柑桔黄龙病病原类细菌分离培养及其感病性研究

笔者首次成功地人工培养柑桔黄龙病病原类细菌（BLO）,以此为抗原制备免疫抗血清,对黄龙病诊断获得满意结果。BLO阴性,菌落多为圆形,无色至褚红色,大小为0.09-0.18mm,培养初期,菌体两端钝圆,大小为(200-600nm)×(670-2000nm),菌体表面呈波纹状,胞壁厚16-25nm,培养约10天左右,菌体一端沿纵轴延伸一长柄,柄长约与菌体等长或更长些,大小为(45-92nm)×3500nm。 BLO通过虫传、注射、浸根和剥皮等接种方法接种于健康的柑桔幼苗,表现出典型的黄龙病症状,接种发病的植株,再次分离到同样的BLO。在电镜观察下,证实该病原存在于筛管细胞,用不带病的柑桔木虱吸食BLO,作传病试验,获得成功。     

"双黄"在鸭胚中抗鸭瘟病毒的效力试验

用双黄杀毒退烧颗粒剂(简称“双黄”)对8组鸭胚予以不同剂量的抗鸭瘟病毒效力试验,结果表明其在鸭胚中能抑制鸭瘟病毒增殖。     

A specific and sensitive assay to quantify the herbicidal activity of chloroacetamides

Based on a recently discovered property of chloroacetamide herbicides—the inhibition of the incorporation of oleic acid into sporopollenin of Scenedesmus acutus—a rapid quantitative test was developed for chloroacetamide-type herbicidal activity. In this test, algal cells are incubated for 3 h with [¹⁴C]oleic acid, saponified and the lipids (including non-saponifiable ones) extracted and discarded. The radioactivity incorporated into the residual non-lipid fraction is determined, and inhibition of this incorporation is used as a marker of chloroacetamide-type activity. Twenty-two agrochemical compounds were screened in this assay, which was found to be very sensitive, a 50% inhibition being reached with submicromolar herbicide concentrations. It is specific to chloroacetamides and related amides, since all these herbicides tested were potent inhibitors, while other herbicides were not. Highest inhibition was shown by cafenstrole followed by butachlor, fluthiamid, metazachlor, alachlor, dimethenamid, metolachlor and mefenacet. For these herbicides (with the exception of butachlor) sensitivity in the test was positively correlated (r=0·984) with their phytotoxic effect on the alga. © 1998 SCI     

36株生防菌对辣椒疫病等4种病原真菌的拮抗作用研究

采用拮抗菌发酵液、皿内竞争及紫外线照射菌株代谢产物等方法,研究了36株生防菌对辣椒疫病、西瓜枯萎病、棉花枯萎病及黄瓜枯萎病4种病原真菌的拮抗作用。结果表明:(1)4种病原真菌在含有不同拮抗菌发酵液的平板上生长时,均受到不同程度的抑制,说明供试拮抗菌对4种病原真菌具有拮抗作用。36株供试拮抗菌对辣椒疫霉、西瓜枯萎菌、黄瓜枯萎菌和棉花枯萎菌有抑制效果的菌株数分别为30(占83.3%),27(占75%),24(占66.7%)和26(占72.2%)株。(2)36株供试拮抗菌中,与辣椒疫霉、黄瓜枯萎菌、棉花枯萎菌及西瓜枯萎菌具有竞争抑制作用的拮抗菌分别有19(52.7%),10(27.8%),6(16.8%)和11(30.6%)株。(3)菌株95W06,64G12,87W14,63G06,03GY022,31-4G02,28G14及10G27对辣椒疫霉菌具有抑制作用,其代谢产物经紫外线照射后,均失去对辣椒疫霉的抑制作用,表明此8株拮抗菌的代谢产物活性成分不稳定。(4)利用拮抗菌与病原菌的竞争抑制试验,可以从大量拮抗性菌株中快速筛选出有实际防效的生防菌。     

CEL I酶的高效检测及其在Eco—TILLING中的高效应用

CELI酶是Eco—TILLING技术的关键酶。实验采用酶切连接的方法构建了酶切位点上插入突变的质粒,应用该质粒能方便有效地检测CELI活性。进一步简化CELI酶的提取方法,并对每一步提取液样品进行活性检测。结果表明,芹菜汁也具有明显的酶切活性,进一步的提纯能提高其活性,琼脂糖凝胶电泳也能获得直观的检测结果,通过简化程序可高效应用于植物Eco-TILLING分析。该研究结果有利于Eco—TILLING技术的广泛使用,对于建立简易而又有效的点突变检测方法具有重要的意义。     

