异型莎草和鸭舌草种子萌发条件研究

研究了0．1％升汞溶液、不同浓度赤霉素、不同浓度乙烯利在不同浸种时间、不同的培养基质中对异型莎草和鸭舌草种子发芽率的影响。试验结果证明，异型莎草以1／2MS 10mg/kg GA3的固体培养基，50mg/kg乙烯利浸种12h发芽率最高，达96．38％；鸭舌草以Harvais 0．1mg／kg乙烯利的固体培养基，50mg/kgGA3浸种12h发芽率最高，达89．6％。     

化学方法解除野慈姑种子休眠研究

HCl、NaOH、Na2CO3、NaCl、赤霉素（GA3）、芸薹素内酯（BR）浸种处理,探讨溶液浓度、浸种时间对野慈姑（Sagittaria trifolia Linn．）种子萌发的影响。结果表明,NaOH溶液浸种处理可以作为快速解除野慈姑种子休眠、提高发芽率的方法,最佳处理为25％NaOH溶液浸种4h,可使野慈姑种子萌发率达73．00％。HCl溶液浸种处理仅能解除部分野慈姑种子的休眠,20％HCl溶液浸种4h野慈姑种子的发芽率最高;为48．33％。Na2CO3、NaCl、GA3、BR溶液浸种处理,野慈姑种子的最高发芽率分别仅为10．33％、9．33％、11．33％、9．67％,不能用于解除野慈姑种子的休眠。     

叶甜菜种子发芽特性的研究

研究了不同化学药剂和植物激素浸种处理及种球色泽、粒径、储藏时间等对叶甜菜种子发芽的影响。研究表明,用一定浓度的双氧水、硼酸、磷酸二氢钾浸种处理叶甜菜种子,可提高种子发芽率、发芽势与发芽指数,其中以10g/kgH2O2、0.5g/kgH3BO3和5g/kgKH2PO4处理效果最好。赤霉素处理(10、30、50、70、100mg/L)叶甜菜种子,促进种子发芽的效果不明显。吸湿-回干处理对叶甜菜种子发芽有良好的促进作用。叶甜菜种球色泽、粒径大小与发芽的关系密切,黄色或黄褐色的种球比黑色或褐色种球及大、中粒种子比小粒种子发芽力显著;叶甜菜种子不耐贮藏,发芽力下降较快,使用年限仅为1a。     

阿维菌素和三唑磷对泥鳅的急性毒性研究

阿维菌素、三唑磷LC50分别为对泥鳅的24-96h致死中浓度,0．031-0．064mg／L、3．771-5．434mg／L,对泥鳅的急性毒性分别为高毒和中毒。2者按浓度1：1混配后24h,对泥鳅毒性具有协同增效作用,48、72、96h具有毒性相加作用。     

天然油菜素内酯对五种牧草种子发芽和胚根下胚轴伸长的影响

用9个不同浓度的天然油菜素内酯溶液浸种处理5种牧草种子,观测其对种子发芽和胚根下胚轴伸长的影响。结果表明,0.01 mg/L浓度处理使苜蓿种子发芽率比对照提高了32.2%,发芽天数缩短了1.4 d;0.01mg/L处理使鲁梅克斯种子发芽率增加了27.8%,0.05 mg/L处理使其发芽天数提前了0.8 d;0.03 mg/L处理使普那菊苣种子发芽率提高了28.9%,发芽天数缩短了0.3 d;0.4 mg/L处理使串叶松香草种子发芽率增加了26.7%,发芽天数提前了1.2 d;0.03 mg/L处理使小冠花种子发芽率提高了23.3%,0.05 mg/L使其发芽天数缩短了0.9 d。0.05、0.07、0.03、0.4和0.03 mg/L处理对苜蓿、鲁梅克斯、普那菊苣、串叶松香草和小冠花胚根下胚轴伸长的促进效应最为明显。     

聚乙二醇胁迫下赤霉素浸种对番茄种子萌发和幼苗生长的影响

以番茄幼苗为材料,研究了50 mg/g 的赤霉素(GA3)和清水浸种后用不同浓度的聚乙二醇(0、40、80、120 mg/g)胁迫对番茄种子萌发及幼苗生长的影响.结果表明:40 mg/g的聚乙二醇胁迫对番茄种子的萌发率、发芽指数、幼苗株高、根长有促进作用,120 mg/g的聚乙二醇明显抑制种子的萌发率、发芽指数、幼苗株高、根长;不同浓度的聚乙二醇胁迫明显降低了幼苗的叶绿素含量.用50 mg/g GA3浸种后明显增加聚乙二醇胁迫下番茄种子的萌发率、发芽指数、幼苗株高、根长和叶绿素含量.用50 m g/g GA3浸种对番茄幼苗的生长有一定的促进作用.     

