中药复方对H9N2亚型禽流感病毒在MDCK细胞增殖的作用

为了筛选对H9N2亚型禽流感病毒（Avian influenza virus,AIV）有独特防治效果的中药复方,本试验基于禽流感发病临床症状、结合中药复方用药基本原则,组方芩根提取液（Qingen extract,QG）,以奥司他韦（达菲,DF）为阳性对照药,通过研究药液对神经氨酸酶（neuraminidase,NA）的抑制作用,采用CCK-8法测定药液对犬肾上皮细胞（MDCK）毒性作用,并从病毒吸附、增殖和灭活3个方面做了药效评价。结果表明,QG对NA的抑制作用在一定浓度范围内呈浓度依赖性增高,半数抑制浓度（IC₅₀）约为1 130 μg/mL;QG和DF的最大安全浓度分别为2 500和500 μg/mL,H9N2 AIV的TCID₅₀为10^-4.36/100 μL;QG浓度为156.25~2 500 μg/mL范围内,对H9N2 AIV的病毒毒力有一定抑制作用,并在MDCK细胞上呈现出一定的抗吸附、抑制病毒复制作用。表明QG在对抗H9N2 AIV的NA活性、抑制H9N2 AIV吸附靶细胞和在细胞内复制有一定的作用。     

利用Tild-CRISPR/Cas9定点编辑荷斯坦种公牛的无角Pc位点

试验旨在利用Tild-CRISPR/Cas9系统介导的同源重组技术制备纯合无角种公牛细胞系。针对控制无角性状的Pc靶位点设计sgRNA,T7E1酶切和测序检测突变效率;以pUC57为骨架连接Pc片段及其两侧约800 bp的同源序列左臂（L）和右臂（R）,双酶切获得同源重组片段后与sgRNA共同转染至荷斯坦种公牛耳缘成纤维细胞中,筛选获得单细胞克隆并鉴定。结果显示,试验成功构建了6个sgRNA_（1-6）,并筛选获得了突变效率最高的sgRNA₁,其突变效率为32.6%;成功获得了长度为1 901 bp基因序列完全正确的同源重组片段;共获得147个单细胞克隆,其中8个单细胞克隆发生正确的单等位Pc位点插入,1个单细胞克隆发生正确的双等位Pc位点插入。外源基因残留检测结果显示,单细胞克隆没有Cas9基因残留,可作为后续克隆生产优秀无角纯合胚胎的核供体细胞。本研究成功利用Tild-CRISPR/Cas9定点编辑的方法获得了Pc位点纯合插入的无外源Cas9基因残留的无角牛耳缘成纤维细胞系,为将来优秀无角体细胞克隆种公牛的培育以及主要功能基因研究提供了良好的材料储备和技术平台。     

H9N2亚型禽流感病毒与其他病原混合感染的研究进展

H9N2亚型禽流感病毒（Avian influenza virus,AIV）属于低致病性AIV,但因其分布广泛、传播迅速,可引起感染家禽生产性能下降,给家禽业带来了极大的经济损失。H9N2亚型AIV在感染家禽过程中可引起严重的免疫抑制,使家禽极易继发上呼吸道细菌、消化道细菌等感染,从而导致H9N2亚型AIV致病力增强,细菌黏附定植能力增强,家禽死亡率显著升高。另外,H9N2亚型AIV还能与禽传染性支气管炎病毒、禽传染性法氏囊病病毒、新城疫病毒等发生混合感染,病毒入侵时有可能出现协同作用或颉颃作用,从而相互促进或抑制病毒的复制和排毒;H9N2亚型AIV还极易发生突变或与其他亚型流感病毒在混合感染时发生基因重组产生感染人的新亚型毒株,给人类健康和公共卫生安全带来重大威胁。作者综述了H9N2亚型AIV与其他病原混合感染的研究进展,通过阐述H9N2亚型AIV与细菌或病毒混合感染的协同或颉颃作用,以期为临床上H9N2亚型AIV混合感染的防治提供参考。     

巴西陆稻IAPAR9生产潜力与高产栽培初探

专题攻关与综合试验研究结果表明 :巴西陆稻 IAPAR9在扬州丘陵地区有较好的适应性与丰产性。在播种期除补充必要的少量水外 ,可利用生长季自然水 ,达到单产 6750～ 750 0 kg/hm2 的生产潜力。试验研究还表明 ,适时早播、适当稀植促大穗、严防杂草和螟虫危害是夺取本地区巴西陆稻高产关键     

保护地番茄新品种中杂101的选育

中杂101番茄是以002-64为母本,以002-69为父本配制的一代杂种。植株无限生长,节间长,长势强,中早熟。幼果有绿果肩,成熟果粉红色,单果质量200g左右,果皮厚,较耐运输;高抗叶霉病和ToMV,抗黄萎病和CMV,中抗南方根结线虫。适于日光温室和早春大棚等保护地栽培,一般每667m2产量7000kg左右。     

Occurrence of fimbriae and enterotoxins in Escherichia coli strains isolated from piglets in Poland.

