不同荧光染色方法检测HMC毒素诱导处理玉米B37根冠细胞凋亡

采用吖啶橙(AO)与溴化乙啶(EB)荧光双染色以及Hoechst 33258荧光染色法对HMC毒素诱导玉米B37-C、B37-N根冠细胞凋亡率进行检测。结果表明, 采用AO/EB双染色后, 当HMC毒素浓度为50、100、150 μg/mL, 处理7 h时B37-C根冠细胞凋亡率分别为24.8%、58.2%、70.2%, B37-N仅为11.0%、25.7%和36.6%;当浓度为150 μg/mL, 处理时间4 h时B37-C根冠细胞最大凋亡率为62.3%, B37-N为25.8%。经Hoechst 33258染色后, HMC毒素浓度为50、100、150 μg/mL, 处理7 h时B37-C的根冠细胞凋亡率分别为32.5%、58.7%、74.5%, B37-N仅为7.5%、22.3%和30.7%;HMC毒素浓度为150 μg/mL, 处理4 h时B37-C的细胞凋亡率为62.3%, B37-N为19.3%。     

Evaluation of Passive Samplers as a Monitoring Tool for Early Warning of Dinophysis Toxins in Shellfish

From June 2006 to January 2007 passive samplers (solid phase adsorbing toxin tracking, SPATT) were tested as a monitoring tool with weekly monitoring of phytoplankton and toxin content (liquid chromatography–mass spectrometry, LC-MS) in picked cells of Dinophysis and plankton concentrates. Successive blooms of Dinophysis acuminata, D. acuta and D. caudata in 2006 caused a long mussel harvesting closure (4.5 months) in the Galician Rías (NW Spain) and a record (up to 9246 ng·g resin-week⁻¹) accumulation of toxins in SPATT discs. Best fit of a toxin accumulation model was between toxin accumulation in SPATT and the product of cell densities by a constant value, for each species of Dinophysis, of toxin content (average) in picked cells. Detection of Dinophysis populations provided earlier warning of oncoming diarrhetic shellfish poisoning (DSP) outbreaks than the SPATT, which at times overestimated the expected toxin levels in shellfish because: (i) SPATT accumulated toxins did not include biotransformation and depuration loss terms and (ii) accumulation of toxins not available to mussels continued for weeks after Dinophysis cells were undetectable and mussels were toxin-free. SPATT may be a valuable environmental monitoring and research tool for toxin dynamics, in particular in areas with no aquaculture, but does not provide a practical gain for early warning of DSP outbreaks.     

云南常见鹅膏毒素粗提物对几种植物病原真菌的抑制活性研究

研究了白刺头鹅膏、土黄鹅膏、隐花青鹅膏、红黄鹅膏和格文鹅膏甲醇提取物对3种植物病原真菌菌丝生长的抑制作用。结果表明:土黄鹅膏和白刺头鹅膏毒素粗提物对烟草赤星病菌(Alternaria alternate)、魔芋软腐病菌(Rhizopus stolonifer)、蚕豆基腐病菌(Fusarium avenaceum)菌丝生长的抑制作用较强,EC50为13.2138~25.7256 g/L;其他3种鹅膏甲醇提取物对上述3种真菌菌丝生长的抑制作用很弱。     

玉米弯孢菌毒素理化性质及致病机理的研究

对玉米弯孢菌产生毒素的理化性质和致病机理进行了初步研究。结果表明:毒素的化学成分包括蛋白质和可溶性糖;毒素对不同玉米自交系种子萌发和叶片致萎程度的影响有明显差异,研究结果与弯孢菌对不同抗性自交系的致病能力基本一致。     

玉米弯孢菌毒素培养条件的研究

研究了玉米弯孢菌产毒能力与培养条件、环境因子等因素的关系.结果表明:不同菌株的产毒能力存在明显差异,以CL-1、CL-2、CL-7、CL-13菌株培养液对叶片的破坏能力最强;该病原菌在Fries培养基中有较强的产毒能力;培养基中以蔗糖为碳源、以KNO3为氮源较适合毒素的产生;在25 ℃条件下培养20～25 d产毒能力较强;光照对毒素的产生没有明显的影响;其中培养方式对毒素的产生有较大的影响,振荡培养有利于毒素的产生.     