Molecular characterization of Cereal Cyst Nematode diagnostic markers Cre1 and Cre3 in some winter wheat germplasm and their potential use against Heterodera filipjevi

Two PCR based markers tightly linked to Cre1 and Cre3 resistant genes against the Cereal Cyst Nematode (CCN, causal agent Heterodera avenae) were used to characterize a number of diploid, tetraploid and hexaploid wheat germplasm consisting of obsolete, advanced lines and new cultivars from the Turkish National Breeding Program and the joint TURKEY CIMMYT ICARDA International Winter Wheat Improvement Program. In addition a number of landraces and wild relatives of wheat collected from the Turkish side of the Fertile Crescent, the centre of origin of cereals, were included. None of the genetic material tested positive for either marker except the land race Sardari which originated from neighboring Iran was found positive for Cre1 gene. Combining both of these molecular markers in one assay for fast and cost-effective screening of the germplasm was not effective, so marker genotyping with germplasm was realized using each primer alone. Most work that has been reported is on the CCN species H. avenae, however the predominant species in Turkey is the closely related H. filipjevi. In vitro resistance assaying for this species indicates that Cre1 is a moderate source of resistance against the H. filipjevi population, however Cre3 gene appears ineffective. It is suggested that a larger pool of a range of germplasm should be screened for Cre1 in Turkey. Furthermore, the landrace Sardari could be used as a parent to deploy CCN resistance in to genetic background of Turkish bread wheat cultivars with a targeted Marker Assisted Selection Backcrossing approach.     

应用生物素-链霉亲和素的酶联免疫吸附法检测谷物中的玉米赤霉烯酮

基于生物素-链霉亲和素的酶联免疫吸附法(ELISA),建立了玉米赤霉烯酮(ZEN)的ZEN-ELISA检测方法。该方法的检测灵敏度为0.8 ng/ml,批内、批间变异系数分别为5.1%和8.6%,平均加样回收率为91.2%;抗ZEN单克隆抗体与玉米赤霉醇的交叉反应度为12.3%,而其与赭曲霉素A、脱氧雪腐镰刀菌烯醇、黄曲霉素B1无交叉反应;相关试剂在4℃存180 d后各检测参数基本无变化;该方法与商品ELISA试剂盒对同一样品ZEN测定结果的相关系数为0.943 2。说明该方法的特异性和稳定性较好,测定结果准确,可用于ZEN的大量筛查。     

几种乳杆菌协同作用对产生大果沙棘籽油共轭亚油酸的影响

以乳化的沙棘(Hippophae rhamnoides L.)籽油作为底物加入到试验所制备的复合乳杆菌中,利用乳杆菌所产生的亚油酸异构酶使亚油酸(LA)转化为共轭亚油酸(CLA).通过几种轧杆菌不同配比组合的协同试验,发现不同种乳杆菌的协同转化共轭亚油酸的能力要高于单一茵种.结果表明,复合乳杆菌中植物乳杆菌:德式乳杆菌保加利亚亚种为7:3转化效果最好,其亚油酸异构酶酶活为21.36 U/mL,共轭转化率为33.38%,共轭亚油酸质量浓度为28.83g/L.     

哺乳动物精子检测技术研究进展

普通光学显微镜检测精液存在主观性、可变性、分析的精子数量少和与受精能力相关性差等缺点。近些年来,一些新的技术用于检测精子,可以更加细致地评价精子的特性。荧光染色技术可以用于评价精子的特殊性质和功能,包括质膜完整性、获能状态和顶体状态。联合使用荧光染料,可以同时检测精子几种功能特点。流式细胞仪可以在短时间内分析大量的经荧光标记的精子。计算机辅助精子分析系统可以提供精子活力和形态学上客观的和详细的信息。通过检测精子与透明带或者输卵管上皮附着、精子穿透卵母细胞,可以获得精子受精能力的信息。未来的研究方向仍是寻找有效的预测精子受精能力的参数。     

常见淡水鱼肉制品快速鉴别方法的建立

近年来,随着肉制品掺假问题日益突出,特别是鱼肉制品中掺入廉价成分,混淆鱼肉品种,以次充好的掺假造假问题引起广泛关注.为解决这一问题,有必要针对常见的青鱼(Mylopharyngodon piceus)、草鱼(Ctenopharyngodon idellus)、鲢(Hypo-phthalmichthys molitrix...