袖珍椰子水培试验研究

本试验以盆栽健壮的袖珍椰子为试材,采用水培法经不同浓度的ATP生根粉处理,进行诱导水生根系试验,然后用诱导的水生根系材料进行营养液培养。结果表明:当ATP生根粉浓度为100 mg/kg时,对袖珍椰子生根系的诱导效果最好,驯化的水生根系数量多、粗壮,且生根时间最早;1/4 MS营养液最适合袖珍椰子的生长,各项生长指标最好。     

Amphidial structure of ivermectin-resistant and susceptible laboratory and field strains of Haemonchus contortus

The development of anthelmintic resistance by nematode parasites is a growing problem for veterinarians, pet owners, and producers. The intensive use of the macrocyclic lactones for the treatment of a variety of parasitic diseases has hastened the development of resistance to this family of parasiticides. As a result, resistance to ivermectin, moxidectin, nemadectin, and doramectin by Haemonchus contortus has been documented throughout the world.

Sensory neurons located in the cephalic end of nematodes are in close contact with the external environment. Through these neurons, important chemical and thermal cues are gathered by the parasite. Examination of serial electron micrographs of ivermectin-susceptible and ivermectin-resistant H. contortus allows for comparison of neuronal structure, arrangement of neurons within the amphidial channel, and distance of the tip of the dendritic processes to the amphidial pore. The latter of these characteristics provides a useful means by which to compare the association between the neurons and the external environment of the worm.

Comparison of parental laboratory strains of ivermectin-susceptible strains of H. contortus with related selected, ivermectin-resistant strains and with a wild-type ivermectin-susceptible field strain of H. contortus from Louisiana reveal that the ivermectin-resistant worms examined have markedly shorter sensory cilia than their ivermectin-susceptible parental counterparts. Additionally, the amphidial neurons of ivermectin-resistant worms are characterized by generalized degeneration and loss of detail, whereas other neurons outside of the channels, such as the labial and cephalic neurons, are normal in structure. These findings raise a number of questions regarding the relationship between amphidial structure and ivermectin resistance as well as the role of amphids as a means of entry for ivermectin. While shortened amphidial sensilla are associated with ivermectin resistance, it remains unclear if such a structural modification facilitates survival of nematodes exposed to macrocyclic lactones.     

牛源大肠杆菌对秀丽隐杆线虫的致病性研究

为建立牛源大肠杆菌-秀丽隐杆线虫致病模型,本研究从广西南宁、桂林、柳州等地区收集的牛病料中分离出13株大肠杆菌,继而对这些大肠杆菌进行血清学鉴定及小鼠、秀丽隐杆线虫的致病性试验。采用玻片凝集法鉴定大肠杆菌的O血清型,并将13株大肠杆菌培养液以3.0×10⁹ CFU/mL、0.2 mL/10 g体重给小鼠腹腔注射,同时分别喂食N2野生型秀丽隐杆线虫。结果显示,大肠杆菌的O血清型为O127、O126和O44,其中O126为优势血清型（4/13）。致病性结果显示,有11株大肠杆菌能使小鼠致死（致死率为40%~100%）,2株大肠杆菌对小鼠没有致死性（致死率为0）。对小鼠有强致病性的大肠杆菌,对线虫的致死率也较高,死亡率在第3~6天最为显著,半数致死时间为3~4.5 d,最长存活时间为9 d;对小鼠不致死的两株大肠杆菌对线虫的致死率也较低,线虫死亡率下降趋势缓慢,半数致死时间为5~6 d,最长存活时间为10~11 d。肠道细菌计数结果显示,大肠杆菌在线虫体内的数量与时间呈线性关系,大肠杆菌不断破坏线虫的免疫系统,从而导致了线虫的死亡。本研究结果表明,大肠杆菌对线虫和小鼠的致病力试验结果一致,说明成功建立了牛源大肠杆菌-秀丽隐杆线虫致病模型,为牛病防治与临床用药提供了依据。     

牛耳皮肤成纤维细胞的分离培养及转染线虫ω-3脂肪酸去饱和酶基因研究

为了核移植法制作转线虫ω-3脂肪酸去饱和酶基因克隆牛提供供体细胞,体外分离培养牛耳成纤维细胞并进行了线虫ω-3脂肪酸去饱和酶基因.采用胰蛋白酶消化法分离培养牛耳皮肤成纤维细胞,线虫ω-3脂肪酸去饱和酶基因表达载体以脂质法介导转染细胞,通过G418筛选9d获得稳定转染的细胞克隆.PCR鉴定外源基因在细胞基因组中的整合,对...     

秀丽隐杆线虫研究综述

国内外对秀丽隐杆线虫的研究日益增多,秀丽隐杆线虫作为一种模式线虫在生命科学的发展过程中发挥着举足轻重的作用。对秀丽隐杆线虫的培养、研究进展等方面进行了简要的综述。     

