慈溪市蔬菜农药残留量调查分析

通过对慈溪市无公害蔬菜生产基地和散户生产的叶菜类、果菜类、豆菜类的农药残留量进行了2年抽样检测，检测目标包括10种有机磷类农药和6种拟除虫菊酯类农药。了解慈溪市蔬菜中农药残留量的现状，分析了影响蔬菜农药残留量的主要因素。抽查样本中农药残留量检出率为14．08％，残留量超标率为4．69％。其中无公害蔬菜生产基地蔬菜残留量检出率为6．99％，超标率为0．70％，显著低于散户蔬菜的检出率（28．57％）和超标率（12．86％）。在16种检测的农药中，甲胺磷、毒死蜱、氯氰菊酯、联苯菊酯的检出率和超标率明显高于其它农药。叶菜类的检出率为21．35％、超标率为7．87％，明显高于果菜类和豆类菜。从时间上看，农药残留并无明显的季节变化。综合各方因素，散户蔬菜是影响慈溪市蔬菜农药残留量安全的主要原因。     

Model Establishment for Simulating Soil Organic Carbon Dynamics

Assuming that decomposition of organic matter in soils follows the first-order kinetics reaction,a computer model was developed to simulate soil organic matter dynamics. Organic matter in soils is divided up into two parts that include incorporated organic carbon from crop residues or other organic fertilizer and soil intrinsic carbon. The incorporated organic carbon was assumed to consist of two components, labile-C and resistant-C. The model was represented by a differential equation of dCi/dt = Ki× fT × fw × fs × Ci ( i = l,r, S ) and an integral equation of Cit = Cio × EXP ( Ki X fT X fw X fs X t ). Effect of soil parameters of temperature, moisture and texture on the decomposition was functioned by the fT, fw and fs, respectively.Data from laboratory incubation experiments were used to determine the first-order decay rate Ki and the fraction of labile-C of crop residues by employing a nonlinear method. The values of K for the components of labile-C and resistant-C and the soil intrinsic carbon were evaluated to be 0. 025,0. 080 × 10-2 and 0. 065 ×10-3d-1, respectively. The labile-C fraction of wheat straw, wheat roots, rice straw and rice roots were0.50, 0.25, 0.40 and 0.20, respectively. These values are related to the initial residue carbon-to-nitrogen ratio ( C/N) and lignin content.     

环太湖典型丘陵区不同土地利用下土壤磷素随地表径流迁移特征

在环太湖丘陵地区选择4种有代表性的土地利用类型进行野外原位试验，研究了自然降雨条件下磷素随地表径流的迁移特征。结果表明，各场降雨水相总磷的“次降雨径流平均浓度”呈对数正态分布。悬浮颗粒态磷是水相磷素迁移的主要形态，占水相总磷的76%～89%，其浓度主要由表土总磷含量及地表径流量决定;而溶解态磷（DP）主要与表土中的有效磷含量以及径流与表土相互作用深度有关。溶解态无机磷（DIP）占溶解态磷的57%～85%，竹林的DIP浓度最高。菜地径流的有机磷含量（DOP）明显高于另外3种土地利用。不同土地利用下溶解态和悬浮态磷的迁移通量分别为23～92.7mg·m^-2·a^-1和113.4～364.3mg·m^-2·a^-1，与地表径流量表现出较强的相关性。     

脱氮型生物反应器填埋场中生活垃圾的稳定化研究

    研究了填埋垃圾上层间歇曝气充氧或渗滤液回流前经好氧、硝化反应器处理的生物反应器填埋场系统中渗滤液的脱氮效果及其填埋垃圾的稳定化过程.结果表明,填埋垃圾上层间歇曝气充氧的生物反应器填埋场系统渗滤液NH4+-N浓度的衰减速度虽然比渗滤液回流前经好氧、硝化反应器处理的生物反应器填埋场系统慢,但其理论能耗可比后者节省98%左右,并且无需好氧、硝化反应器的基建投资和污泥处理.此外,填埋垃圾上层间歇曝气充氧的方式加快了填埋垃圾和渗滤液中有机物的降解,提高了填埋垃圾的稳定化效果,增加了10%～12%的沉降高度.而渗滤液经过好氧反应器处理后回流到填埋场,将会引起填埋垃圾降解后期碳源供应不足,减慢垃圾的稳定化过程.填埋垃圾上层间歇曝气充氧的生物反应器填埋场系统由于其中的反硝化作用有机物的消耗及好氧微生物的代谢活动,其渗滤液CODCr和VFA最大浓度仅为对照的50%,并且产甲烷反应器的产气量也减少了42%～44%.     

