房屋建筑材用防腐剂的毒性试验

通过对十八种药剂配方(其中水溶性配方15种、油溶性配方3种)对木腐菌的毒性试验及对初筛后的配方进行流失后毒性试验,结果表明,水溶性配方中的铜铬砷即CCA_3、CCA_4、CCA_5,铜铬硼即CCB_5配方,以及油溶性配方中的P—B剂的毒性较大。     

Growth and nutritional responses of bareroot Jeffrey pine on a Sierra Nevada surface mine to minisite applications of fertilizer and lime

The effects of two controlled release fertilizers, Forestcote 22-4-6 + Minors and Dry Site 21-6-2 + Minors, and also dolomitic lime, on growth and nutrition of bareroot Jeffrey pine (Pinus jeffreyi Grev. & Balf.) were investigated. Forestcote, which consists of loose prills, and Dry Site, consisting of prepackaged prills, were administered with two rates, while a single liming rate was used. An acidic Sierra Nevada surface mine provided the study site, and all amendments were applied at outplanting to the backfill of augered planting holes. Without impacting survival, both fertilizer formulations enhanced seedling growth, particularly at a 16 g rather than an 8 g application rate, although Forestcote was marginally more effective in this regard. In contrast, liming at a 27 g rate induced severe mortality and offset much of the growth gains resulting from fertilization. Improvements in N and P nutrition, as revealed by foliar analysis, probably accounted for much of the growth stimulation exhibited by fertilized seedlings, but reductions in the uptake of potentially phytotoxic trace elements such as Mn and Al and increases in base cation/metallic element ratios likely also contributed. The high application rate was generally preeminent in eliciting these nutritional responses. Liming induced little alteration of seedling nutrition. Impaired water relations may have caused the unfavorable responses to this treatment.     

Antinociceptive effect and acute toxicity of the Hyptis suaveolens leaves aqueous extract on mice

The aqueous extract of Hyptis suaveolens leaves was studied for their antinociceptive property in chemical and thermal models of nociception in mice. Oral administration of the aqueous extract (100, 200, and 400 mg/kg) dose-dependently reduced the number of writhings induced by acetic acid, decreased the licking activity of the early phase in formalin test and increased the reaction time in hot-plate test. The antinociceptive effect was significantly antagonized by naloxone (3 mg/kg; i.p.). Preliminary acute toxicity study showed that no animal death with doses up to 5 g/kg (p.o.).     

Fertilizer-induced Changes in Rhizosphere Electrical Conductivity: Relation to Forest Tree Seedling Root System Growth and Function

Fertilization is standard practice in forest tree seedling nursery culture. Additionally, fertilization at outplanting has potential to facilitate nutrient uptake and reduce transplant shock. Fertilization, however, may dramatically alter rhizosphere chemical properties such as pH, ion availability, and electrical conductivity (EC). These changes may inhibit root system growth and function by reducing soil osmotic potential and creating specific ion toxicities. The risk of root damage associated with high EC levels appears to be dependent on species, age of root system, and soil moisture availability. Root inhibition in container nursery culture of conifers is likely to occur above 2.5 dS m⁻¹, though threshold EC levels for bareroot culture and field plantings are largely unavailable. Fertilization at outplanting has the added risk that drought conditions may prevent leaching of excess fertilizer salts, which can increase rhizosphere EC beyond safe levels and ultimately impair root uptake of water or nutrients. For fertilization programs to be successful, a critical threshold balance must be maintained between optimizing seedling nutrient availability in the rhizosphere, while minimizing potential for root damage. Future research is needed to identify optimal EC levels for a range of species across all stages of the reforestation process, from nursery culture through plantation establishment.     

白僵菌优良菌株的选育

本研究将所收集的28个菌株,用稀释单孢分离的方法,进行生长特征、生长速度、产孢量和室内外对松毛虫致病力的测定比较,以闽林2、闽林1、闽林3号菌株表现突出,为优良菌株。     

