Abstract:On the basis of historic information collected on the dike pond system and field investigation data, the dike pond system of typical region in the Pearl River Delta was studied. Its present main types were summarized, of which the ecoeconomical effects of six typical models were analyzed in detail. The results showed that different models had different features, and the favourable cycle of dike pond system was determined by various economical factors. Owing to the predominant ecoeconomical rationality of the integrative fish farming model and local material utilization models,they are worth widespread popularization.

Abstract:The visualization modeling of maize canopy structure was studied in this paper. Two maize sample plots with different planting density were selected in the field, and four maize plants in each plot were studied. The spatial coordinates of five characteristic points along the coastal line of each maize leaf were determined in situ . A general quadratic equation was proposed to characterize the curvature of maize leaf, and the coefficients of the equation were determined by the method of least square regression based on the observed data, then the structure of maize leaf was modeled by using the computer. The results of visualization modeling of maize leaf structure were consistent with the actual situation of maize grown in the field.

Abstract:Effects of different tillage methods on rice growth and nitrogen use efficiency were studied in a potted experiment using 15 N. The results showed that compared with the conventional tillage, with scattered transplanting, the rice yield decreased by 32.6% and nitrogen use efficiency decreased by 15.6% in no tillage. However, minimum tillage and conventional tillage had the similar rice yield and nitrogen use efficiency.

Abstract:Although ethylene treatment significantly enhanced the polyphenoloxidase (PPO) and peroxidase (POD) activity of lychee pericarp, and to some extent, enhanced the respiratory rate and ethylene production, it did not affect markedly the pericarp browning index and chemical composition of lychee fruit. 1-methycyclopropene (1-MCP) treatment did not significantly affect the PPO and POD activity, respiratory rate, ethylene production and chemical composition of lychee fruit. The results imply that the pericarp browning of postharvest lychee fruit is an unsusceptible physiological process to ethylene and cannot be simply attributed to enzymatic browning catalyzed by PPO and POD.

Abstract:以广东 2号香蕉 (Musasp .cv .GuangdongNo.2 )为试验材料 ,研究了不同成熟阶段用不同浓度 1-甲基环丙烯(1-MCP)处理对香蕉后熟过程的影响 在香蕉成熟的第 1、2、3阶段用 10 ,30 ,10 0 ,30 0nL·L-1的 1-MCP处理 12h后 ,0 .0 3mm厚PE袋包装 ,在 2 0℃下贮藏 ,结果表明 ,成熟第 1阶段的香蕉用 1-MCP处理 ,可有效地延迟其后熟 ,其中以 10 0和 30 0nL·L-1处理的效果较明显 ,可以显著抑制果实的变软 ,延迟呼吸高峰的到来 ,推迟果皮颜色的转黄 成熟第 2阶段以后处理 ,效果不佳 ,且不同浓度处理之间无显著差异

Abstract:以2个耐酸铝不同的菜用大豆品种为材料，研究了不同苗龄大豆在铝诱导下的有机酸分泌及根部铝积累特性。结果表明，耐酸铝大豆品种的15d幼苗明显比敏感品种分泌更多的柠檬酸，但10和20d的幼苗分泌的有机酸却少于敏感品种，5d的大豆幼苗在15μmol/L铝处理下，耐性品种根尖铝含量明显低于敏感品种，但在50μmol/L铝处理下20d苗龄的大豆耐性品种的主根根尖明显比敏感品种积累更多的侣。这些结果表明品种间铝诱导的柠檬酸分泌和铝积累模式存在差异，因此，只是在某些特定生育阶段柠檬酸分泌与耐酸铝性存在相关性。

Abstract:Based on Geographic Information System(GIS) and Internet Technique(IT),the study aimed at creating spatial database and document database of Guangdong Province Soil Resource Information System(GDSIS). The study constituted a coding system of spatial data of soil resource, applying scan and mouse tracing on screen to digitize a vectorgraph of soil feature map, and created a database mode for putting the edaphic document information on the internet. The result will provide database for upbuilding a Guangdong Province Soil Resource Information System.

Abstract:The magnetic susceptibility and its relationship with the total content, DTPA extractable content and activity index of heavy metals of urban soils in Nanjing city were studied. The results showed that the magnetic susceptibility of urban soil was higher, and the frequency-dependent susceptibility was lower as compared with those of natural soil. The measurement of magnetic susceptibility provided a simple, quick means for monitoring the pollution status of Cu, Zn, Pb in urban soils.

Abstract:Three kinds of extracting methods and six kinds of solvents were applied to extract the leaves of Tephrosia vogelii Hook f.. the content of rotenone in the extracts and dry powder of leaves were detected by HPLC. It showed that the content of rotenone in the crude extracts extracted by chloroform with vibrating extraction from purple variety was the highest to 9.70% , and the respond content of rotenone in dry powder of leaves of T. vogelii extracted by acetone with Sohxlet from purple variety was the highest to 0.72%. Moderate polarity solvents such as chloroform, benzene, acetone and ethyl acetate were proper to extract rotenone, while chloroform or acetone used in laboratory and benzene used in factory were appropriate.