鸡新城疫病毒F蛋白部分表位基因的克隆表达及其免疫反应性

为研究NDV-F蛋白抗原表位在动物免疫应答中的作用特点,作者克隆和表达了NDV-F蛋白基因的部分片段,并检测其免疫反应性.首先根据F基因和载体pGEX-4T-1的多克隆位点自行设计了1对引物,以已克隆的NDV(F48E9株)的F基因为模板,通过PCR扩增获得长度为594 bp的片段.接着在电泳和酶切鉴定后将其定向插入pGEX-4T-1,构建重组质粒pGEX-4T-1-F594,并经PCR、双酶切及测序鉴定后,进一步将其转化到大肠杆菌BL21中.最后用IPTG诱导表达,提取物用SDS-PAGE和Western-blotting分析.结果表明,该基因片段表达的融合蛋白大小约为46 000,以包涵体形式存在,并具有良好的免疫反应性.     

杂交水稻产量与品质形成的发育生理与遗传生态学研究

总结了福建农林大学农业生态研究所十多年来有关杂交水稻籽粒灌浆过程所涉及到的干物质积累与分配、强弱势粒发育进程的颖果形态解剖结构及其相关酶活性、激素含量的变化和强弱势淀粉积累动态等发育生理, 以及在不同生态条件下,籽粒发育的动态遗传特性和胞质负效应对杂交水稻籽粒灌浆相关过程的影响等遗传生态学的研究成果,并就目前杂交水稻产量与品质形成研究中存在的问题做一阐述,在此基础上提出了今后作物栽培学研究的新方法与新思路。     

Simulation and Prediction of Soil Organic Carbon Dynamics in Jiangsu Province Based on Model and GIS Techniques

Based on the databases of soils, meteorology, crop production, and agricultural management, changes in the soil organic carbon (SOC) of agro-ecosystems in Jiangsu Province were simulated by using a soil organic carbon model with a linkage of GIS. Four data sets of soil organic carbon measured from various field experiments in Jiangsu Province were used to validate the model. It was demonstrated that the model simulation in general agreed with the field measurements. Model simulation indicated that the SOC content in approximately 77% of the agricultural soils in Jiangsu Province has increased since the Second National Soil Survey completed in the early 1980s. Compared with the values in 1985, the SOC content in 2000 was estimated to increase by 1.0-3.0 g kg-1 for the north and the coastal areas of the province, and by 3.5-5.0 g kg-1 for the region of Tai Lake in the south. A slight decrease (about 0.5-1.5 g kg-1 ) was estimated for the central region of Jiangsu Province and the Nanjing-Zhenjiang hilly area. Model prediction for 2010 A.D. under two scena-rios, i.e., with 30 and 50% of the harvested crop straw incorporation, suggested that the SOC in Jiangsu Province would increase, and thus that the agricultural soils would have potential as organic carbon storage. The incorporation of crop straw into soils is of great benefit to increase soil carbon storage, consequently to benefit the control of the rise of atmospheric CO2 concentration and to maintain the sustainable development of agriculture.     

四种李属彩叶树种枝叶花色苷分布的解剖研究

对紫叶桃(Prunus persicaf.atropurpurea)、美人梅(Prunus mume ‘Meirenmdi')、紫叶矮樱(Prunus×cistena ‘Pissardii')、紫叶李(Prunus cerasifera ‘Pissardii')等四种核果类紫叶树种一年生枝条、叶柄、叶片中花色苷的分布状况进行了切片研究,并对这几种树种的外观形态区别做了比较描述。结果发现四种植物的花色苷在枝干、叶柄中各组织的分布位置从枝条梢部到基部色素含量递减,除紫叶矮樱外,其他树种枝条次生木质部均无花色苷分布,不同树种各部位的色素分布及组成各异。花色苷在叶片中的分布范围与花色苷含量呈正相关。从四种彩叶植物色彩的年变化来看,花色苷在枝叶组织中分布越广泛,彩叶植物叶色季节间变化越小,受环境等变化的影响也越小。     

Isolation and Characterization of the Wheat cDNA Fragments Involved in salt Stress

cDNA-AFLP(amplified fragment length polymorphism) is used to isolate genes differentially expressed in salt-stressed and unstressed wheat lines RH8706-49 and H8706-34 derived from a single seed,representing a salt-stress resistant (SR) and salt-stress sensitive(SS) line,respectively.About 88.1% cDNA fragment are expressed in all the four samples,11.9% are different between the samples.68 cDNA fragments were cloned,of which 35 were subject to sequence analysis.Database searches indicate that 11 cDNA fragment show high homology to known genes,which mainly include proteins related to ion transport,signal transduction and oxidative stress.The remaining 24 cDNA show no detectable homology to known genes,suggesting that they probably represent novel genes.