尖孢镰刀菌毒素对大豆幼根生理生化的影响

用尖孢镰刀菌毒素处理大豆幼根后,测定其幼根的根活力,细胞渗透性,蛋白质、可溶性糖和脯氨酸含量。结果表明:F.oxysporum毒素对大豆幼根具有强烈的毒害作用,降低大豆根系活力;细胞膜透性增大,且随处理时间的延长和毒素浓度的增加而增大;毒素处理后,前期6h内抗病品种幼根内蛋白质含量降低,感病品种蛋白质含量上升,12h后抗病和感病品种蛋白质含量都降低;抗、感品种的幼苗根系可溶性糖含量明显降低;脯氨酸含量明显增高,感病品种上升的幅度大于抗病品种。     

禾谷镰刀菌粗毒素的生物活性及其在小麦品种抗赤霉病性鉴定中的应用

 用小麦黄化芽鞘生物测定法探测禾谷镰刀菌粗毒素的生物活性，以及不同抗性小麦品种对粗毒素的反应。以纯脱氧雪腐镰刀菌烯醇（DON）作比较，证明了粗毒素具有与纯毒素DON相同的生物活性。对粗毒素在抗赤霉病性鉴定应用的初步探讨中，明确了小麦品种对粗毒素的敏感性与其在田间的抗赤霉病性呈负相关。     

赤霉毒素对小麦幼胚愈伤组织和幼苗生长的影响

研究了赤霉毒素对小麦幼胚愈伤组织和幼苗生长的影响.结果表明,赤霉毒素对小麦幼胚愈伤组织有毒害和致死作用;赤霉毒素使小麦种子发芽率、幼苗的株高、根长、发芽指数、活力指数及根系还原力和可溶性糖含量降低,并使电导率值升高.     

茄子黄萎病菌毒素液对茄种子发芽及幼苗生长的毒害作用

试验用Czapek′s培养液培养茄子黄萎病菌 (Verticilliumdahliae) ,经过滤、离心和透析 ,分别得到其培养滤液、粗毒素液。测试了培养滤液对茄子抗、感病品种种子发芽、根生长的毒害作用及粗毒素对茄幼苗的致萎作用。结果表明 ,茄黄萎病菌毒素液对茄种子发芽、根的生长及幼苗都有一定的毒害作用     

Host range and phytotoxicity of <Emphasis Type="Italic">Stemphylium solani</Emphasis>, causing leaf blight of garlic (<Emphasis Type="Italic">Allium sativum</Emphasis>) in China

Since 2004, a new leaf blight disease on garlic of high severity has been observed in Dangyang County, Hubei province, China. Initial symptoms consisted of multiple, small, irregular to oval, white leaf spots, which enlarge to produce sunken purple lesions, sometimes surrounded by a bright yellow margin. As the disease progressed, lesions expanded and merged, resulting in withering of leaf tips. After isolation and pathogenicity testing, the causal agent of leaf blight of garlic was identified as Stemphylium solani from cultural and morphological characteristics, and subsequent analysis of the internal transcribed spacer region of ribosomal DNA. When fungal plugs of two S. solani isolates were inoculated onto 11 garlic cultivars and 20 other crop species, leaf spots appeared on all inoculated plants, but two garlic cultivars (Qingganruanye and Ruanruanye) and three crop species (Capsicum annuum, Brassica napus and Amaranthus mangostanus) showed the smallest leaf spots. In cross-inoculation experiments, no indications of host specificity were observed, but S. solani isolated from garlic was generally the most virulent on five plant species, while the isolate from leek (Allium odorum) was generally the least virulent. Toxicity testing of the crude culture filtrates indicated that garlic isolates produced toxin(s) that were not heat-labile and induced different levels of phytotoxicity toward various garlic cultivars and crops.