土壤中南方根结线虫的实时荧光PCR检测和定量

为了准确测定土壤中南方根结线虫Meloidogyne incognita的群体密度,根据序列特异性扩增区标记设计了南方根结线虫特异性引物和TaqMan探针,分别建立了卵和2龄幼虫的实时荧光PCR定量检测体系,并将该检测体系与显微镜计数法进行了比较.结果表明,引物Mi-F/R及探针Mi-probe对南方根结线虫具有高度特异性,建立的标准曲线循环阈值与卵和2龄幼虫数量的对数值之间具有良好的线性关系,相关系数分别为0.9771和0.9853,扩增效率均为90％,检测灵敏度为10-1个卵及10-3条2龄幼虫;对10个田间土壤样本的检测显示,实时荧光PCR定量检测与显微镜计数法测定的南方根结线虫卵和2龄幼虫数量呈显著正相关,且两种方法对2龄幼虫的测定结果无显著差异.     

大白熊犬

一、大白熊犬的历史大白熊犬(Great Pyre-nees),别名比利牛斯山地犬(Pyrenean Mountain Dog),它最早的化石在欧洲被发现于青铜器时代,约公元前1800至1000年。先是在法国和西班牙交界的比利牛斯山区牧羊,后来成了法国皇室的高贵犬种,早在18世纪就已经生活在法国宫廷。但人们相信     

Low levels of haptoglobin and putative amino acid sequence in Taiwanese Lanyu miniature pigs

Porcine haptoglobin (Hp) is an acute phase protein. Its plasma level increases significantly during inflammation and infection. One of the main functions of Hp is to bind free hemoglobin (Hb) and inhibit its oxidative activity. In the present report, we studied the Hp phenotype of Taiwanese Lanyu miniature pigs (TLY minipigs; n=43) and found their Hp structure to be a homodimer (beta-alpha-alpha-beta) similar to human Hp 1-1. Interestingly, Western blot and high performance liquid chromatographic (HPLC) analysis showed that 25% of the TLY minipigs possessed low or no plasma Hp level (<0.05 mg/ml). The Hp cDNA of these TLY minipigs was then cloned, and the translated amino acid sequence was analyzed. No sequences were found to be deficient; they showed a 99.7% identity with domestic pigs (NP_999165). The mean overall Hp level of the TLY minipigs (0.21 +/- 0.25 mg/ml; n=43) determined by enzyme-linked immunosorbent assay (ELISA) was markedly lower than that of domestic pigs (0.78 +/- 0.45 mg/ml; p<0.001), while 25% of the TLY minipigs had an Hp level that was extremely low (<0.05 mg/ml). In addition, the initial recovery rate (first 40 min) in the circulation of infused fluorescein isothiocyanate (FITC)-Hb was significantly higher in the TLY minipigs with extremely low Hp levels than those with high levels. This data suggests that the low concentration of Hp-Hb complex is responsible for the higher recovery rate of Hb in the circulation. TLY minipigs have been used as an experimental model for cardiovascular diseases; whether they can be used as a model for inflammatory diseases, with Hp as a marker, remains a topic of interest. However, since the Hp level varies significantly among individual TLY minipigs, it is necessary to prescreen the Hp levels of the animals to minimize variation in the experimental baseline. The present study may provide a reference value for future use of the TLY minipig as an animal model for inflammation-associated diseases.     

龙岩地区部分猪场弓形虫病的血清学调查

通过间接血凝(IHA)试验对采自龙岩地区12个猪场的2055份猪血清进行弓形虫病的抗体检测,结果表明猪弓形虫病在龙岩地区呈散发性流行。样品阳性率为5.99%,各猪场之间的抗体阳性率有一定差异,最高为16.22%,最低为0。在母猪群中随着胎次的增加,弓形虫病抗体阳性率也升高,由1～2胎的6.72%上升到5胎以上的12.18%;育肥猪群总体弓形虫病抗体阳性率较低,由哺乳仔猪的10.94%缓慢降至育肥猪的1.62%,呈现出随日龄增加弓形虫病抗体阳性率逐渐降低的趋势。     

24个白桑(Morus alba L.)地方品种的遗传多样性分析

采用ISSR分子标记技术对山东、河北地区的24个白桑(Morus alba L.)地方品种资源进行了遗传多态性分析。筛选的13条ISSR引物共扩增86条扩增带,其中多态性条带63条,多态性比率为73.25%,ISSR标记遗传相似系数范围在0.6706~0.9529。通过类平均聚类(UPGMA)法分析,24份材料聚分为2大类。     