莰酮对柑桔天牛的生物活性

在室内测定了樟树(Cinnamomum camphora L.)天然产物莰酮-[2](Cam-phor C10H16O)的杀虫活性和作用方式，并进行了田间试验。结果表明，莰酮对天牛成虫有较强的驱避、熏蒸和触杀作用。每点投放2％莰酮DP1-2g，药后24h对天牛驱避效果为55．00％-85．00％，药后72h达到94．12％-100．00％；熏蒸致死中浓度为8．20mg/L，触杀致死中浓度为15．25mg／L。经回归和相关分析，处理浓度与作用效果相关性均达到极显著水平。每洞穴喷2％莰酮DP0．1-0．2g，对天牛幼虫防治效果达85．80％-100％；每袋装2％莰酮DP1．5-2．5g，药后7-15天对天牛成虫驱避效果为80．95％-100％。药后30-60天为68．29％-86．36％，田间防治效果显著。     

蒲公英水提液对几种植物的化感作用

采用培养皿滤纸法,以反枝苋（Amaranthus retroflexus L．）、番茄（Lycopersicon esculentum Miller．）、生菜（Lactuca sativa L．var．ramosa Hort）、小白菜（Brassica rapa L．Chinensis Group）和小麦（Triticum aestivum L．）5种植物为受试植物,对蒲公英（Taraxacum mongolicum）水提液的化感作用进行了测定。结果表明,蒲公英水提液对5种植物种子的萌发均有一定的抑制作用。当浓度为0．1g／ml时,对5种植物种子萌发的抑制率均为100％,随着浓度降低,对种子萌发的抑制率减小。当浓度为0．1、0．05、0．025g／ml时,对5种植物根的生长、茎的生长均有一定抑制作用。当浓度为0．0125g／ml时,对反枝苋、番茄和生菜的幼苗茎生长有抑制作用,而对小白菜和小麦幼苗茎生长有促进作用。     

反枝苋种子休眠解除方法研究

研究了光照和黑暗两种条件下氢氧化钠（NaoH）、盐酸（HC l）、赤霉素（GA3）和乙烯利（ETH）处理对反枝苋种子萌发的影响。结果表明,氢氧化钠、盐酸、赤霉素和乙烯利浸泡处理均可以明显提高反枝苋种子的发芽率,且随着试剂浓度的提高,发芽率表现出单峰变化曲线,浓度过低或过高均不利于种子的萌发。其中,赤霉素对解除反枝苋种子休眠最有效,且以200 mg/L浸泡处理24 h效果最好,发芽率可达90.8%,比对照提高了52.5百分点。其次为4%NaOH和6%HC l处理1 h,与800 mg/L ETH处理24 h的效果相当,发芽率在70%~75%之间。黑暗条件不利于反枝苋种子的萌发,发芽率略低于光照条件。     

杀虫单在水稻和稻田土壤、水中的残留分析方法研究

本文通过对水稻和土壤样品用HCl水溶液提取,NaOH溶液调节pH,经石油醚萃取,正己烷定容,气相色谱（GC—ECD）测定水稻和土壤中杀虫单残留,杀虫单的最小检测量为1．0×10^-11g,在稻田土壤、水稻植株、谷壳和糙米中的最低检出浓度为2．5×10^-3mg／kg．在稻田水中的最低检出浓度为5．0×10^-4mg／kg。当添加浓度0．05～5．0mg／kg时,杀虫单在水稻植株、稻田水、糙米、谷壳和稻田土壤中的添加回收率分别为90．2％～99．3％、94．2％～98．7％、92．6％-99．1％、92．7％-99．1％、90．8％～101．2％;变异系数分别为2．2％～11．4％、1．5％-2．2％、43％～6．5％、1．3％～4．9％、2．1％～10．7％。     

Spatial regression approach to estimate synthetic unit hydrograph by geomorphic characteristics of watersheds in arid regions

