防霉剂对霉菌和食用菌菌丝生长的影响

试验证明，不同防霉剂对不同霉菌有不同的抑制作用，对食用菌菌丝生长的影响也不同，广谱抑菌的富马酸二甲酯(DMF)是一种较好的食用菌防霉剂。     

二甲基甲酰胺对家蚕毒性试验

二甲基甲酰胺对家蚕的毒性较低，只有在很高的浓度食下时才表现出急性中毒死亡，并且随着龄期的增加，家蚕的耐毒性增加，3龄蚕比2龄蚕有更强的耐毒性。低浓度的二甲基甲酰胺（DMF）对家蚕生命率和经济性状都没有显著影响。DMF对家蚕的毒性有积累作用，3龄期连续添毒稀释10倍的DMF原液24h没有观察到急性中毒死亡，但连续添毒90h后，可最终导致家蚕中毒死亡。     

Effect of dimethyl sulfoxide on endotoxin -induced fever in rabbits

AIM:To investigate the effect of dimethyl sulfoxide on endotoxin -induced fever in rabbits. METHODS:Test substances were administered intravenously into a marginal ear vein. Temperature responses were measured using rectal thermistor probes. RESULTS:Endotoxin (0.4 μg/kg) stimulated a biphasic rise in colonic temperature. Pretreatment with dimethyl sulfoxide significantly attenuated the biphasic febrile response to endotoxin (0.4 μg/kg) of conscious rabbits in a dose-dependent manner. Rabbits treated with dimethyl sulfoxide 10 min after injection of endotoxin developed fever, which was significantly milder compared with rabbits treated with an equal volume of normal saline. No significant differences were found between thermal response index of rabbits injected with dimethyl sulfoxide and those with normal saline. CONCLUSION:Dimethyl sulfoxide inhibit endotoxin-induced fever in rabbits.     

不同浓度配比的PEG、二甲基亚砜和水杨酸引发对玉米种子抗寒性的影响

以玉米杂交种创奇518新种子为材料,以不同浓度配比的聚乙二醇（PEG）、二甲基亚砜和水杨酸组合作为引发剂,采用L₉（3⁴）正交试验设计,通过低温种植处理,研究提高玉米种子抗寒性的3种引发剂的最佳浓度配比。结果表明,不同配比引发处理的玉米种子发芽势、发芽率、苗鲜重、活力指数、过氧化物酶（POD）和过氧化氢酶（CAT）活性均表现出明显差异。以浓度为20%的PEG、浓度为0.5%的二甲基亚砜和浓度为0.007%的水杨酸组合处理种子的发芽率、活力指数最高,幼苗长势整齐一致,POD和CAT较对照有明显提高。     

商陆不同极性、根和茎提取物的抑菌性能分析

为探究商陆不同极性、部位提取物的抑菌性能,本实验分别从商陆根和茎中提取石油醚相、乙酸乙酯相、正丁醇相和水相4种不同极性的提取物,再采用滤纸片法测量提取物对大肠杆菌（Escherichia coli）、金黄色葡萄球菌（Staphyloccocus aureus）、巨大芽孢杆菌（Bacillus megaterium）和副溶血弧菌（Vibrio parahaemolyt-icus）4种细菌的抑制性能。结果表明,部分商陆的提取物有一定的抑菌活性,如根正丁醇相对巨大芽孢杆菌和副溶血弧菌,茎水相对副溶血弧菌的抑菌圈在10mm以上,但总体上商陆的提取物的抑菌性能远不及头孢氨苄好。实验还发现商陆抑菌活性最强的物质大都存在于根中,且抑菌活性最强的物质大都存在于水和正丁醇这种极性较高的溶剂的提取物中,不同提取物对不同细菌的抑菌活性情况不一致。因此本研究结果可以为商陆提取物抑菌性能的进一步探索提供参考。     