Abstract:报道了闹羊花素－Ⅲ对柑桔潜叶蛾、致倦库蚊和柑桔全爪螨的生物活性。结果表明，闹羊花素－Ⅲ对柑桔潜叶蛾幼虫具有较好的拒食作用，处理后24和48h的AFC50分别为266．60和49．35μg/ml；对致倦库蚊3龄幼虫具有很强的毒杀作用，处理24h的LC50为0．85μg/mL；对柑桔全爪螨成虫处理后24h的LC50为346．00μg/mL。

Abstract:测定了不同水稻品种叶鞘内游离氨基酸及草酸的含量，并对草酸对褐稻虱的生物活性进行了测定。试验结果表明：水稻叶鞘内含有21种游离氨基酸，在小粒野生稻中，氨基酸总量及天冬氨酸、谷氨酸、天冬酰胺、丝氨酸、丙氨酸和缬氨酸等6种主要游氨基酸含量分别为4057．9、215．0、308．3、611．8、571．2、192．1和94．7μg/g，均低于感虫品种TN1中的含量。此外，小粒野生稻内草酸含量为0．38mg/g，明显高于感虫品种TN1中的草酸含量。

Abstract:The glucosinolates in vegetables were the main causes that infected the stripped flea beetles (SFB), Phyllotreta striolata (Fabricius), feeding on the host plants. The preference of SFB in the different growth times, organic and leaf location of the same host plant was studied. It showed that the SFB adults preferred the plants with high content of glucosinlates. The relationships between the density of the SFB adults and the content of glucosinlates were highly significant (r=0.967 4, 0.903 0, 0.990 9, 0.796 3, P<0.05) . It showed that there were other factors affecting the preference of SFB.

Abstract:The host plants of Bemisia tabaci (Gennadius) in Guangzhou area, China were investigated from 1999 to 2000. There were 176 species of plant which belong to 46 families as hosts of B.tabaci , and Solaceae Cucurbitaceae, Leguminosae,Cruciferae,Compositae and Euphorbiaceae are the main families of host plant. All the plants were identified and divided into 4 grades according to the damage degree caused by B.tabaci.

Abstract:研究了常温贮藏过程中 ,曲霉 (Aspergillusspp .)及穗霉 (Spicariasp .)侵染对银杏 (GinkgobilobaL .)种子采后生理的影响 .结果表明 :在 2 5℃ ,RH85 %的条件下 ,接种侵染的银杏种子的病害症状各不相同 .接种第 18d ,与CK组比较 ,各接种组的呼吸强度 (RI)增加了 198.4～ 5 6 4.7mg/ (kg·h) ,相对电导率 (REC)增加了 8.91%～ 18.5 5 % ,失水率增加 32 .0～ 2 12 .6g/kg ,达到极显著差异水平 (P <0 .0 1) .Spicariasp .组的RI、膜透性和失水率均大于Aspergillusspp .组 .上述 3项生理指标上升的快慢是不同步的 ,因不同病原菌而异 .接种 12或 15d时 ,接种组淀粉和蛋白质相对含量均高于CK组 ,并达到显著差异水平 (P <0 .0 5 ) .

Abstract:Improved PEG embedded section method was described. The method made it easy to operate and the results were obviously clearer. Ovaries of rice were conducted by fixing, dehydrating, embedding by PEG in small centrifuge tube, cutting section by razor, vacuum gluing section, labeling by fluorescence antibody, and then microtubules in embryo sac were observed and photographed by confocal laser scanning microscopy. The former gluing section methods (such as poly lysine gluing section method) blocked severely the conjuncting between microtubules and antibodies, vacuum gluing section method being founded by us resolved the problem, the new gluing section method was the main reason leading to improvement of results. One most obvious feature of vacuum gluing section method was without sticker. The method resolved all problems caused by sticker, and the method was suitable for the situation that needed gluing section but sticker blocked the later conducting,and the method was possible to be widely used in other researches.

Abstract:The genomic DNA polymorphism of five mutants, selected from rice variety Texianzhan13 seeds which had been flown on a recoverable satellite, was analysized by using 299 rice SSR(simple sequence repeats) primer pairs selected throughout the 12 chromosome of rice genome. The results indicated that the polymorphism among mutants and origional variety was various. The polymorphic frequency, based on the ratio of number of primers amplifying polymorphic band pattern to the number of amplifying any bands, was 0.35% to 2.47% in different mutants.

Abstract:注射大肠杆菌E .coliK12 D31诱导的柞蚕滞育蛹在 2 5℃温育条件下 ,蛹体血淋巴可产生一系列的抗菌物质以抵御外源病菌的入侵 .本研究以脂肪体为材料 ,诱导后提取组织总RNA ,纯化mRNA并用AMV逆转录酶合成cDNA .设计并合成抗菌肽A基因 (cecA)的引物 ,通过PCR法扩增获得柞蚕抗菌肽基因 ,克隆至pBluescriptM13(+)质粒 ,获得相对分子质量 5 .9× 10 4 的融合蛋白表达产物 ,序列分析表明柞蚕抗菌肽A基因及其编码的氨基酸和天蚕具有一定的同源性 .

