植物病害生防制剂的研究进展

从微生物源杀菌剂(农用抗生素和活体微生物杀菌剂)、植物源杀菌剂、半合成杀菌剂、遗传工程杀菌剂等方面综述了植物病害生防制剂的研究和应用进展,展望了植物病害生防制剂的发展前景.     

Dimethylsulfoniopropionate as a foraging cue for reef fishes

Coral reefs resemble islands of productive habitats where fishes aggregate, forage, and spawn. Although it has been suggested that some reef fishes use biogenic chemicals as aggregation cues, specific chemicals have not been identified. Dimethylsulfoniopropionate (DMSP), a secondary metabolite of many marine algal species, is released during foraging by higher-order consumers. DMSP has been studied intensively for its role in oceanic sulfur cycles and global climate regulation, but its ecological importance to marine fishes is unknown. We present evidence that planktivorous reef fishes will aggregate to experimental deployments of DMSP over coral reef habitats in the wild.     

Clathrate hydrates of air in antarctic ice

Measurements of the dissociation pressure of nitrogen hydrate and oxygen hydrate show that the clathrate hydrate of air with the formula (N(2), O(2)) 6H(2)O should exist below about 800 meters in the Antarctic ice sheet. This accounts for the disappearance of gas bubbles at depths greater than 1200 meters. The hydrate should exist from this depth to prise 0.06 percent of the ice.     

Amino acids in an antarctic carbonaceous chondrite

Amino acids have been found in aqueous extracts of a C2 carbonaceous chondrite recovered from Antarctica. The composition of the amino acids strongly suggests that they have a meteoritic origin. Comparison of these results with those obtained with other C2 chondrites supports the view that Antarctic meteorites have not been significantly altered by terrestrial processes since their fall.     

Should arthropod parasitoids and predators be subject to host range testing when used as biological control agents?

Testing of candidate biological control agents to estimate their likely field host ranges in the area of release has been part of weed biological control for several decades, with evolving techniques and goals. Similar efforts have been made less often for parasitoids and predators being introduced for arthropod biological control. Here, we review both techniques of host range testing and social objectives of such screening. We ask whether agents introduced for arthropod biological control should be subjected to host range testing before release, and if so, are methods used for estimating host ranges of herbivorous arthropods appropriate, or are different approaches needed. Current examples in which host range testing has been employed for arthropod biological control are reviewed. We conclude with recommendations concerning guiding principles about use of host range testing. We recommend modest expansion of host range testing for arthropod biological control for projects on continents. We recommend more extensive testing for projects of introduction onto islands. We note that introductions to islands could provide opportunities to gain experience in use of host range estimation for this class of organisms and to conduct post release evaluations of host ranges. We urge caution in efforts to mandate host range testing but simultaneously recommend consultation between biological control workers and insect conservationists.     

Weddellite in a marine gastropod and in antarctic sediments

The calcium oxalate dihydrate mineral, weddellite, has been identified in a microarchitectural component of the gizzard plates from the deepwater gastropod Scaphander cylindrellus. This is the first indication of nonpathologic precipitation of this mineral by an animal species. A new occurrence of weddellite in sediments from the Weddell Sea, Antarctica, is also reported, lending support to the earlier interpretation that the mineral is an authigenic constituent of the sediments in this area.     

Infiltration of a Hawaiian community by introduced biological control agents

To examine the community-wide effects of introduced biocontrol agents on Kauai Island, Hawaii, we constructed quantitative food webs showing interactions among plants, moths, and moth parasitoids in a native forest. Eighty-three percent of parasitoids reared from native moths were biological control agents, 14% were accidental immigrants, and 3% were native species. Although parasitism by biological control agents reached 28% in some species of moth, all biocontrol agents reared had been released before 1945. This study highlights the importance of considering the potential damage caused by an introduced control agent, in addition to that caused by the target alien species.     

烟草生物防治物的引入与风险评价

针对烟草生物防治物的引入,本文提出引入生物防治物的风险评价理论与方法,旨在正确评价引入生物防治作用物的安全性和可利用性,解决理论及实践上面临的新问题,为决策部门提供可靠的依据．风险评价包括风险分析与风险控制,对生物防治作用物的为害性识别、风险识别及风险定量研究则是风险评价的主要内容     