低温条件下溴甲烷和硫酰氟对紫穗槐豆象的毒力

熏蒸环境温度为5℃、10℃的条件下,设计6～10个不同剂量分别开展溴甲烷和硫酰氟熏蒸杀灭紫穗槐种子携带紫穗槐豆象(Acanthoscelides pallidipennis)老熟幼虫的毒力试验,应用PoloPlus软件进行机率值分析的结果表明:在5℃条件下,预计紫穗槐豆象老熟幼虫达到99.9968%死亡率所要求的CT值(Lct_(99.9968))为溴甲烷2855.7g.h/m~3、硫酰氟3973.5g.h/m~3,熏蒸24h所需剂量为119.3g/m~3、158.7g/m~3;在10℃条件下,Lct_(99.9968)为溴甲烷2145.2g.h/m~3、硫酰氟1436.3g.h/m~3,熏蒸24h所需剂量为88.1g/m~3、59.0g/m~3。因此,随着熏蒸温度的提高,硫酰氟对紫穗槐豆象老熟幼虫的毒力作用增长明显,可作为进出口紫穗槐种子检疫处理的有效熏蒸剂,但熏蒸的环境温度须高于10℃。     

不同的球孢白僵菌对草地螟的毒力测定

用16个分离自内蒙古地区的球孢白僵菌(Beauveria bassiana)菌株对草地螟(Loxostege sticticalis L.)幼虫的致病力作了室内测定.结果表明,16个菌株对草地螟幼虫均表现出一定的致病率,但毒力强弱有所不同.通过对16个菌株进行毒力测定,筛选出1个毒力相对较强,有效死亡率(僵虫率)仍较高的菌株S3.同一个菌株处理下,草地螟幼虫的累积死亡率随孢子浓度增加而上升,接种后的幼虫死亡数逐日减少.说明累积死亡率是随着处理后时间的延长而递升;菌株的半死亡时间(LT50)随浓度的增加而减小.     

Effects of diazinon on biochemical parameters of blood in rainbow trout (Oncorhynchus mykiss)

Existence of diazinon, an organophosphorous pesticide, in river waters of Iran near rice paddy fields has been reported by some authors. The present research aimed to determine the acute toxicity and evaluate the effect of sub-lethal concentrations of diazinon on some biochemical parameters of rainbow trout, Oncorhynchus mykiss after 7, 14 and 28 days. No significant differences were observed in the plasma levels of creatinine among the treatment groups at different sampling intervals. Acetylcholinesterase activity and the levels of total protein, albumin as well as globulin in plasma were significantly reduced at both concentrations tested (p < 0.05). Lactate dehydrogenase activity was only decreased on 7th day in 0.1 mg/L diazinon treatment (p < 0.05). Creatine kinase activity was significantly lower in 0.1 mg/L diazinon group at 14th and 28th sampling periods, whereas its activity significantly increased in fishes exposed to 0.2 mf/L diazinon only on 7th day (p < 0.05). Aspartate aminotransferase, alanine aminotransferase activities and glucose levels in diazinon treated groups were significantly higher than the controlled group at experimental periods (p < 0.05). In conclusion, long-term exposure to diazinon at sub-lethal concentrations induced biochemical alterations in rainbow trout, and offers a simply tool to evaluate toxicity-derived alterations.     

甲氰菊酯对斑马鱼的毒性效应

选用模式生物斑马鱼(Brachydanio rerio)作为毒性实验动物,探索甲氰菊酯(fenpropathrin)对鱼类的毒性效应,为农业生产和环境保护提供参考数据。结果显示甲氰菊酯对斑马鱼成鱼96h LC50为3.38×10-3mg/kg,属于剧毒级,安全浓度为0.34×10-3mg/kg;较低浓度下甲氰菊酯对斑马鱼早期发育影响不显著,在较高浓度1、10mg/kg下,斑马鱼96h畸形率分别达到84%和90%,心包囊肿率分别为25%和88%,而致死效应不明显。亚致死剂量下甲氰菊酯对斑马鱼肝胰脏GPT、GOT、SOD活性有明显诱导效应,在高浓度和长时间暴露下诱导效应降低;肝胰脏中AChE活性显著地受到甲氰菊酯的抑制,抑制效应对毒物的浓度和染毒时间有良好的依赖性,是一种良好的环境污染检测生物学指标。     

河朔荛花灌丛特性及其毒性的初步研究

对山西吉县蔡家川流域荛花灌丛的分布及其提取液的毒性进行了初步研究，结果表明，河朔荛花一般分布在阳坡立地上，半阳坡生长不良，阴坡基本无分布，其生物量与立地条件有明显的关系，其乙醇取液对3龄粘虫有一定的拒食作用，胃毒作用不明显，无触杀作用，对粘虫的生长具有明显的抑制作用。