农杆菌介导抗根结线虫Bt cry6A基因转化茄子的研究

本试验以茄子下胚轴和子叶为外植体,通过对抗生素选择压筛选、不同抗生素抑菌效果比较、农杆菌侵染时间、预培养时间、共培养时间等条件优化,建立了适用于茄子的遗传转化体系,并利用农杆菌介导法将抗根结线虫Bt cry6A基因导入茄子中,以期获得抗线虫的茄子材料,探索新的抗线虫育种途径,为利用茄子转基因技术培育和改良茄子品质提供理论依据.结果表明,75mg· L-1的卡那霉素可以有效地抑制愈伤组织的产生;200mg· L-1特美汀能够完全抑制农杆菌的生长;最佳侵染外植体为子叶,在预培养4d,侵染10min,共培养1d时转化率最高;获得的56株Kan抗性植株中有15株具有GUS活性;经过PCR、RT-PCR验证,初步确认Bt cry6A基因已整合至茄子基因组中,并在转录水平上正常表达;根结线虫幼虫接种鉴定表明,转Bt cry6A基因茄子再生植株对南方根结线虫抗性明显提高.     

Sr18菌代谢产物对线虫应激能力的影响

基于Sr18菌代谢产物在24 h内具有显著的杀线虫活性,为进一步探究其杀线虫机理和作用规律,测定其在16 h内对线虫应激能力的影响。结果表明,在4 h时处理组对外界条件刺激的敏感性明显提高,运动频率均高于对照组,表明4 h为Sr18菌代谢产物对线虫产生作用的转折点;8 h后处理组活跃程度明显减弱,对刺激的反应较对照组缓慢,随着刺激时间增加,处理组的活跃性有所增加但不显著,表明Sr18菌代谢产物已产生明显的药效作用,致使线虫对刺激反应迟钝。Sr18菌代谢产物对线虫应激能力的影响呈现"平稳-上升-下降"的规律,进一步探究Sr18菌代谢产物的作用机理为实践中的合理用药提供理论依据。     

Effect of a single dry season anthelmintic treatment of N'Dama cattle on communal pastures in The Gambia

The effect of a single anthelmintic treatment of cattle during the early dry season was studied. One hundred and sixty-six N'Dama cattle, 1–3 years old, were selected from five herds. There were 65 males and 101 females divided into two groups of 83 animals each. One group was treated with fenbendazole at 7.5 mg/kg body weight by mouth in November 1992; the other group remained as the untreated control. At monthly intervals from November 1992 to April 1993, each animal was weighed and the number of eggs/g of faeces (epg) was determined. The infective larvae (L3) were examined following culture of pooled samples from each group of animals. In April 1993, 6 animals (3 treated and 3 controls) from the herds under study were necropsied. The difference in the weight gains (4.6 kg) of the two groups was highly significant (p<0.0001). The difference in the weight gains and the epg between the treated and control groups was influenced by the age of the animals. Of the treated animals, one contained no nematodes, one contained only 25Oesophagostomum radiatum, and the third contained 25Cooperia L4. The three untreated animals were all infected. It was concluded that the treatment in early dry season, with an anthelmintic effective against both adults and larvae, led to a significant reduction in egg counts, to elimination of adults and hypobiotic larvae and, consequently, to an increase in the body weight gain by the treated animals.     

用昆虫病原线虫液相培养早期发育指标预测产量的研究

对液相培养繁殖昆虫病原线虫的早期发育指标与最终产量的相关性进行研究，探讨利用早期发育指标预测最终产量的可能性。试验中采用４项早期发育指标：（１）接种代发育比（培养第４天）；（２）接种代繁殖倍数（培养第９天）；（３）子１代发育比（培养第１３天）；（４）子１代繁殖倍数（培养第１８天）。回归分析结果表明，４项发育指标与最终产量均有显著相关性，可以用作预测最终产量的指标。     

ULTRASONOGRAPHIC FEATURES OF PARAPROSTATIC CYSTS IN NINE DOGS

The ultrasonographic features of paraprostatic cysts in nine dogs are described along with historical, clinical, surgical and pathologic findings. Cysts occurred predominantly in older, large breed dogs (mean age 8 years, range 3–11 years). The most common presenting complaints were depression, inappetance, stranguria, tenesmus and bloody penile discharge. A palpable abdominal mass was the most common physical finding. Ultrasonographically, paraprostatic cysts were usually large anechoic structures; many contained internal septa. Moderately large anechoic cavities or cysts were also detected in the prostatic parenchyma of five dogs, and in two of these communication with the paraprostatic cyst was visualized. There were no clearly distinct ultrasonographic criteria to discriminate septic from nonseptic paraprostatic cysts.     

