡水渔业区和非渔业区只占有全国水产品的27%。因而尽管1989年全国水产品蛋白质人均占有量仅为3.1克/人日,但沿海渔区却达到相当于世界多数渔业国的7.4克/人日的平均数量水平,并在动物蛋白质中占有平均40%的高比例水平,对保证膳食营养具有重要作用。在人口为40%的淡水渔业区蛋白质的平均占有量为2.0克/人日,在动物蛋白质中只占16.6%,但在淡水生产较快发展的前景下,90年代末仍有可能提高到现有全国平均水平3.1克/人日,部分省区有接近现有沿海渔业区水平的可能。但占有30%人口的非渔业区水产品蛋白质平均占有量仅为0.3克/人日,在提高膳食中动物蛋白质的作用上,不具有任何实质意义。     

水稻生理抗病的研究:稻株淀粉与稻瘟病发生的关系

稻株淀粉含量与稻瘟病的发生规律是明显的,有密切相关的。水稻一生,有二个时期稻株淀粉含量较少,一个是分蘖期,一个是抽穗期,而这二个时期又是最易感染稻瘟病的时期。因此,稻瘟病的发生与水稻生理有着内在的特殊关系,总的规律是稻株淀粉(在这二个时期)含量高,稻瘟病轻,反之则重。稻株淀粉含量与水稻品种的抗性有关,而且,对于气候、栽培等因素也有相互关系,而这些因素与稻瘟病的发生又有密切的关系,在几个因素中,品种的抗性是内因,而气候、栽培对于水稻属外因。然而,外因可以促使品种的抗性产生变化。因此,品种的抗性应该有两个含义,一是品种本身的(基因)抗病,另一种是外界因素给予的抗病能力,而了解稻株淀粉,掌握水稻的生理规律,对于预测预报和加强综合防治都是有实践意义的。     

Antifungal properties of pristimerin and celastrol isolated from Celastrus hypoleucus

Pristimerin and celastrol isolated from the roots of Celastrus hypoleucus (Oliv) Warb f argutior Loes exhibited inhibitory effects against diverse phytopathogenic fungi. Pristimerin and celastrol were found to inhibit the mycelial growth of Rhizoctonia solani Kuhn and Glomerella cingulata (Stonem) Spauld & Schrenk in vitro by 83.6 and 62.6%, respectively, at 10 microg ml(-1). Pristimerin showed good preventive effect (96.7% at 100 microg ml(-1)) and curative effect (66.5% at 100 microg ml(-1)) against wheat powdery mildew in vivo. For celastrol, the preventive and curative effects against wheat powdery mildew were 80.5 and 45.4%, respectively, at 100 microg ml(-1).     

Development of quantitative real-time polymerase chain reaction for duck enteritis virus DNA

Duck enteritis virus (DEV) is a herpesvirus that causes an acute, contagious, and fatal disease. In the present article, we introduce a quantitative real-time polymerase chain reaction (PCR) assay for DEV DNA using TaqMan technology and a two-step protocol. It was confirmed to be rapid, sensitive, and specific for DEV detection. The primers and probe were designed and directed to the DNA polymerase gene of DEV. The method will provide a valuable tool for rapid laboratory diagnosis of DEV infection. By virtue of its high-throughput format and its ability to accurately quantify the viral DNA, the method may be useful for large epidemiological surveys and clarification of pathogenesis, such as latency and reactivation of the virus.     

Protective immunity induced by a recombinant pseudorabies virus expressing the GP5 of porcine reproductive and respiratory syndrome virus in piglets

Pseudorabies virus (PRV) has been developed as a vaccine vector for expressing foreign immunogens. Porcine reproductive and respiratory syndrome (PRRS), caused by porcine reproductive and respiratory syndrome virus (PRRSV), continues to be a major problem to the pork industry worldwide. Many vaccine strategies have been developed to control the disease but most of them turn out to be unsuccessful. The objective of this research was to explore the feasibility of PRV-based vector vaccine in protection against PRRSV. A live attenuated vaccine-based PRV recombinant expressing the envelope protein GP5 of PRRSV was generated using recombinant DNA techniques. The Bartha-K61-derived recombinant virus, named rPRV-GP5, was shown to express PRRSV GP5 efficiently. Sixteen healthy piglets were assigned to one of four groups (one to four, four pigs per group). Animals in Groups 1 and 2 were each inoculated intramuscularly and intranasally with 10(7.0) PFU of rPRV-GP5 and its parent Bartha-K61, respectively; Group 3 were vaccinated intramuscularly with one-dose of PRRS inactivated vaccine; Group 4 was served as non-vaccinated control. One month later, all animals were all challenged with 10(6.5) TCID(50) of virulent PRRSV CH-1a. All animals in Groups 1 and 3 remained clinically healthy before and after challenge, with only a short period of fever (no more than 41 degrees C and 3 days), mild and gradually improving lung and kidney lesions, and short-term viremia (2 and 3 week, respectively) in spite of no detectable anti-PRRSV antibody before challenge. On the other hand, all animals in the other two groups showed evident clinical signs with higher temperatures (more than 41 degrees C) after challenge, and severe lung, kidney and spleen lesions and extended viremia (4 weeks). The results indicate that the rPRV-GP5 is safe for vaccinates and able to confer significant protection against clinical disease and reduce pathogenic lesions induced by PRRSV challenge in vaccinated pigs.     