Abstract:Under NaCl stress, seeds soaked with proline enabled to increase the rate of gremination of corn, the content of water and proline , and the activity of POD and SOD in corn seedling could be improved. The results showed that seed soaked with proline can promot seed germination and seedling growing of corn under NaCl stress.

Abstract:A more detailed comparative study was carried on the leaf form and structure of Saccopetalum prolificum,Miliusa chunii, M.sinensis,M.tenuistipitata and M.balansae.The results showed that in Saccopetalum prolificum, the leaf form, the shapes of epidermal cells,the types of crystal in epidermis,the structure of mesophyllous tissue,the distribution and density of oil cells,and the pattern of vascular tissue in the midrib and so on were very similar to those in 4 species of Miliusa.Therefore, this surported the viewpoint that the Saccopetalum was reduced to the Miliusa and Saccopetalum prolificum was changed into Miliusa prolifica.

Abstract:试验选用30、60、90日龄粤黄鸡各30只，捕杀后取脾脏，除去外周结缔组织及被膜，用匀浆透析法提取脾脏小分子活性物质，经Sephadex G-25凝胶柱层析系统进行柱层析，采用氨基酸自动分析仪分析各组分的氨基酸组成，并通过紫外光吸收光谱来进行扫描光谱分析。结果表明：鸡脾脏小分子活性物质提取液经Sephadex G-25柱层析可分离到3个峰，各峰理化性质存在差异；不同日龄鸡脾脏小分子活性物质的同一组分所含氨基酸各类基本相同，但不同组分之间的氨基酸的含量和组成存在差异。

Abstract:用RT－PCR一步法扩增了华南地区野毒NDV WS99株的HN基因890bp片断，并对其进行克隆、核苷酸测序及同源性分析。结果表明：WS99株的HN基因与其他29株NDV的核苷酸同源性在88．0％－99．8％之间，氨基酸同源性在90％－97％之间。鸡源NDV WS99株与鹅源副粘病毒GPMV株有极高的同源性，高达99．8％。该毒株与TEX／48和B1／47一样，在HN基因1301bp处由G突变为A，对应氨基酸由V突变为I，但其半胱氨酸位点和个数没有改变，且所克隆的目的片段中含有HN基因上5个凝血抗原位点其中的4个。

Abstract:Anaesthesic efficacy of Lumianning on the Family Felidae was observed and evaluated in Siberian tiger, Bengal tiger, jaguar, leopard, black panther and lion. Results showed that Lumianning manifested good sedative, analgesic and muscle relaxant effects and with minor side-effect.The dosages used did not differ between tigers and panthers ( P >0.05 ), but there were significant difference between those used on lions versus tigers and leopards ( P <0.01).

Abstract:Targeting the shortcomings in the traditional designing of the high speed crank-rocker style rice transplanter linkage mechanism, a flexible dynamic analysis of the mechanism, with the optimization of design method, was put forward in the article.

Abstract:牛乳酪蛋白经胰蛋白酶水解，对水解物进行氨基氮含量、水解度（DH）和游离氨基酸含量等测定，并通过SDS－PAGE电泳及Sephadex-G50凝胶层析，分析了相对分子质量的分布。结果表明，在水解条件为底物质量浓度50g/ml、pH7．4、温度45℃、酶量（m)：底物量（m）＝1：1000时，DH随时间延长而增大，水解前期DH增长迅速，3h后增长缓慢，6．0h的DH为20．48％。水解物中必需氨基酸含量约占游离氨基酸总量的73％－80％，此含量随水解时间的延长略有降低；水解物相对分子质量随DH的升高有所减小，经2－3h水解的产物，相对分子质量分布主要集中于2500－3400范围。

Abstract:The antioxidant activity of essential oil from flavelo and extracts from mesocarp and seed of Shatian shaddock in linoleic acid system was investigated by ferric thiocyanate method. The results showed that the inhibition of linoleic acid peroxidation of diethyl ether extract from mesocarp (DEEM) and ethyl acetate extract from seed (EAES) was w = 99.17 % and 92.55% respectively. The antioxidant activity of DEEM was higher than that of BHA and EAES was as high as BHA. The inhibition of linoleic acid peroxidation of essential oil was w =55.24%. The study results proved that antioxidant activity of DEEM and EAES was correlated with total phenolic compounds contained in them.

Abstract:A new simple and effective method for solving ill conditioned linear systems is presented in this paper. This method tried mainly not to decrease the error caused in direct solving, instead, it tried to transfer this error to a medium variable. An algorithm based on this method was presented, and examples showed that this algorithm could solve extremely ill conditioned linear systems correctly and stably.