HYPOTHYROIDISM IN A DOG AFTER SURGERY AND RADIATION THERAPY FOR A FUNCTIONAL THYROID ADENOCARCINOMA

Hypothyroidism was diagnosed in a dog which had undergone unilateral thyroid lobectomy and external beam irradiation (48 Gy in 3 Gy fractions) for a functional cystic thyroid adenocarcinoma. Hypothyroidism became biochemically apparent within 4 months of completion of radiation therapy, and clinically apparent within 7 months. Clinical signs resolved after thyroid hormone supplementation. The potential for alterations in thyroid function should be considered in any animal undergoing radiation therapy in which the thyroid gland is included in the radiation field. This potential may be greater if surgery and radiation are combined.     

杨梅根结线虫病研究

杨梅根结线虫病是一种新发现的杨梅病害,病原线虫为爪哇根结线虫(Meloidogynejavanica)、南方根结线虫(M.incognita)和北方根结线虫(M.hapla).爪哇根结线虫为优势种.病害的影响因素有果树品种、种植年限、种植方式和土壤pH值.呋喃丹对病害具有防治效果.调节土壤pH值和用客土改良土壤可以减缓病害和促进果树生长.     

广州地区草坪线虫初步调查鉴定

为了解广州地区草坪线虫种类的分布情况，从广州市12个不同地点的运动型、观赏型、游憩型草坪和草圃采集草根样品，经贝曼漏斗法分离线虫，用TAF固定液杀死，依甘油慢法制作玻片，采用de Man公式测量计算，按T.Goodey和J.B.Goodey的分类系统进行鉴定，初步鉴定出线虫23种，其中6种为中国地理新记录。这些线虫种类中植物寄生线虫8种、植物病原线虫3种、食肉线虫5种、食菌线虫9种、食腐线虫6种，表明广州地区草坪线虫种类资源丰富，生物习性多样。     

松材线虫对湖南林业和生态环境影响的风险性分析

遵循国际植物保护公约（IPPC）制定的有害生物分析准则，结合森林植物检疫对象的特点，从地理和管理标准、传入、定殖、定殖后扩散的可能性、潜在的经济和环境重要性在对松材线虫传入湖南进行了风险分析。证明松材线虫完全符合检疫性有害生物地理和管理标准，随松类植物及产品的调运从国内外疫区传入的可能性极大，在湖南完全能够定殖，定殖后能迅速扩散并暴发成灾，不仅对全省林业生产影响极大，而且严重威胁世界自然遗产武陵源风景区的安全,提出了3种降低风险的管理措施。     

Development and validation of species-specific primers that provide a molecular diagnostic for virus-vector longidorid nematodes and related species in German viticulture

The nematode species Longidorus attenuatus, L. elongatus, L. macrosoma and Paralongidorus maximusare economically important pests to the viticulture industry due to their ability to vector two nepoviruses (Raspberry Ringspot Virus and Tomato Black Ring Virus) to grapevines. In Germany, these species occur in vineyard soil with other non-vector but morphologically similar longidorid species, L. helveticus, L.profundorum and L. sturhani. Species-specific primers were designed from ribosomal DNA for all seven species to facilitate taxonomic identification for non-specialists. Primers were assessed for their reliability by screening, where possible, a number of populations of each species. Furthermore, their selectivity and sensitivity were determined when challenged with closely related longidorid species and general nematode communities typical of vineyard soil. A multiplex approach using a common forward primer combined with species-specific reverse primers enabled three target nematode species to be detected in the same PCR reaction. All primers were highly specific, detecting all nematode developmental forms from disparate populations and were sufficiently sensitive to detect a single target nematode within a whole nematode community typical of a vineyard soil comprising of a range of non-target species. Given their specificity, sensitivity and reliability, these diagnostic primers should be of great benefit to both phytosanitary/quarantine services related to the viticulture industry and also as a decision management tool for growers.