ITS—RFLP分析进行昆虫病原线虫斯氏属和异小杆属的分类鉴定

本研究通过PCR扩增和六种限制性内切酶（AluⅠ，HinfⅠ，MboⅠ，RsaⅠ，HaeⅢ和PvuⅡ）酶切，对国内害虫防治上常用的几种昆虫病原线虫，包括斯氏属S.car-pocapsae,S.feltiae和S.glaseri以及异小杆属H.bacteriophora,H.zealandica,H.indicus和H.megidis等8个品系rDNA-ITS进行分析。建立起可以区分各线虫种的标准RFLP图谱。该方法快速简便，稳定可靠，需要的样品量少。可以用于新鲜的，或冻存的样品，甚至分析单条的线虫，不仅可进行昆虫病原线虫的快速分类鉴定。而且进一步可以应用于线虫田间释放的辅助监测。实际田间感染率的测定和线虫毒力的比较。     

水稻不同品种或组合对甲磺隆耐药性差异的机制研究

以水稻乙酰乳酸合成酶(ALS)比活力为研究对象,通过在离体和活体条件下比较其对甲磺隆的敏感性水平,探讨了水稻不同品种或组合的耐药性差异机制。结果表明,离体条件下不同水稻品种或组合ALS对甲磺隆均较敏感,当甲磺隆浓度为100 μg/L时,对ALS比活力抑制率达60%以上,且活力百分比与甲磺隆浓度对数成直线负相关关系,相关程度显著或极显著;活体条件下ALS活力均受到甲磺隆不同程度的抑制,但同一品种ALS活力不随甲磺隆浓度的变化而呈现规律性变化。在甲磺隆浓度相同时,活体条件下所有供试水稻品种ALS活力均显著高于离体条件下的ALS活力,影响程度与植株耐药性差异基本一致,说明甲磺隆在水稻体内存在较强代谢失活作用,代谢失活差异是水稻不同品种或组合对甲磺隆的耐药性差异机制。     

农作物病虫预报可视化发展与应用前景

农作物病虫预报可视化具有形象生动、信息传递快捷、覆盖面广等优点,是更好发挥预报作用的最佳方式。大范围实施这种预报发布形式的条件,目前已基本成熟,经过努力,必然会在不长的时间内取得长足进展。     

根结线虫的研究现状

概述了根结线虫的发生分布和传统分类鉴定,以及分子生物学技术(同工酶电泳技术、DNA重组技术、PCR技术)在根结线虫种和生理小种鉴定中的运用及其防治,并对生物防治及抗根结线虫育种、转基因工程在植物线虫学研究领域上的应用前景作了展望。     

山羊高床舍饲配套饲养技术探讨

山羊高床舍饲技术通过修建标准化山羊圈舍，实现山羊饲养过程中对山羊个体的有效控制和辅助，降低饲养劳动量和劳动强度；通过带动种草养羊、养羊与沼气结合，在实现山羊饲养的同时，促进了退耕还草、封山育林等生态建设项目的实施。     

草酸青霉菌果胶酶诱导黄瓜抗黑星病研究

 本文就草酸青霉菌(Penicillium oxalicum)的固态发酵提取产物--果胶酶粗酶液诱导黄瓜对黑星病(Cladosporium cucumerinum)的抗性进行了研究。以果胶酶粗酶液喷雾处理4个感黑星病黄瓜品种的黄化苗,48 h后挑战接种黑星病菌孢子悬液,其中"中农5号"黄瓜品种表现的诱导抗病效果最好,诱抗效果达62.51%。不同浓度果胶酶诱导处理黄瓜,发现果胶酶浓度在20 U/mL时,可导致黄瓜发病略高于对照;在40~200 U/mL浓度范围内,诱导效果较为明显。通过研究果胶酶诱导抗病的时效性,表明诱导处理前接种病菌或诱导处理后0、6 h接种的各处理病情指数与对照间没有差别,而诱导处理12~72 h后接种病菌的,果胶酶的诱导抗病效果均很明显,诱抗效果达29.64%~60.02%。实验还表明,随着挑战接种压力的增大,果胶酶的诱导抗病效果降低。果胶酶不能抑制黑星病菌孢子萌发,相反可以促进孢子萌发和芽管生长。     

黄瓜花叶病毒丹参分离物的鉴定和外壳蛋白基因序列分析

 丹参(Salvia miltorrhiza Bge.)为唇形科鼠尾草属草本植物,以根入药,是我国一种常用大宗中草药。近年来河北安国中药材基地丹参上一种退化病十分严重,该病田间发病率高,有的田块高达60%~80%,表现为花叶、斑驳、卷叶、黄化、矮化等症状,严重影响了丹参的产量和品质。我们利用生物学、电镜观察、血清学方法和基因序列测定等方法对病原进行了初步研究,发现黄瓜花叶病毒(Cucumber mosaic virus,CMV)与该病害密切相关     

Antitumor effect of chlorophyllin in vitro

AIM: To study the effect and mechanism of chlorophyllin (CHL) inhibiting HT29 cells. METHODS: IC₅₀ value and growth curve of HT29 cells were detected with MTT method. Apoptosis was detected with Wright-Giemsa staining, FCM and DNA electrophoresis. Telomerase was detected by PCR-ELISA, and protein and mRNA expression of COX-2 gene were detected through RT-PCR and Western blot. RESULTS: CHL inhibited the growth of HT29 in a dose-dependent manner. CHL blocked HT29 cells in G₁ phase but did not induce apoptosis. Different concentration of CHL inhibits the expression of telomerase and COX-2 in HT29 cells. CONCLUSION: CHL inhibited the growth of HT29 cells by inhibiting the expression of telomerase and COX-2 and blocking cells in G₁ phase.     

Effect of homocysteine on expression of interleukin-8 mRNA and protein in THP-1 macrophages

AIM: To investigate the effect of homocysteine (Hcy) on expression of interleukin-8 (IL-8) mRNA and protein in THP-1-derived macrophages (THP-1 macrophages). METHODS: Cultured THP-1 monocytes were induced to macrophages by 0.1 μmol/L PMA treatment for 72 hours, then the differentiated THP-1 macrophages were incubated with homocysteine (0.01 mmol/L-0.20 mmol/L) for 24 hours, or with 0.10 mmol/L Hcy for various time up to 48 hours. IL-8 protein in THP-1 supernatants was measured by ELISA, and IL-8 mRNA expression was detected by semiquantitive RT-PCR. RESULTS: Compared with control, Hcy significantly increased the expression of IL-8 protein in a concentration-dependent manner. 0.05 mmol/L, 0.10 mmol/L and 0.20 mmol/L Hcy increased IL-8 production by 1.28 fold, 1.32 fold and 1.55 fold, respectively (P＜0.01). IL-8 production were elevated significantly 3 h after treatment with 0.10 mmol/L Hcy. In addition, Hcy also increased IL-8 mRNA expression in a concentration-and time-dependent manner. CONCLUSION: Hcy may contribute to atherogenesis by inducing IL-8 expression and secretion in THP-1 macrophages.     

金龟子绿僵菌固态培养生物变量优化研究

金龟子绿僵菌属于真菌类生物杀虫剂,本文研究了接种量、种龄、菌种代数等生物因素对金龟子绿缰菌生长及产孢量的影响,并对液—固两步发酵工艺进行了研究。经过优化,得到金龟子绿僵菌产孢的最佳生物参数是:接种量为2.5g/100g、种龄为5-6天;采用固体二代种,培养6天,孢子产量可达1.531×10~(10)孢子/g干培养基。