1125 and 1146 E. coli strains isolated from suckling and weaned piglets with diarrhea, respectively, and 724 strains from healthy piglets were tested for the presence of fibriae and production of enterotoxins. The fimbriae were determined by hemagglutination and slide agglutination tests, enterotoxins—by the use of ileal loop test in piglets (LT and STb enterotoxins) and suckling mouse assay (STa enterotoxin). It was found that 72.8 and 53.0% strains, isolated from diseased suckling and weaned piglets, respectively, possessed specific fimbrial hemagglutinins, in most cases with K88 antigen. Additionally, 987P fimbriae were detected in 14.0 and 0.7% strains isolated from piglets with diarrhea. Only 5 strains (0.7%) recovered from healthy piglets had specific fimbriae, usually with undetermined antigenic structure. F1 fimbriae (called common or unspecific) were found in strains isolated both from diseased (15.2 and 16.3% strains, respectively) and healthy piglets (27.1% strains). It was noted that the strains isolated from suckling and weaned piglets with diarrhea in most cases were enterotoxigenic (90.5 and 69.1% strains, respectively) and most frequently produced heat-labile toxin LT alone or with STb. 18.5% of enterotoxigenic strains isolated from healthy piglets produced STa toxin.     

Evaluation of transgenic event CBH 351 (StarLink) corn in broiler chicks

The influence of transgenic event CBH 351 (StarLink; SL)-derived hybrid corn on the growth performance, health condition and physiological function in broiler chicks, as well as the possible transfer of the cry9C gene and Cry9C protein to blood, liver and muscle were examined in comparison with chicks fed on a diet with non-transgenic corn (SL-F). Bodyweight gain and feed conversion ratio in the chicks fed on a diet with SL were significantly greater than in chicks fed on a diet with SL-F during the starter phase (0–3 weeks of age), but this significant difference disappeared during the finisher phase (4–7 weeks of age). No abnormalities in health condition in either SL or SL-F groups were observed, and livability did not differ significantly between SL and SL-F groups. Moreover, no significant differences in serum biochemical and hematological values, histopathological observation and necropsy findings were observed between SL and SL-F groups at the end of the experiment. The cry9C gene and Cry9C protein were not detected in blood, liver and muscle of chicks at 3, 5 or 7 weeks of age. The results indicate that feeding SL does not influence growth performance, health condition or physiological function in broiler chicks, and the cry9C gene and Cry9C protein are not transferred to the blood, liver and muscles of broilers.     

弱分枝西瓜wbl9的选育与初步应用

用具有弱分枝性状的wbl1作供体亲本,用优良的西瓜自交系015作父本,通过1次杂交、2次回交和连续6代的自交分离和纯化,育成了具有弱分枝性状的优良自交系wbl9。该自交系既保持了wbl1的弱分枝特性,又克服了wbl1不易坐果和品质与抗性较差的缺点,具体特征如下:平均每株含子蔓2.4个,种植可不整枝,省工省力;单株坐果0.93个,易坐果;果实圆形,单果重5～6kg,果实发育期31～33d;果皮绿色,上有墨绿色细齿带,薄而韧,耐储运;瓜瓤鲜红,质脆,中心可溶性固形物含量10.5%;田间抗性表现与015相近,但明显优于wbl1。用该自交系作亲本选育的新组合TH0401和TH0404综合性状表现优秀。结果表明,wbl9不仅可作为亲本材料直接应用,还可用作选育新弱分枝自交系的基础材料。     

大穗大粒冬小麦品种中麦9号的选育与推广

中麦 9号由中国农业科学院作物所麦类系高肥组以泗阳 936为母本、83鉴 2 5为父本 ,采用系谱法选育而成。北京农学院遗传育种研究所参与了示范和推广工作 .该品种具有矮杆、茎杆粗壮坚韧、抗倒伏、抗寒性较强、大穗大粒、综合农艺性状好、增产潜力大等突出特点。中麦 9号 1997年通过北京市和河北省审定 ;1998年通过全国审定 ,并被列入河北省十大推广品种 ;1999年获北京市科协金桥工程三等奖 .1996- 2 0 0 0年累计推广面积 10 0多万hm2 .     

优质高产糯玉米新品种渝糯9号选育

糯玉米杂交种渝糯9号是重庆市农科院以3469为母本,以S181为父本选育而成的。该品种具有品质优、产量高、中早熟、适应性广等特点,于2004年通过重庆市审定。