复合保鲜剂对冻藏虾夷扇贝品质的影响

为研究复合保鲜剂对冻藏虾夷扇贝Patinopecten yessoensis品质的影响,以感官评定、挥发性氨基态氮(TVB-N)、细菌总数(TVC)、p H、硬度、弹性、内聚性、耐咀性、SH基和可溶性蛋白质含量为评定指标,进行了由10%氯化钠、3%乙醇、2%甲壳素、5%甘油、3%蔗糖与10%抗冻蛋白AFPs组成的复合保鲜剂对虾夷扇贝冷冻贮藏(-20℃±2℃)过程中品质变化的影响试验。结果表明:复合保鲜剂能有效地抑制TVB-N值的上升速度和硬度、感官评价值的降低速度,但对TVC、p H、弹性、内聚性、耐咀性、SH基总量和可溶性蛋白质几乎无影响。研究表明,经此复合保鲜剂处理后,冻藏虾夷扇贝的品质明显改善,贮藏货架期可得到适当延长。     

Increase of atmospheric methane recorded in antarctic ice core

Air entrapped in bubbles of cold ice has essentially the same composition as that of the atmosphere at the time of bubble formation. Measurements of the methane concentration in air extracted by two different methods from ice samples from Siple Station in western Antarcitica allow the reconstruction of the history of the increase of the atmospheric methane during the past 200 years.     

复合保鲜剂对冻藏虾夷扇贝品质的影响

为研究复合保鲜剂对冻藏虾夷扇贝Patinopecten yessoensis品质的影响,以感官评定、挥发性氨基态氮(TVB-N)、细菌总数(TVC)、p H、硬度、弹性、内聚性、耐咀性、SH基和可溶性蛋白质含量为评定指标,进行了由10%氯化钠、3%乙醇、2%甲壳素、5%甘油、3%蔗糖与10%抗冻蛋白AFPs组成的复合保鲜剂对虾夷扇贝冷冻贮藏(-20℃±2℃)过程中品质变化的影响试验。结果表明:复合保鲜剂能有效地抑制TVB-N值的上升速度和硬度、感官评价值的降低速度,但对TVC、p H、弹性、内聚性、耐咀性、SH基总量和可溶性蛋白质几乎无影响。研究表明,经此复合保鲜剂处理后,冻藏虾夷扇贝的品质明显改善,贮藏货架期可得到适当延长。     

Multiple hemoglobins in fishes

Paper electrophoregrams of the hemoglobins from 14 species of fresh- and salt-water fish demonstrated from one to three components. The relative distribution of these fractions was determined for all species. Mobilities of the three hemoglobins of rainbow trout were calculated from moving-boundary patterns. Low anodal mobility at pH 8.8 was characteristic of many species examined.     

秸秆常温快速腐熟生物菌剂的筛选

在常温条件下使用由不同菌系组成的生物菌剂对秸秆进行分解试验。平板试验和电镜试验观察表明,生物菌剂具有加速秸秆分解的能力。田间试验结果表明,7号腐解剂分解秸秆后的残留率、剪切力最低。说明其分解效果最好,由此筛选出最佳解菌系组合配方。     

几种生物药剂防治菜青虫的药效试验

菜青虫是黑龙江省柳河地区蔬菜最重要的害虫之一,近年来发生呈上升趋势,经常暴发成灾。文章用威克达乳油、农家乐乳油、菜地隆乳油及绿维特水剂等4种无公害药剂在田间对菜青虫幼虫进行了防治试验。结果表明,1%威克达乳油2 000倍液施药1 d后防治效果76.13%,施药后3 d防治效果80.91%,施药后7 d防治效果86.34%。经多重比较分析结果表明,在防治后1、3、7 d,1%威克达防治效果与其他3种药剂比较均有显著差异,具有防治效果好、成本低、无污染等特点,在生产中可以应用。     

Reduced antarctic ozone depletions in a model with hydrocarbon injections

Motivated by increased losses of Antarctic stratospheric ozone and by improved understanding of the mechanism, a concept is suggested for action to arrest this ozone loss: injecting the alkanes ethane or propane (E or P) into the Antarctic stratosphere. A numerical model of chemical processes was used to explore the concept. The model results suggest that annual injections of about 50,000 tons of E or P could suppress ozone loss, but there are some scenarios where smaller E or P injections could increase ozone depletion. Further, key uncertainties must be resolved, induding initial concentrations of nitrogen-oxide species in austral spring, and several poorly defined physical and chemical processes must be quantifed. There would also be major difficulties in delivering and distributing the needed alkanes.     

Freezing resistance in polar fishes

Arctic and antarctic fishes, living in contact with sea ice at -1.9 degrees C, have plasma equilibrium freezing points near -1.2 degrees C which are dependent on salt concentrations. These supercooled fishes have plasma protein concentrations much higher than other polar animals have, and the proteins impede ice propagation at temperatures down to -2 degrees C. Plasma protein concentration increases as environmental water temperature decreases.     

鱼类的变态发育及其适应意义

综述了不同纲目一些代表鱼类的变态发育现象,变态发育对环境的适应,以及鱼类变态发育的特点,并对变态发育研究中存在的问题进行了讨论。