秋水仙素和二甲基亚砜诱导矮败小麦孤雌生殖的效应

在隔离区内，以矮败小麦轮回选择群体中的不育株为供试亲本，用秋水仙素（Ｃｏｌ）和二甲基亚砜（ＤＭＳＯ）诱导孤雌生殖。结果表明，Ｃｏｌ和ＤＭＳＯ均具有诱导不育株孤雌生殖的作用，并且二者之间存在极显著的互作效应。同一药剂不同的诱导方法，其诱导效果有差异；小穗剪颖处理的孤雌生殖结实率较高；处理时间和套袋与否对孤雌生殖结实率影响不显著。孤雌生殖纯系在纯度和遗传稳定性方面均接近于对照品种（丰抗８号）。从遗传理论和育种实践的角度，讨论了药物诱导矮败小麦孤雌生殖的可行性及在小麦育种中的应用价值     

磷化氢杀虫机理研究综述

系统地综述了对储粮熏蒸剂磷化氢(PH3)的研究结果，从PH3的各种特性和杀虫机理两个方面入手，收集了各种研究试验结果。特性方面重点介绍PH3的物理、化学性质、对人的毒性、熏蒸后的残留与分解等知识。杀虫机理方面介绍了PH3进入昆虫体内的途径，PH3作用在害虫体内的耙标部位，研究结果表明，PH3作用于多种酶，但是，作用于各种酶分子上的靶标部位不详，对害虫的作用机理还未形成一致的结论。本文最后建议开展PH3与昆虫体内蛋白质二硫键的作用研究，希望揭示杀虫机理，供基层技术人员在实际熏蒸杀虫工作中参考。     

Influence of thiosulfate on nitrification,denitrification, and production of nitric oxide and nitrous oxide in soil

Thiosulfate and CS₂ inhibit nitrification. The effect of the addition of thiosulfate on the turnover of inorganic N compounds was tested in an Egyptian and a German arable soil under nitrifying and denitrifying conditions. For nitrification, the soils were amended with NH _inf4 ^sup+ and incubated under aerobic conditions. For denitrification, the soils were amended with NO _inf3 ^sup- and incubated under anaerobic conditions. In both cases, the thiosulfate decreased with time while tetrathionate accumulated to an intermediate extent. Both compounds disappeared completely after <25 days. Production of CS₂ was not observed. Carbonyl sulfide was produced only in the Egyptian soil, but production decreased with increasing amounts of added thiosulfate. Under nitrifying conditions, the addition of increasing amounts of thiosulfate (25, 50, and 100 g S g^-1 dry weight) resulted in decreasing rates of NH _inf4 ^sup+ oxidation to NO _inf3 ^sup- ; it also resulted in an increasing intermediate accumulation of NO _inf2 ^sup- and NO, and in an increasing production of N₂O. Under denitrifying conditions, the addition of increasing amounts of thiosulfate did not significantly affect the rate of NO _inf3 ^sup- reduction, and resulted in an increasing intermediate accumulation of NO _inf2 ^sup- and of NO only in the German soil in which the production of N₂O was slightly inhibited by thiosulfate. These results demonstrate that the nitrification of NH _inf4 ^sup+ and NO _inf2 ^sup- was inhibited by increasing concentrations of thiosulfate and/or tetrathionate without involving the formation of volatile S compounds as potential nitrification inhibitors. Denitrification was not affected by the addition of thiosulfate.     

血根碱抗水霉菌体外活性研究

采用测OD值和琼脂稀释法,以孔雀石绿、氯化钠作为对照,分别进行了3种药物对水霉菌孢子和菌丝的体外抑菌活性研究,其中血根碱以2%DMSO(二甲亚砜)为溶剂,孔雀石绿和NaCl均以水为溶剂。结果表明:血根碱对水霉孢子的MIC80为200μg/mL,对菌丝的MIC为256μg/mL;孔雀石绿对水霉菌孢子的MIC80为6μg/mL,对菌丝的MIC为12μg/mL;氯化钠对水霉菌孢子的MIC80为15 000μg/mL,对菌丝的MIC为20 000μg/mL,说明血根碱具有开发为抗水霉菌药物应用于渔药领域的前景。