牛胎儿成纤维细胞的分离培养及转染线虫ω-3脂肪酸去饱和酶基因

为了为核移植法制作转线虫ω-3脂肪酸去饱和酶基因克隆牛提供供体细胞,体外分离培养牛胎儿成纤维细胞并进行了线虫ω-3脂肪酸去饱和酶基因转染。首先采用组织块贴壁法分离培养牛胎儿成纤维细胞,线虫ω-3脂肪酸去饱和酶基因表达载体以脂质法介导转染牛胎儿成纤维细胞,通过G418筛选获得稳定转染的细胞克隆,PCR 鉴定外源基因在细胞基因组中的整合,对阳性克隆进行传代2-3次后利用RT-PCR检测外源基因的转录。结果表明,组织块贴壁后7天可获取原代成纤维细胞,基因转染后利用G418筛选9天即可获得转基因细胞,对转基因细胞进行传代,PCR 检测显示CMV启动子和ω-3脂肪酸去饱和酶基因整合到细胞基因组中,RT-PCR检测显示ω-3脂肪酸去饱和酶基因在转基因传代细胞中得到有效转录。本研究为下一步通过核移植方法获得转基因肉牛提供了条件。     

Some Aspects of Biology and Control Methods of Fruit Stalk Borer Oryctes elegans Prell （Coleoptera： Scarabaeidae）

Laboratory and field studies were conducted on some aspects of biology and control methods of fruit stalk borer Oryctes elegans Prell., the study was conducted in date palm orchards in south Baghdad during the years 2009 and 2010. The laboratory rearing result ofO. elegans indicated that the larval stage period was very long reached 6 months, the body weight of the mature larva was 7.61 gm, the length and body circumference were 7.58 and 5.23 cm respectively. The period of pupa stage was 19 day and 2.97 gm body weight, while the length and body circumference were 3.74 and 3.21 cm respectively .While the weight of adult stage was 1.67 gm and 3.14 cm, 2.71 cm for the length and circumference body respectively. Results of hand collection larvae in palm trees during the regular annual service, showed reduction in population density of adults to 1.4 adult/trap per week compared with 3.3 and 14.0 adult/trap per week in the orchards were larvae collected partially and without hand collection by using the light traps with solar energy （Magna Traps, Russell IPM） respectively. Also, the study proved the existence of an inverse relation between the moon light and adult activity, which affected on the adult number cough in light traps. These results indicated that the hand collection of larvae works during months January, February, March and April at synchronized with the larval stage on palm trees, and use Magna Traps as an effective method to control O. elegans through IPM programs in palm orchards.     

雅脊金小蜂长翅型雌蜂对米象种群的控制作用

雅脊金小蜂Theocolax elegans（West．）是我国南方重要仓储害虫米象Sitophilus oryzae（L．）的优势天敌。为了更好地保护和利用该蜂，采用单因子方差分析和ISD多重比较，在实验室内研究了雅脊金小蜂和米象的种群数量动态，以及该蜂长翅型雌蜂对米象种群的控制作用。结果显示，在温度25℃、相对湿度65％的条件下，雅脊金小蜂和米象的世代发育历期分别约为25天和40天。按照每盒1、2、4、8、16、32、64和128头接入的寄生蜂均可定殖，并对米象种群起着控制作用。其中，接蜂64头时，即寄生蜂与米象数量比为1：6时，控制效果最好，在放蜂后第10-50天内，控制效果迭89．11％-96．47％，与其它几组试验差异显著。试验结果表明，雅脊金小蜂可以有效地控制米象的发生与危害。     

壬基酚溶液暴露对秀丽隐杆线虫的毒性研究

为探究壬基酚溶液暴露对秀丽隐杆线虫的急性致死毒性和非致死毒性效应,将同期化后的秀丽隐杆线虫暴露于壬基酚溶液24 h,考察壬基酚对秀丽隐杆线虫的半致死浓度、性腺臂发育、子代数目、虫体长度和身体弯曲频率等毒性指标的影响。结果表明,以L4期野生型秀丽隐杆线虫为受试生物,对壬基酚溶液24 h的半数致死浓度即LC50值为8.09 mg·L~(-1)。壬基酚暴露干扰了秀丽隐杆线虫性腺臂的正常发育,与对照组相比,0.081 mg·L~(-1)和0.162 mg·L~(-1)染毒组对秀丽隐杆线虫的子代数目和虫体长度均有显著性影响(P0.05);低剂量染毒组身体弯曲频率与对照组相比没有统计学差异(P0.05),而高剂量组与对照组有显著性差异(P0.05)。毒性试验研究表明,模式动物秀丽隐杆线虫对壬基酚的毒性响应比较敏感,在环境激素的生态毒理学研究中具有潜在的应用价值。     

百日草柱头可授性和花粉生活力的研究

 【目的】观察百日草花后柱头的形态变化，测试百日草的柱头和花粉的寿命，为提高百日草的人工授粉效率和杂交育种提供依据。【方法】采用联苯胺－过氧化氢测定柱头可授性、花粉离体萌发试验和田间试验相结合的方法进行研究。【结果】（1）百日草在8:30～16:00开花，花粉生活力为18 h；（2）舌状花柱头保持膨胀，花柱挺立可达7～10 d；（3）联苯胺－过氧化氢测定柱头可授性的结果显示，花后1～3 d可授率为79.9%～83.1%，4～6 d为56.1%～63.0%，7～10 d为37.0～43.3%；（4）丫状时期、丫状尖端稍弯曲时期、柱状时期田间授粉的结实率分别为76.3%、48.5%和36.8%；（5）未经处理的柱头结实率为48.8%，去丫状一裂者为30.9%，去柱头只留花柱者为19.9%。【结论】（1）用联苯胺－过氧化氢方法测定百日草柱头可授性可行；（2）花后2～3 d柱头丫状时期进行人工授粉结实率高；（3）柱头顶端的毛状突起增大了吸收花粉的表面积，有利于授粉结实。