施肥措施对重金属污染土壤-植物系统影响的研究进展

植物修复作为一种原位修复方法,因其投入成本低、拥有良好的经济效益和生态协调性等优点而成为国内外研究热点,在重金属污染农田实地得到广泛应用。本文综述施肥农艺措施强化重金属污染土壤植物修复以及对土壤-植物系统影响的研究进展,如土壤重金属含量和生物有效性的影响等,以便进一步提高植物修复效率,为今后规模化修复重金属污染农田土壤提供参考。     

人参锈腐病菌毁灭柱孢菌酶促降解人参皂苷研究

皂苷被认为是植物抵抗病原真菌侵袭的防御物质,具有抗真菌活性.许多成功侵染植物的真菌通过产生皂苷解毒酶水解皂苷糖链上的糖残基,解除皂苷的毒性.本文研究了人参锈腐病菌毁灭柱孢菌Cylindrocarpon destructans和非人参病原菌构巢曲霉菌Aspergillus nidulans降解人参皂苷的能力.结果显示,毁灭柱孢菌能够产生胞外糖苷酶,水解二醇型人参皂苷Rb1、Rb2、Rc和Rd的C-3位和C-20位末端单糖,产生四种主要产物：绞股蓝皂苷XVII（G-XVII）、C-O、Mb和人参皂苷F2,而构巢曲霉菌只能将人参皂苷Rb1降解为Rd,不能降解其它的人参皂苷.这些结果说明,人参皂苷降解酶在毁灭柱孢菌的致病过程中可能发挥了重要作用.     

Dynamic superposition and simulation research on flowing of gas outburst and mine ventilation network

In allusion to the “5·30”especially serious coal and gas outburst accident of Tonghua coal mine of Songzao Coal Electricity Group CO., LTD in 2009, a detailed simulation of the mutation process of mine ventilation system during gas outburst disaster period is done by using theory of ventilation network with sources and numerical simulation technology (we develop a computer simulation system). Three changing processes, namely outburst overflow, natural flow and ventilation downstream occurs in the ventilation system after outburst. Due to the expanded power of outburst source, gas enters main ventilation roadways at first, and flows outward, and flows counter-current along main intake air roadway, and then enters low air quantity roadways with air doors or underground chamber, which leads to gas concentration overrun and threat to the whole mine. After outburst, gas power disappears. Due to the action of gas natural ventilation pressure, mine ventilation may begin to flow naturally. After the ventilation systems are restored, gas flows with the wind as a result of the power of the main fan. Due to the interference of gas natural ventilation pressure, the operating points of main fans may drift (relative to roadway structure), but the operating points recover with the discharge of gas. It is worth noting that the detention time of gas in low air quantity roadways and underground chambers is relatively long, and the gas becomes continuous gas supply sources, so it is dangerous. In addition, the delayed pour between main roadways and by-pass low air quantity roadways and the gas natural ventilation pressure caused by gas detention may lead to airflow disorder of reversion in some local circuits, and may enlarge the affected range of gas, or lead to the delay and detention of gas discharge.     

镉对龙葵种子萌发及子叶抗氧化酶活性的影响

龙葵(Solanum nigrumL.)是Cd超累积植物,可用于植物冶金和Cd污染土壤的植物修复。超累积植物的生理基础研究有助于提高其对Cd的富集效率。龙葵种子在含有不同浓度CdCl(20、30、50、100、150、200μmol·L-1和300μmol·L-1)的琼脂培养基上萌发7d。结果表明,龙葵在200μmol·L-1和300μmol·L-1Cd时发芽率显著降低,而低浓度Cd(30～150μmol·L-1)胁迫下无显著差异;在Cd≥30μmol·L-1时,活力指数、发芽势均显著降低,幼苗的生长受到显著抑制。幼苗生长分析表明:在30～150μmol·L-1Cd处理下根长下降约17%～35%,显著低于200～300μmol·L-1Cd处理(下降79%～90%);株高随Cd浓度的升高逐渐下降。子叶抗氧化酶活性分析表明:100～150μmol·L-1Cd胁迫下,CAT和APX活性显著上升;在Cd胁迫下,SOD活性降低但维持在较高的活性水平。表明龙葵幼苗能忍耐小于150μmol·L-1Cd,抗氧化酶活性在抵抗Cd毒害方面发挥重要作用。     

棉蚜对吡虫啉等杀虫剂抗药性品系的室内选育及抗药性风险评价

通过室内杀虫剂处理水培棉苗选育抗性棉蚜,研究棉蚜在药剂诱导下抗性的变化,比较吡虫啉、吡虫啉 增效磷、氧乐果和氰戊菊酯对棉蚜抗性诱导的差异,评价棉蚜对吡虫啉抗药性的风险.结果表明,用吡虫啉等药剂分别选育棉蚜至18代都能够诱导抗性上升,棉蚜对吡虫啉抗性达到10.08倍,对吡虫啉 增效磷的抗性达9.70倍;而用氧乐果和氰戊菊酯分别选育棉蚜至12代时,其抗性分别达28.48倍和35158倍.各抗性品系停止选育12代,抗性下降.     

