Abstract:The soil physical & chemical properties under different patterns of slope land used in Gaozhou county, Guangdong Province, were studied. The result showed that vegetation with lower coverage had high soil bulk density and water runoff, the soil pH in nature vegetation patterns was lower than that in the agricultural patterns slightly. The low quality vegetation had negative effects on soil fertility. It was revealed that factors influencing organic matter content, nutrient supply, soil vegetation cover and soil compaction are critical for soil degradation, and agroforestry systems appeared to have the ability to improve soils quality in degraded hillside ecosystems.

Abstract:The main problems of land resources use in Zengcheng were pointed out. According to the deviations in its natural geography features, current situation and development direction etc., the landuse of Zengcheng was distinguished into three kinds of development models ,including town agglomeration district model, cultivated land opening district model and ecological construction district model, which should be performed with different development strategies based on the fundamental principles for the sustainable use of land resources. some suggestions to promote the level of land resources sustainable use were provided.

Abstract:以甲醇作为有机改性剂 ,30mmol·L-1NaOH + φ(甲醇 ) 15 %为淋洗液 ,建立了菜豆有机酸和无机阴离子同时分析的离子色谱法 .结果表明 ,该方法能同时分析菜豆根部和叶部乙酸、琥珀酸、柠檬酸、NO3-、NO2 -、Cl-、SO4 2 -、PO4 3 -等物质 ,其检测限为 0 .0 2～ 0 .40mg·L-1,线性工作范围为 2～ 12 0mg·L-1之间 ,相对标准偏差低于 10 % ,相关系数在 0 .935 4～ 0 .9984之间 ,样品加标回收率为 (10 0± 10 ) % .与Na2 B4 O7或Na2 CO3/NaHCO3 作淋洗液相比 ,该法准确、方便、快速且不受干扰 ,测定结果令人满意

Abstract:Pot experiment was conducted to study the effects of nitrogen and potassium on the yield, quality and physiology indices of garden sass. The results indicated that the yield, nitrate content of plant and chlorophyll concentration of leaf were increased with increase of nitrogen application rate at the range of 0-0.32 g/kg, but the soluble sugar content was significantly decreased at the same time. The available photosynthesis rate of leaf and free amino acid content of plant were gradually increased at the range of application rate of 0-0.16 g/kg and then gradually decreased at the range of application rate of 0.16-0.32 g/kg. Under the experiment condition and with nitrogen application rate of 0.24-0.32 g/kg , applying potassium has specified roles on increasing yield, improving quality as well as decreasing nitrate content.

Abstract:探讨了氧化剂和还原剂对离体荔枝果皮色素苷颜色及稳定性的影响，结果表明：氧化剂可显著促进荔枝果皮花色素苷的降解，花色素苷由红色迅速变为褐色，当pH值升高时，这种作用更显，还原剂不能抵消氧化剂的破坏作用，反而促进花色素苷的降解，导致花色素苷褪色，Na2S2O7可提高花色素苷的稳定性，形成花色素苷SO^-3复合物，可见，荔枝采用后果皮累积的活性氧对花色素苷的降解作用可能与果皮褐变具有密切关系。

Abstract:Effects of relevant factors on anthocyanin synthesis in the pericarp of litchi ( Litchi chinensis Sonn. cv. Feizixiao) was studied. The results showed that before coloration, both soluble sugar and anthocyanin increased rapidly, and sugar might initiate anthocyanin synthesis. PAL did not appear to be the key enzyme for anthocyanin synthesis. The effect of pH on anthocyanin synthesis was complex and further study is required.

Abstract:探讨了卡那霉素 (Kan)、羧苄青霉素 (Cb)、头孢霉素 (Cef)和氨苄青霉素 (Amp) 4种抗生素对台湾青枣幼嫩茎段和疏松的愈伤组织生长的影响 ,初步确立了对台湾青枣 (ZiziphusmauritianaLam .)进行农杆菌介导的遗传转化研究中的抑菌和转化体的筛选策略 .Kan 75mg·L-1时 ,5 0d后茎段基本停止生长并开始变成白色 (白化 ) ;Kan2 5mg·L-1时 ,胚性愈伤组织生长受到明显的抑制 ,Kan 5 0mg·L-1时 ,其生长基本停止且开始褐变 ,Kan 75mg·L-1以上时胚性愈伤组织完全变褐 .适当浓度的Cb或Cef对芽的伸长生长有一定的促进作用 ,Cb +Cef却对芽的伸长出现轻微的抑制效应 .Amp对茎段生长有抑制作用

Abstract:According to an investigation, there are 36 species,including national perserved species- Cyathea spinulosa Wall, under 20 families of medicinal fern plants in Shenzhen city. At the same time, the whole medicinal fern resources has been analyzed in this area.