Screening of cold-resistant seedlings of a Chinese wild grape (Vitis piasezkii Maxim var. pagnucii) native to loess plateau of eastern Gansu province,China, as rootstocks

Seedlings of a Chinese wild grape (Vitis piasezkii Maxim var. pagnucii) native to loess plateau of Eastern Gansu province, China, were evaluated to screen cold-resistant rootstocks in Lanzhou area. After 14-year investigation two selections of LDP-191and LDP-294 were screened as rootstocks for two table grape cultivars, ‘Fujiminori’ and ‘Red Globe’, respectively. The two graft unions demonstrated very high cold-resistance as well as good graft compatibility. Furthermore, they could survive through low temperatures in winter without soil coverage together with good fruit quality of the cultivars grafted.     

过瘤胃氨基酸在奶牛生产中的应用

本文综述了过瘤胃氨基酸的概念、稳定性、保护效果的测定方法及过瘤胃氨基酸对奶牛生产性能的影响和影响过瘤胃氨基酸效果的因素。     

遮光及复光处理对紫叶狼尾草叶色及生理变化的影响

为探寻光照对紫叶狼尾草（Pennisetum setaceum ‘Rubrum’）的叶色及生理变化的影响,以自然光为对照,用透光率为10%的遮阳网对其进行遮光处理,直至新叶成熟完全变绿后,撤去遮阳网用自然光进行复光处理,而后测量各阶段的叶色参数和相关生理指标的动态变化。结果显示,遮光后紫叶狼尾草新叶为绿色,叶色参数L、b值显著增加,a值显著减少;生理指标叶绿素a、叶绿素b含量显著增加,花色素苷、类黄酮、可溶性糖含量和苯丙氨酸解氨酶（phenylalnine ammonialyase,PAL）、查尔酮异构酶（chalcone isomerase,CHI）活性显著减少,PPO多酚氧化酶（polyphenol oxidase,PPO）、过氧化物酶（peroxidase,POD）活性无明显变化。复光处理后,叶色逐渐转紫,叶色参数变化与遮光相反;生理指标变化与遮光后减少或增加的指标呈相反趋势,PPO、POD活性变化不明显。     

不同轮作模式下小麦禾谷孢囊线虫的发生动态和种群密度

轮作是防治小麦禾谷孢囊线虫的重要农业措施,为了明确青海省春麦区不同轮作模式对小麦禾谷孢囊线虫的控制效果,采用田间大区试验法对生产中应用的6种轮作模式进行了研究。结果表明:不同轮作模式下,小麦禾谷孢囊线虫种群密度变化差异极显著,其中小麦与马铃薯、油菜、蚕豆轮作两年或以上能有效降低小麦禾谷孢囊线虫种群密度,土壤中的孢囊量减少39.31%~84.39%,单孢虫口数量减少73.21%~95.35%,虫口密度减少83.76%~97.82%;不同作物间,小麦与马铃薯或蚕豆的轮作效果(虫口密度减少74.39%~79.37%)显著优于小麦与油菜的轮作效果(虫口密度减少67.16%)。在同一地块相同条件下,种植油菜、蚕豆、马铃薯、小麦4种作物,小麦禾谷孢囊线虫均能正常孵化,4月底土壤中的2龄幼虫(J2)量增加,5月上旬达到高峰期,5月中旬开始,土壤中的J2、孢囊量、虫口密度和单孢虫口数量均急剧下降,6月至7月份下降幅度小,趋于稳定;田间空孢囊率于5月中旬至6月中旬急剧增加,7月份趋于稳定,8月份以前,4种作物田禾谷孢囊线虫的孵化动态和种群密度变化趋势一致,8月中旬,小麦田随着新孢囊脱落到土壤中,禾谷孢囊线虫种群密度开始上升,小麦收获后土壤中的孢囊量比播种前增加28.62%,虫口密度增加41.30%;而油菜、蚕豆、马铃薯田土壤中的孢囊量比播种前减少32.27%~48.36%,虫口密度减少70.91%~81.73%,8月中旬至10月份小麦田禾谷孢囊线虫种群密度极显著高于油菜、蚕豆、马铃薯田。