Rainfall-runoff relationship in arid regions is unique and challenging to study. Studies for bridging the hydro-meteorological knowledge gap for planning, designing and managing water resources is therefore vitally important. The objective of this study is to develop a method for estimating unit hydrograph at reasonably finer time resolutions (10-min and 1-h) which can be easily adaptable by practitioners at sub-catchment levels, especially when the focus area is ungauged. Observed wadi-flow at 5-min interval and tipping bucket rainfall measurements at 1-min interval were obtained to cover 10 major watersheds in Oman. The deconvolution method was applied to derive the unit hydrographs (UHs) from wadi-flow and excess rainfall. Key catchment characteristics such as the watershed area, length of the main wadi and the length to the centroid of the catchment area were derived from digital elevation model (DEM) data. The whole study area was then divided into 515 sub-catchments with various shapes and sizes. A strong relationship was found between the wadi length and the length to the centroid of the catchment area (R²>0.89). This relationship was then adopted to simplify the classical Snyder method to determine UHs. Moreover, several parameters of the Snyder method were calibrated to the arid environment by matching the peak-flow, lag-time and three time-widths (75%, 50% and 30% of the peak-flow) of 10-min and 1-h UHs with physical characteristics of the watersheds. All developed relationships were validated with independent rainfall and wadi-flow events. Results indicate that the calibrated parameters in these arid watersheds are quite distinct from those suggested for other regions of the world. A marked difference was found between the 10-min UHs estimated by the S-hydrograph method and the deconvolution method. Therefore, it is concluded that a method depends on natural hydro-meteorological conditions would be more practical in arid region. The proposed methodology can be used for water resources management in arid regions having similar climate and geographical settings.     

农田鼠类数量统计方法的研究

目前统计大仓鼠Cricetulus triton、黑线仓鼠C.barabensis和黑线姬鼠Apodemus agrarius等地面活动的农田鼠类广泛采用夹捕法和查洞法,夹捕法又要求连续布夹三夜。本文对用一夜、连续二夜和三夜夹捕的统计结果作了对比研究,结果表明,三种夹捕方法的统计结果一致,呈极显著正相关。作者认为只用一夜捕鼠减少了工作量和样方去除效应,可在农田鼠情常规测报中代替连续三夜捕鼠法。查洞法的统计结果不能反映农田鼠类数量的季节变化,不宜在鼠情测报中使用。     

Detection of beet yellows virus in sugarbeet plants by enzyme-linked immunosorbent assay (ELISA)

Beet yellows virus can be detected in leaf extracts of infected sugarbeet plants by ELISA. The use of discs was studied and proved to be a valuable and qualitatively reliable method. Leaf material could be stored at 4^o or 22°C for at least six days without affecting the detection of this virus by ELISA. A dramatic decrease in ELISA values was found when leaf extracts were frozen.In an analysis of the distribution of virus over the plant it was found that young leaves present at the moment of infection and those which had still to develop after infection will contain virus. Symptoms produced by systemic virus invasion occur on the oldest leaves containing virus.Samenvatting Het bietevergelingsvirus kan op betrouwbare wijze met de ELISA methode in geïnfecteerde bieteplanten worden aangetoond. Een aanzienlijke vereenvoudiging van de procedure kan worden bereikt met de zogenaamde disc-method, waarbij intacte ponsstukjes in de putjes van de ELISA-plaat worden geïncubeerd. Hierbij komt voldoende virus uit de ponsstukjes voor ELISA vrij. Bladmateriaal kon op verschillende wijzen bewaard worden zonder dat de mogelijkheid om het virus aan te tonen achteruitging. Met bladextracten die ingevroren waren, werden echter slechte resultaten verkregen.In een analyse naar de verdeling van het virus over het loof bleek het virus voor te komen in de geïnoculeerde bladeren, in die bladeren die op het tijdstip van inoculatie minder dan de helft van hun uiteindelijke lengte bereikt hadden en in de bladeren die nog moesten verschijnen. De symptomen ontwikkelden zich op de oudste systemisch geïnfecteerde bladeren.     

浅淡单点校正法和标准曲线法及其在农药分析中的应用

本文从单点校正法和标准曲线法的适用前提条件出发，运用数学方法，探讨了单点校正法代替标准曲线法的条件，并为在农药分析中选择单点校正法和标准曲线法提供依据，从而简化正常农药分析步骤，避免一些分析误差。     

吐伦球坚蚧在杏树上的分布及抽样方法研究

为确定吐伦球坚蚧在杏树上的分布格局及其田间虫口数量估计的最佳抽样方法,以最近邻体法分别对吐伦球坚蚧越冬若虫、成虫和越夏若虫在杏树上的分布进行研究,并比较五点法、棋盘式、双对角线、Z字形、平行线5种抽样方法与总体平均数的差异显著性及各抽样方法的误差率。结果表明：吐伦球坚蚧越冬若虫、成虫和越夏若虫在杏树上的分布均为聚集型。Z字形抽样方法对田间吐伦球坚蚧越冬若虫和成虫进行抽样最可靠;越夏若虫以平行线抽样法最具代表性且最为可靠。     

Dynamics of ecosystem carbon stocks during vegetation restoration on the Loess Plateau of China