Abstract:The larvae of Pieris rapae L. topically treated with acetone extracts of the leaves of Tephrosia vogelii Hook f. or rotenone developed into the malformed larvae and pupae. The ultra structure of the integument of the malformed larvae and pupae were observed. It was found that the deformation caused by rotenone and its analogs mainly resulted from the influences of decomposition of the old cuticle and synthesis of new cuticle. Significant differences in content of the chitin, total fats and total proteins between the treatment and control occurred.

Abstract:A series of laboratory bioassays was conducted to determine the effects of various operational factors on the deposition and the responses of 2nd instar larvae of tobacco cutworm, Spodoptera litura , to three insecticides, chlorpyrifos, methomyl and beta cypermethrin in the petri dish Potter tower method. Settling time could affect the deposition. Toxicities of chlorpyrifos on the tested insects were not significantly different between 15, 30, 60, 120 s settling times. The spray volume (0 5-4 0 mL) and pressure (25-200 kPa) significantly influenced the deposition and the responses of tobacco cutworm to insecticides. For the three insecticides, LC 50 of a 4 0 mL spray volume was 11, 3 and 5 fold more toxic than that of a 0.5 mL spray volume, respectively. However, the influences of pressure on the deposition and LC 50 were not so serious as volume, and the difference of between pressures was less than 2 fold. The optimal spray conditions in Potter tower method were suggested.

Abstract:广东省供港菜场小菜蛾对阿维菌素的抗性有逐年上升趋势，1992年抗性为2倍，1994年为12倍，1996年达20倍，广州内陆菜区与供港菜场1992和1999年小菜蛾对几种蔬菜常用药剂的抗性对比表明，2个菜区小菜蛾对阿维菌素，Bt制剂及昆虫生长调节剂定虫隆的抗性均有较大幅度地提高，而供港菜场小菜蛾的抗性更强，对敌敌畏，灭多威，氰戊菊酯及杀螟丹等有机化学农药的抗性，1992年1999年则差别不大，象氰戊菊酯这样近年较少使用的药剂，抗性有减弱的迹象，抗Bt品系小菜蛾对阿维菌素无交互抗性，对阿维菌敏感的小菜蛾在阿维菌素的选择压力下亦会产生抗性，连续选育20代，抗性倍达11．55倍，用阿维菌素选育的抗性品系对定虫隆产生了明显的抗性，说明它们之间存在交互抗性。

Abstract:Three new fungal diseases on Araceae in China were identificated by systematic investigation carried out from 1997 to 1999 in Guangzhou region. The pathogens are Cylindrocladium spathiphylli Schoulties et al. on Spathiphyllum kochii, Puccinia paullula f. sp. monsterae H. Sydow & P. Sydow on Monstera deliciosa and Phomopsis sp. on Homalomena occulta. The list of fungal diseases on Araceae in Guangzhou region was given.

Abstract:Citrus white scaled lesion is a disease producing white spotted, linear, branched, circular or irregular scaled lesions on peel, simply causing epidermal cells putrescence. The pathogens were identified as Colletotrichum gloeosporioides Penz, Botryodiplodia theoboromae Pat. and Alternaria citri Ell.et Pierce, which infected citrus fruits independently or mixedly. The diseased trees in the field were an important resource of the pathogens. The disease started in the middle of May. The peak of infection was in the middle of July. The resistance of Pengnuo navel orange to the disease was the highest among the tested citrus species (varieties). The incidence of disease could be greatly decreased by covering fruits with bags. The better control efficiency (up to 60%) could be obtained by spraying lime sulfur.

Abstract:By using ordinary corn and super sweet corn as test sample,the activities of sucrose synthetase and sucrose phosphate synthetase were studied at plumule stage, three leaf stage and five leaf stage. The result indicated that the activities of sucrose synthetase and sucrose phosphate synthetase increased gradually with the process of growing .In addition,the activities of two enzymes in super sweet corn were higher than those in ordinary corn.