Identification, Chromosome Location, and Diagnostic Markers for a New Gene (YrCN19) for Resistance to Wheat Stripe Rust

ABSTRACT Several wheat lines and cultivars of wheat (Triticum aestivum) originating from the southwestern region of China were found to be highly resistant to stripe rust by inoculation with the prevalent races (CYR30, CYR31, and CYR32) and newly emerged races (H46-4, SY11-4 and SY11-14) of the pathogen. An inheritance study of the resistance to stripe rust was carried out by crossing resistant AIM6 with susceptible BeiZ76. Results indicated that the resistance to stripe rust was controlled by a single dominant gene. The 112 F(2) plants chosen from the cross BeiZ76/ AIM6 were analyzed with 218 pairs of microsatellite primers to determine the map location of the resistance gene. A simple sequence repeat marker on chromosome arm 2BS, Xgwm410, showed polymorphism and co-segregation between stripe rust resistant and susceptible plants. From the pedigree, inheritance, molecular marker, and resistance response, it is concluded that the stripe rust resistance gene in wheat cv. Chuan-nong19 (CN19) and wheat lines AIM5 and AIM6 is a novel gene, designated YrCN19. The microsatellite primer Xgwm410 is a diagnostic marker of the resistance gene YrCN19, which has potential for application in the marker-assisted breeding of wheat.     

先兆子痫及子痫并发HELLP综合征的诊断与治疗（附4例报告）

先兆子痫及子痫并发ＨＥＬＬＰ综合征的典型症状为上腹部疼痛、恶心、呕吐及出血倾向等，以溶血性贫血、红细胞压积降低、外周血涂片见到异形红细胞、肝酶及胆红素升高，血小板减少等为主要诊断依据。小剂量阿斯匹林和潘生丁联合应用以抗血小板凝聚和及时终止妊娠是最为有效的治疗手段。     

研究花芽体外分化的一种简易体系(简报)

体外开花的研究已取得一些重大进展,这些研究所采用的外植体不同,体外诱导花芽分化的难易、分化速度及分化细胞的起源都不同,其中细胞薄层培养以其外植体体积小,内源营养物质和生长物质含量少,对外界刺激反应敏感,易于分化成为研究花芽分化的理想体系。但此法的外植体是花梗上离体的表皮和表皮下的几层薄壁细胞,其与内部组织的联系隔     

贝斯莉斯克旗草引种栽培试验初报

斯莉斯克旗草引种栽培试验结果表明，该草适应性强、耐瘠、耐酸、耐旱、抗病虫害，终年保持青绿，生长速度快，产草量高，质量好。是一种优良牧草，具有推广利用前景。     

Effects of mushroom and herb polysaccharides, as alternatives for an antibiotic, on growth performance of broilers

(1) This in vivo trial was conducted to study the effects of polysaccharide extracts of two mushrooms, Lentinus edodes (LenE) and Tremella fuciformis (TreE), and a herb, Astragalus membranaceus (AstE) on growth performance, and the weights of organs and the gastrointestinal tract (GIT) of broiler chickens. (2) Three extracts (LenE, TreE and AstE) were supplemented at inclusion rates of 0.5, 1, 2, 3 and 4 g/kg from 7 to 14 d of age and compared with an antibiotic treatment group (20 mg/kg, virginiamycin (VRG) as well as a group of non-supplemented birds. (3) Body weight (BW) gain, feed intake and feed conversion ratio (FCR) of the extract-supplemented groups were not significantly different from those of the antibiotic group. Significant effects of type of extract and concentration on growth performance were found from 7 to 28 d of age. Generally, birds fed with LenE showed higher BW gain and lower FCR from 7 to 28 d of age than those fed with TreE and AstE and 2 g/kg LenE was considered the optimal inclusion rate for enhanced broiler growth. However, the extracts had no significant effect on the relative weights of organs and GIT compared with the antibiotic group. (4) The birds fed the extracts showed better growth performance than the non-supplemented birds, but were not significantly different from those fed VRG. Of the three extracts, LenE appeared to be a potential growth promoter. Future studies are needed to investigate whether the extracts can be used as alternatives for antibiotic growth promoters in challenged birds, and to elucidate the mechanisms for potentially enhanced growth performance in poultry.