In the last few decades, the Loess Plateau had experienced an extensive vegetation restoration to reduce soil erosion and to improve the degraded ecosystems. However, the dynamics of ecosystem carbon stocks with vegetation restoration in this region are poorly understood. This study examined the changes of carbon stocks in mineral soil(0–100 cm), plant biomass and the ecosystem(plant and soil) following vegetation restoration with different models and ages. Our results indicated that cultivated land returned to native vegetation(natural restoration) or artificial forest increased ecosystem carbon sequestration. Tree plantation sequestered more carbon than natural vegetation succession over decades scale due to the rapid increase in biomass carbon pool. Restoration ages had different effects on the dynamics of biomass and soil carbon stocks. Biomass carbon stocks increased with vegetation restoration age, while the dynamics of soil carbon stocks were affected by sampling depth. Ecosystem carbon stocks consistently increased after tree plantation regardless of the soil depth; but an initial decrease and then increase trend was observed in natural restoration chronosequences with the soil sampling depth of 0–100 cm. Moreover, there was a time lag of about 15–30 years between biomass production and soil carbon sequestration in 0–100 cm, which indicated a long-term effect of vegetation restoration on deeper soil carbon sequestration.     

10%溴虫氟苯双酰胺SC对草地贪夜蛾的控制效果

为探索新型杀虫剂溴虫氟苯双酰胺对草地贪夜蛾的防治效果,采用喷雾法和浸叶法在室内研究了10%溴虫氟苯双酰胺悬浮剂(SC)对草地贪夜蛾的杀虫性,并用喷雾法进行了田间控制效果研究。室内试验结果表明,10%溴虫氟苯双酰胺SC喷雾处理对草地贪夜蛾卵的孵化率无明显影响,但能显著提高初孵幼虫的死亡率(P<0.05),各处理校正死亡率均高于78.26%。同时,10%溴虫氟苯双酰胺SC对3龄和5龄幼虫均有较强的活性,处理72 h后的校正死亡率均高于90%,并且随着浓度的增加,死亡率升高。田间药效试验表明,不同浓度的10%溴虫氟苯双酰胺SC处理后1 d和7 d防效均可达96.33%以上,显著高于对照药剂5.7%甲维盐微乳剂(ME)和200 g/L氯虫苯甲酰胺SC;药后14 d各处理防效为41.71%～66.32%,其中10 mL/667m~2处理与对照药剂5.7%甲维盐ME防效相当。研究表明,10%溴虫氟苯双酰胺SC可以有效控制草地贪夜蛾,且速效性和持效性较好,建议每667 m~2使用制剂10～15 mL,防治适期为草地贪夜蛾卵孵化盛期及低龄幼虫期。     

药剂对小麦叶锈菌生物活性试验方法的研究

应用人工接菌方法,小麦叶锈菌能在含有６－苄基氨基嘌呤洋菜培养基中的感病离体小麦叶段上产生夏孢子堆。它在药剂生物活性测定中反应较为灵敏,与室内活体生物测定有较高的相关性,但也存在一定差异。如果两者结合使用,则可取长补短,避免漏筛。     

A general multi-objective programming model for minimum ecological flow or water level of inland water bodies

Assessment of ecological flow or water level for water bodies is important for the protection of degraded or degrading ecosystems caused by water shortage in arid regions, and it has become a key issue in water resources planning. In the past several decades, many methods have been proposed to assess ecological flow for rivers and ecological water level for lakes or wetlands. To balance water uses by human and ecosystems, we proposed a general multi-objective programming model to determine minimum ecological flow or water level for inland water bodies, where two objectives are water index for human and habitat index for ecosystems, respectively. Using the weighted sum method for multi-objective optimization, minimum ecological flow or water level can be determined from the breakpoint in the water index–habitat index curve, which is similar to the slope method to determine minimum ecological flow from wetted perimeter–discharge curve. However, the general multi-objective programming model is superior to the slope method in its physical meaning and calculation method. This model provides a general analysis method for ecological water uses of different inland water bodies, and can be used to define minimum ecological flow or water level by choosing appropriate water and habitat indices. Several commonly used flow or water level assessment methods were found to be special cases of the general model, including the wetted perimeter method and the multi-objective physical habitat simulation method for ecological river flow, the inundated forest width method for regeneration flow of floodplain forest and the lake surface area method for ecological lake level. These methods were applied to determine minimum ecological flow or water level for two representative rivers and a lake in northern Xinjiang of China, including minimum ecological flow for the Ertix River, minimum regeneration flow for floodplain forest along the midstream of Kaxgar River, and minimum ecological lake level for the Ebinur Lake. The results illustrated the versatility of the general model, and can provide references for water resources planning and ecosystem protection for these rivers and lake.