Abstract:采有穗茎注射，花粉管通道法，将大豆总DNA导入春小麦品种宁春四号和宁春16号，引起受体小麦穗长，穗粒数，粒型和化学品质等性状的广泛变异，对变异株进行筛选，获得了比受体蛋白质量提高2．0%-5．5％的变异株系，平均变异率为3．5％，SDS－PAGE结果显示变异株新增加的蛋白质相对分子质量的78．5，0，33．7的组分。

Abstract:用 5 0～ 40 0mg·L-1的二氯苯醚菊酯 (PER)处理黄瓜幼苗 48h ,叶绿素 (Chl)总量、Chla、Chlb、原Chl分别比对照下降 5 .5 5 %～ 46 .43% ,5 .94%～ 48.87% ,4.2 8%～ 38.5 3%和 4.43%～ 30 .5 4% .其相关系数分别是 - 0 .9887,- 0 .9897,- 0 .983 1,- 0 .992 0 .用 2 5 0mg·L-1的PER处理 6d后 ,Chl总量、Chla、Chlb、原Chl和类胡萝卜素含量分别下降 41.6 2 %、43.30 %、36 .6 2 %、2 7.84%和 36 .47% .用 5 0～ 35 0mg·L-1的PER处理黄瓜幼苗 48h后 ,叶绿素酶活性比对照升高 4.72 %～ 2 2 .6 1% ;而δ 氨基乙酰丙酸 (ALA)合酶和ALA脱水酶活性分别比对照下降 8.0 7%～31.92 %和 3.30 %～ 2 9.77% .讨论了PER影响Chl含量的可能机理

Abstract:研究了以壳聚糖微球为载体固定化木瓜蛋白酶的特性，包括其形态，外观和酶学性，结果表明：壳聚糖微球固定化木瓜蛋白酶是粒径分布范围较均匀的球形微粒，固定化酶的表现米氏常数K^appm(酷蛋白）为0.055%，是溶液酶的米氏常数Km的0．13倍，最适pH为8．0，pH稳定性在7．0左右，热稳定性在15－35℃范围内，操作半衰期为25d，该结果为壳聚糖微球固定化木瓜蛋白酶酶反应器的测试和研究提供了重要的参考价值。

Abstract:以壳聚糖和丝素2种高分子物质溶液了适比例混合，再加入戊二醛后，在聚乙烯薄膜上均匀涂布，真空干燥成合金膜，并对合金膜的外观，溶 胀度，酶固定化效果等性状做了研究，结果表明，壳聚糖－丝素合金膜的柔韧性好，在不同pH值下的溶胀度稳定，具有亲水性强，含游离氨基多等优点，是固定化酶尤其是固定化荷电负性酶的优良载体。

Abstract:Investigations were carried out on the wide cross of Chinese orchids and the germination of their hybrid seeds using the orchids of Cymbidiums, Phalaenopsis and Oncidium as materials. The results showed : (1) the fruit set ratios of combinations made with different Chinese orchid species were over 95%; (2) in combinations of Cym.sinense and Cym. hybrids , the fruit set ratios and the amount of seeds per fruit were different with the cultivars of Cym. hybrid and their reciprocal crosses; (3) the fruit set ratios were lower and the amount of seeds per fruit were less when crossing Chinese orchids with other genera orchids; (4) different kinds of hybrid seeds formed different kinds and amount of intermidiate propagule , the hybrid seeds from combinations of Cym.sinense and Cym. hybrids formed protocorm like body, while others formed rhizome; (5) about 10 000 seedlings were produced through protocorm like body and rhizome pathway; (6) the wide cross breeding of Chinese orchids and the hybrid seedlings production were discussed.

Abstract:Pollen morphology of 9 species and 1 variety in section Paracamellia was observed and compared by means of light microscope(LM) and scanning electron microscope(SEM). the morphology of pollen grains in this section is mostly unanimous, showing that it is a natural group; According to exine sculpture character, pollens of the section are divided into two types: foveolate reticulate, rugulate fossulate; The classification problem of C. shensiensis and C. microplhylla was also discussed.