Impacts of orchard pesticides on Galendromus occidentalis: Lethal and sublethal effects

Fifteen pesticides were tested in laboratory bioassays on Galendromus occidentalis (Nesbitt), the principal phytoseiid mite predator in Washington apple orchards. We developed a rating system for pesticides using lethal and sublethal effects, and applied the rating system to our results. At the 1× dose, only spinetoram and lambda-cyhalothrin caused >75% acute mortality of females. Carbaryl, azinphos methyl, spinosad, spirotetramat, cyantraniliprole, and sulfur had relatively little effect on mortality, but moderate to high effects on fecundity. Egg viability was most affected by carbaryl, spinosad, novaluron, spirotetramat, and sulfur. Lambda-cyhalothrin, spinosad, and sulfur were the most toxic compounds to larvae. Materials such as sulfur and spinetoram had widely divergent toxicity to adults versus larvae. The cumulative impact of these effects was best integrated by the numbers of live larvae of the F₁ generation. Using this measurement, spirotetramat, sulfur, spinetoram, acetamiprid, lambda-cyhalothrin, carbaryl and novaluron caused the greatest percentage reduction compared to the check, yet only spinetoram and lambda-cyhalothrin would have been identified as harmful in acute bioassays. These bioassays provide support for the benefits of measuring a range of sublethal effects and testing multiple life stages to provide an accurate assessment of the harmfulness of reduced-risk pesticides.     

基于神经网络的食用菌价格预测模型的建立

为解决食用菌市场价格预测的问题,基于模糊神经网络建立食用菌价格预测模型,对5种常见的食用菌栽培方案进行了价格预测,可以客观准确地预测未来食用菌价格走势,减少价格波动带来的经济影响。     

旱稻×稗草杂交后代YF2-1光合作用气体交换、叶绿素荧光和抗氧化酶系统对渗透胁迫的响应

为了明确旱稻×稗草杂交后代YF2-1对渗透胁迫的耐性是否得到了改善，以YF2-1及其母本旱稻品种H65为材料，在苗期采用PEG-6000进行渗透胁迫处理，研究它们的气体交换参数、叶绿素荧光参数及抗氧化酶活性对渗透胁迫的响应。结果表明，在渗透胁迫处理下，YF2-1更能维持较高的净光合速率(P_n)和气孔导度(G_s)。这可能与YF2-1具有更好的持水能力，并能有效地通过热耗散(NPQ高)消耗过剩光能，通过高活性的抗氧化酶诱导来清除活性氧，从而避免活性氧伤害相关。的确，旱稻与稗草的远源杂交提高了旱稻对渗透胁迫的抗性。     

桂林猫儿山苏云金芽孢杆菌的筛选及抑菌性研究

[目的]探明桂林市猫儿山风景区Bt的多样性和分布概况.[方法]在该景区海拔1 800 ～2 000 m的常绿针阔叶林和海拔2 000m以上的灌丛矮林采集土壤样品共1 168份,分离Bt菌株,并对Bt分离株进行伴孢晶体蛋白分子量的测定和发酵上清液抑菌性分析.[结果]从该景区针阔叶林和灌丛矮林的146个样点共筛选出44个Bt菌株,出菌率达30.14％;其中14株Bt菌株均表达120 kD的蛋白,12株表达66 kD的蛋白.将14株Bt分离株的发酵液上清进行抑菌检测,仅有4株对草生欧文氏杆菌有抑制效果,其中9号的Bt分离株抑制率最高.9号Bt分离株发酵液上清的抑菌物质热稳定性研究结果表明抑菌物质在65℃下2h内不失活,其至少含有2种抑菌物质.[结论]为丰富我国西部地区Bt资源的开发利用奠定了基础.     

城乡统筹发展战略与新农村建设研究

城乡均衡发展直接关系着社会稳定和国民经济的健康发展,为了促进统筹城乡均衡发展,解决三农问题,缩小城乡差距,实现城乡经济、社会、文化持续协调发展,最终实现共同富裕,通过对统筹城乡发展含义的概述,深入分析城乡间差距,并提出实现统筹城乡发展的战略意义,重点探讨了统筹城乡发展的方法与措施,以此促进城乡协调均衡发展。