利用专利微生物治理硝基苯和苯胺混合废水

利用专利微生物菌种,采用兼氧——好氧的生化法工艺流程,处理混酸硝化法生产硝基苯产生的硝化废水及硝基苯气相催化还原法生产苯胺产生的苯胺废水。     

黄瓜霜霉病生物测定技术研究

研究了诱发黄瓜霜霉病孢子囊大量产生的条件;明确了黄瓜霜霉病菌可在低温冰冻条件下保存。接种后20℃左右,保持24 h黑暗,相对湿度90%以上,以后光照16 h/d,适宜霜霉病菌的侵染发展。比较6种生测方法,以叶盘蘸药漂浮法的敏感性及稳定性最好。     

入侵植物香丝草化感作用的生物测定

用入侵植物香丝草[Conyza bonariensis(L.)Crong]地上部分的水浸提液对几种作物种子进行发芽试验,通过发芽率、根长以及苗高来研究香丝草的化感作用。结果表明,香丝草的化感作用是存在的,其水浸提液在高浓度下对供试作物种子活力、根长和苗高均有明显的抑制作用,而在低浓度下则对小麦苗高、绿豆和萝卜的根长具有促进生长的作用;香丝草水浸提液含有酚类物质。     

农药毒力测定教学试验设计的改进

针对农药毒力测定中经常出现的错误,对农药毒力测定教学试验设计进行了改进,使学生在试验教学中探索与分析,从而加深了对理论知识的理解,有效避免了农药毒力测定中该类错误的频繁发生。     

甲磺隆的应用技术及对后茬作物的安全性研究

在冬小麦 1～ 2叶期施用甲磺隆 1.8～ 2.5 g/hm2 ,可有效防除北京地区麦田常见阔叶杂草 ,优于当前常用除草剂苯磺隆 15g/hm2 春季施用的除草效果 ,安全性与春季施用苯磺隆 15g/hm2 相当。实验室降解结果表明 ,当甲磺隆初始浓度为 6.25μg/kg以下时 ,经过215d后 ,对后茬玉米安全。研究表明 ,向日葵是甲磺隆理想的生物测定试材 ,对甲磺隆的最低检出浓度达到 0.125μg/kg,其根长抑制率与除草剂浓度有高度的相关性 ,最佳的剂量 -反应模型为 y=a+b lnx     

井冈霉素A对水稻纹枯病菌的毒力和作用机理研究

根据水稻纹枯病菌 Rhizoctonia solani AG- 1IA在含系列浓度井冈霉素 A马铃薯葡萄糖琼脂培养基 (PDA)上的菌丝生长速率 ,计算出药剂的毒力回归方程为:Y=3.2 30 9+0 .872 0 X,r=0 .9910 ,药剂的 EC50 =10 6 .9μg/ m L,EC75=6 34.5 μg/ m L。在含 5 0 0 μg/ m L井冈霉素 A的 PDA上水稻纹枯病菌的菌丝生长抑制率为 74 .1% ,而田间水稻植株上人工接菌的药效试验结果表明 ,5 0 μg/ m L药液喷洒后 7d和 14 d的防效即可分别达到 77.4 %和 76 .7% ,即药剂在 PDA平板上的理论抑制作用仅是田间活体植株上对病菌实际作用效果的 1/ 10。比较室内毒力和田间药效试验的结果可以看出 ,井冈霉素 A具有对病原菌和寄主植物双重作用的特性。研究首次发现 ,在室内培养基上不能有效抑制病菌生长的 1μg/ m L的井冈霉素 A可以在水稻植株未喷药部位产生防御水稻纹枯病的作用 ,且能够持续诱导植物防御反应相关酶——过氧化物酶 (PO)和苯丙氨酸解氨酶 (PAL)的活性增高,表明该药剂可以激发水稻抗性防卫反应的表达。     

苏云金芽孢杆菌菌种保藏

采用砂土管和滤纸片两种保藏方法，对分属３１个亚种的６１株有代表性的苏云金芽孢杆菌经过１－２３年保存后的菌体存活情况，形态特征及对林业主要害虫舞毒蛾幼虫的杀虫活性进行了试验，并对苏云金芽孢杆菌５个亚种的标准菌株和保存不同年限后的１１项生理生化特性及酯酶型进行了测定。     

Compartmentalization response of two clones of hybrid-poplar

A 14-day bioassay indicated the effectiveness of Compartmentalization evident 24 months following wounding of two clones of hybrid-poplar. The boundary pattern adjacent to columns of wound-initiated discoloration indicated that column boundary layer formation was not the sole determinant for the effectiveness of Compartmentalization.     

Soil properties and nitrogen availability in silvopastoral plantings of Acacia melanoxylon in North Island, New Zealand

Acacia melanoxylon, a N₂-fixing timber tree occurring naturally in eastern Australia, is now promoted as a component of silvopastoral systems; but the interaction of the tree with pasture and soils has not been adequately studied. This study investigated the effects of Acacia melanoxylon on soil nitrogen (N) levels, N availability, soil pH, bulk density, organic carbon, C:N ratios and soil moisture in three separate silvopastoral sites with contrasting soil types in the North Island of New Zealand. At each site four tree stocking rates were studied (0, 500, 800, and 1700 stems ha^–1). The trees were nine years old at the time of the study. Soil samples from each study site were taken once at three depths (0 to 75 mm, 75 to 150 mm, and 150 to 300 mm), with three replicates per tree stocking rate. Soil analyses showed that although there were differences between soil types, few statistically significant differences occurred due to tree stocking rate. A greenhouse pot trial growing ryegrass (Lolium multiflorum L. cv. Concord) in soil from the A horizon of each soil type from under the trees and the open pasture found that ryegrass yield, N uptake and N supply increased with increasing tree stocking rate. Increased N supply under the trees, coupled with greater soil moisture compared to the open pasture may have accounted for the higher pasture yield under Acacia melanoxylon compared to non dinitrogen fixing tree species. This study suggested that Acacia melanoxylon in a silvopastoral system had the potential to increase soil N availability.This revised version was published online in November 2005 with corrections to the Cover Date.     

Pb2+对甘肃纹党种子萌发和幼苗生理特性的影响

以甘肃道地中药材纹党(Codonopsis pilosula)为对象，通过室内培养试验，研究不同浓度10^-6、10^-5、10^-4、10^-3 mol/L Pb²⁺处理对纹党种子萌发、幼苗生长以及生理特性的影响，为探究Pb²⁺污染对纹党品质的影响提供依据。结果表明，Pb²⁺对纹党种子吸胀过程中相对吸水量的增加有抑制作用，随着Pb²⁺浓度的提高，党参种子的萌发率、萌发指数、幼苗生长及根尖微核和有丝分裂率变化，表现出先升高后降低的趋势；低浓度的Pb²⁺处理能够促进叶绿素的形成，高浓度则抑制叶绿素形成；可溶性糖、游离脯氨酸和丙二醛含量，随Pb²⁺浓度的升高而增加；Pb²⁺对SOD、POD和CAT活性有较强的抑制作用。可见，生物测定结果大多达到显著差异水平。