Abstract:Seventy two laying hens, 25 weeks of age, were randomly allocated into 3 groups and fed with diets containing 5.09,10.09,55.09 mg/kg chromium respectively for 4 months. Egg yield was observed. Estrodiol(E 2), progesterone(P) and luteinizing hormone(LH) were determined by radioimmunoassay ( RIA).Follicular cells were cultured with pituitary cells or hypothalamus extracts. Different dosages of chromium were added to the culture medium to observe the influence of chromium on concentrations of E 2 or P secreted by in vitro cultured follicular cell F 3 and F 1 respectively. The results showed that the rations containing 10.09 mg/kg chromium suited the hens better and enhanced egg productive ratio so as to prolong the laying peak period (>90%) . Proper concentration of chromium could directly affect the secretion of E 2 by follicular cells to a significant extent ( P <0.01) .The mechanisms concerning how chromium affected the endocrine activity of laying hens as well as the association with the metabolism of glucose and lipids were also discussed.

Abstract:7头健康杂种,安照随机拉丁方设计，进行静注，肌注及内服沙拉沙星（5mg/kg）的药动学研究，30只艾力肉鸡，随机平均分为3组，分别进行静注，肌注及内服沙拉沙星（10mg/kg)的药动学研究，反相高效液相色谱法测定猪，鸡血浆中沙拉沙星的浓度，统计矩原理处理血浆药物浓度－时间数据，健康猪，鸡给药后的主要药物动力学参数分析结果表明，两种动物间药动学参数存在显著差异，沙拉沙星在鸡体内较猪体内吸收更迅速，分布更广泛，消除更快。

Abstract:The traditional design of the transplanting mechanism of rice transplanters utilized only a single mechanism,which satisfied only requirements for the assigned movement locus of the seedling claw and the angles of rice pulling and transplanting. To design a good transplanting mechanism, the movement locus of the seedling claw, the angles of rice pulling and transplanting, as well as the working speeds of the seedling claw in various key positions and working stages should all be taken into consideration. Therefore, this paper endeavours to prove the feasibility of using a combination of mechanisms to improve the performance of rice transplanters.

Abstract:The respective characteristics and the interactions of ten polysaccharides hydrocolloids were studied in this paper. The result indicated some synergistic interactions between some hydrocolloids. Complex xanthan and konjac gum showed synergistic thickening and synergistic gelating. When xanthan/konjac gum was 8/2, the system could achieve the maximum gel strength. Complex konjac gum and carreeganan could form gel with high toughness. Guar gum and tragacanth exhibited synergistic thickening, when guar gum/tragacanth was 7/3, the system had the highest viscosity.

Abstract:用0.01kg/L壳聚糖溶液（Ⅰ），含0.01kg/L Vc的0.01kg/L壳聚糖的混合溶液（Ⅱ）和含0.01kg/L Vc,0.002kg/LEDTA的0.01kg/L壳聚糖的混合溶液（Ⅲ）涂膜于荔枝（淮枝品种）果实表面，于室温下放置，结果发现，涂膜比不涂膜（对照）果皮颜色好，烂果率低，质量损失小，呼吸速率低，其中含有Vc的壳聚糖溶液Ⅱ保鲜效果最好，室温下（33－34℃）荔枝的货架寿命延长至3d。

Abstract:利用刚果红以筛选法从芽孢杆菌中筛选到1株产β－甘露聚糖酶的理想菌株，即枯草杆菌（Bacillus subtills)NCIMB 11034。该菌产酶条件以槐豆胶或魔芋胶作为碳源，以酵母抽提物作为氮源，25℃培养27h为宜，该酶最适作用温度60℃，最适作用pH5.4,60℃保温3h酶活性不损失，有较好的应用前景。

Abstract:研究了味精废水菌体蛋白浆料的过滤特性与变气压过滤脱水的主要工艺 .结果表明 :味精废水絮凝分离得到的菌体蛋白浆料为极可压实性物料 ;对絮凝菌体蛋白浆料宜选用型号为 12 0 - 747的涤纶滤布 ;采用 3× 10 4 Pa (90s)→ 7× 10 4 Pa(90s)→ 12× 10 4 Pa(90s)→ 18× 10 4 Pa(30s)的压力调节方式能使菌体蛋白浆料过滤脱水效果提高

Abstract:应用计算机对化学实验“最大泡压法测溶液表面张力”的实验数据进行数据处理，通过对实验数据进行最小二乘拟合，得到正丁醇溶液的表面张力σ和浓度c之间的关系方程，从而求出正丁醇溶液的表面吸附量г。最后通过最小二乘线性拟合，求出正丁醇溶液的饱和吸附量г∞，进而求得正丁醇分子的横截面积SB。