Induced transplacental transmission of Neospora caninum in cattle.

Three Jersey cows were inoculated SC and IM with 26 million Neospora caninum tachyzoites at 129 (cow 1), 126 (cow 2), and 81 (cow 3) days after mating. Cows remained clinically normal for at least 1 month after inoculation of N caninum. Cow 1 was euthanatized 32 days after inoculation because of gangrenous mastitis. Cow 1 had a live fetus with no gross lesions; however, microscopic lesions were seen in the fetus and consisted of severe nonsuppurative necrotizing encephalitis of the cerebral white matter. Neospora caninum was identified in lesions by staining with anti-N caninum serum in an immunohistochemical test, by bioassays in mice, and by inoculation of bovine monocyte cultures with fetal tissue homogenate. Neither N caninum nor lesions were associated with infection with the protozoon identified in tissues of cow 1. Cows 2 and 3 aborted small autolysed fetuses 101 and 74 days, respectively, after inoculation with N caninum; the fetuses and attached placenta were unsuitable for laboratory investigations. Cows 2 and 3 remained clinically normal 4 months after abortion. Results of this study indicated that N caninum can be transmitted transplacentally in cattle.     

大白菜和紫菜薹自交系染色体组DNA的RAPD分析

用８个随机引物（１０ｂｐ）对２个紫菜薹自交系的３个单株和４个大白菜自交系的４个单株的染色体组ＤＮＡ进行ＰＣＲ扩增，共有４０条带分离清晰、明亮，其中引条带在７个单株中表现出差异，可作为遗传标记（ＲＡＰＤ标记）。４个大白菜自交系之间的平均差异条带数为１２．３，２个紫菜薹自交系之间为９．５，大白菜与紫菜薹之间平均有１５．５条带的差异。用７个引物在９３Ｗ０５－７（紫菜薹）和９３Ｗ５８－５（大白菜）之间检测出对个ＲＡＰＤ标记。从同一自交系的不同单株抽提的染色体组ＤＮＡ扩增出较一致的ＤＮＡ谱带，而不同自交系间扩增出的ＤＮＡ谱带差异很大，这表明此方法也可以象ＲＦＬＰ一样，用于大白菜和紫菜薹的分子标记。     

甘蔗异背长蝽田间发生规律及药剂防治的研究

对甘蔗异背长蝽(次年的主要虫源)越冬卵的分布场所、不同越冬场所的孵化进度及若虫在蔗株上的分布规律,作了调查分析。对药剂防治策略和技术进行了全面的研究,提出了“主攻甘蔗异背长蝽,兼治甘蔗二点螟,狠抓一代低龄若虫防治”的策略,并采用敌敌畏加杀虫双混合液,集中喷施蔗苗心叶及基部叶鞘间隙的防治技术。经1991年在100 ha蔗田防治示范和1992年在1044.7ha大面积推广应用,收到了“一次施药,控制全年危害”的明显效果。每年每公顷可节省农药和用工费194元,每公顷增鲜蔗7980～10620kg,含糖量绝对值提高0.81％～0.85％,经济效益显著。     

辣椒黄绿苗突变体的选育及遗传分析

磁带 椒黄绿苗突变体是辣椒叶色隐性突变体。该突变体黄绿色遗传性状稳定，苗期遗传标记性状明显，抗苗期疫病等，在杂交育种及品种纯度鉴定上有极大的利用价值。     

Enzyme-linked immunosorbent assay for detection of equine infectious anemia antibody to purified P26 viral protein

An indirect enzyme-linked immunosorbent assay (ELISA) was developed for the detection of equine infectious anemia (EIA) antibody in horse sera. Purified P26 viral protein was the antigen; alkaline phosphatase linked to rabbit anti-horse immunoglobulin G was the conjugate. The ELISA detected EIA antibodies in horse sera as early as 11 to 14 days after experimental inoculations. There was full agreement between the results of ELISA and the agar-gel immunodiffusion tests on EIA proficiency test sera. The ELISA readily detected EIA antibody in horse sera that had weak positive reactions on agar-gel immunodiffusion.     

月季试管苗快速繁殖和移栽

本试验对月季实生苗进行了试管快速繁殖和移栽研究。初代培养各种激素试验中，ＭＳ＋ＢＡ２＋ＧＡ１０的培养基较好，本培养基外植体萌发快，增殖高达８～１０倍。４７代培养中产生的细弱苗，转移到壮苗培养基ＭＳ＋ＢＡ０．５＋ＮＡＡ０．５中培养２周，壮苗移植在诱导根原基的ＭＳ＋ＮＡＡ０．５的培养基中培养，经约两周左右培养产生根原基。然后，将它移植于生根培养基上，生根培养基本为１／２ＭＳ＋ＮＡＡ０．５＋３００ｍｇ／ｌ活性碳，强光条件下，温度白大控制在２８℃，夜间控制在２１℃左右。生根后移栽盆土为腐殖士：河砂：锯沫＝１：１：１。盖上烧杯封闭一周后，开始每天提烧杯０．５ｃｍ，３天后，方可移我在花盆中的腐殖土上培养。     

石灰岩区宜林荒山春季土壤含水率预测

该文利用４年的实地观测资料，进行了石灰岩区宜林荒山春季土壤含水率预测研究。采用逐步回归方法，按隔候、隔旬两个预期间隔期，建立了阳坡、半阳坡、阴坡３个坡向，５、２０ｃｍ两个土层的预测模型，平均精度９４．８％。为了解决预测间隔期内产生降水对预测结果的影响，提出了用更正系数和降水量计算更正值的方法，对预测值进行更正．     

家蚕、野蚕与桑蟥卵壳表面构造的观察比较

用扫描电镜观察了家蚕、野蚕、桑蟥卵壳的表面构造,并比较了三者间的差异。精孔区:家蚕、野蚕均有两层菊花瓣状卵纹,第三层花瓣状纹模糊不清,而桑蟥则有三层明显的菊花瓣状卵纹。卵壳中央部表面:家蚕由埂状突起交错构成小室,内含粒状突起,野蚕则小室状结构不太明显,气孔数著少,突起间交界处多生裂纹;桑蟥由许多脊状突起纵横相连,构成粗的不规则网纹,与前两者迥异。桑蟥卵壳断面构造与家蚕相似。从卵纹结构看,野蚕较桑蟥更近于家蚕。因此认为:卵纹在一定程度上反映了三者间的类缘关系。     

猕猴桃种间杂交的新种质

美味猕猴桃２６号（ＡｃｔｉｎｉｄｉａｄｅｌｉｃｉｏｓａＮｏ．２６）与软枣猕猴桃（Ａｃｔｉｎｉｄｉａａｒｇｕｔａ）种间杂交，多数杂种Ｆ１表现为中间类型偏父本，少数偏母本，由中间类型杂种雌株中选出果大、绿皮、无毛的株系。经染色体鉴定、过氧化物酶同功酶分析和杂种实生苗及其形态特征的观察，确认此种间杂种为猕猴桃属的新种质。