Abstract:The physiological characters of leaf in seedling stage of 8 sugarcane genotypes were studied. The results showed that there was a very significant positive correlation (0.96) between relative growth rate (RGR) and net assimilation rate (NAR) during seedling stage. Both RGR and NAR had a negative correlation with cane juice sucrose and positive correlation with cane yield. Path analysis indicated that the NAR had directly positive contributions to cane juice sucrose and cane yield. The results showed that these physiological characters of seedling, such as higher value of NAR, LAR and chlorophyll a/b, can be used as indirect selection indices for higher yield and higher sucrose content of cane.

Abstract:The effects of Penshibao, one of plant nutritional regulator on the seed germination and seedlings growth of peanut under different temperatures were studied. Peanut seeds soaked with different concentrations of Penshibao (P.S.B) increased germination rate, the length of radical as well as its diameter under different temperatures. The germination ratio was in the highest when concentration was 1 000 mg/L; the increasements of radical length and its diameter were the most significant when concentration was 300 mg/L. P.S.B also stunted seedlings growth, increased branching numbers, the mass of the aerial part, and the content of leaf chlorophyll, protein and dissolvable sugar.It also promoted the leaf nitrate reductase activity and the root activity of seedling. For aerial part ,the better concentration was 300-500 mg/L .Besides, it also increased the elongation of taproot,its diameter, amounts of nodules and seedling fresh mass. The best concentration for the elongation of taproot was 100-300 mg/L.

Abstract:Allelopathic potentials of the root exudates from peanut (Arachis hypogaea) on rice, maize, radish and rye grass were investigated. The results showed that the root exudates from peanut promoted the seedling growth of tested crops. Further research revealed that the root exudates from peanut were water-soluble materials which contain triacontanol. The promoting effects on crops had difference at different concentrations of the root exudates from peanut.

Abstract:The characters of grain filling and flag leaf senescence of rice raised and transplanted by different ways viz. dry-land raised and hand transplanted rice (DHR)?plastic plate raised and throwing rice (PTR) and wet-land raised and hand transplanted rice (WHR) were studied. WHR had the longest active growth day (D) , but it had the lowest mean growth rate ( G m) and initial growth potential ( R 0), flag leaf senescence rate and grain filling were slower in early days, faster in late days, respectively. DHR had the highest R 0 and G m and the shortest D , flag leaf senescence and grains filling were faster in early days, slower in late days, respectively. PTR grain filling parameters value and flag leaf senescence were always in the middle of the two others. There was a good negative correlation between grain filling and flag leaf senescence.

Abstract:对荔枝果皮花色素苷含量与果皮褐变的关系进行了研究，详细比较了荔枝上两种花色素苷的测定方法，结果表明：随着采后荔枝果皮褐变指数的升高，果皮花色素苷含量显著下降，两者呈现很好的负相关。盐酸甲醇法测定褐变荔枝果皮的花色素苷含量时存在较大的干扰，主要原因是盐酸甲醇将不溶于水的褐色物质也提取了出来，褐色物质的盐酸甲醇溶液在530nm处有较强烈的光吸收，干扰了花色素苷的测定结果。

Abstract:观察了石硖、储良龙眼 (DimocarpuslonganLour.cv .Shixia&Chuliang)在 4和 2 0℃条件下的贮藏效果 ,测定了果肉生理生化变化 .结果表明 :低温能够大大延缓果肉的衰败进程 ,石硖明显比储良耐贮藏 ,储良 33d、石硖 5 0d时果肉几乎全部流汁 .随着贮期延长 ,整果和果肉质量损失率和霉烂率增加 ,好果率降低 ,果皮褐变 .生理生化变化表现为丙二醛 (MDA)含量逐渐增加 ;超氧化物岐化酶 (SOD)活性 (4和 2 0℃ )变化不明显 ,相对较稳定 ,储良活性比石硖低 ;过氧化物酶 (POD)呈上升趋势 ,2 0℃下活性明显比 4℃下高 ;过氧化氢酶 (CAT)活性呈显著下降趋势 ,储良活性明显比石硖弱

Abstract:Concentration and distribution of N, P, K, Ca and Mg in a 11 year old artificial Cunninghamia lanceolata stand on a poor soil were studied. The highest concentration of nutrients was found in leaves and fruits, and N and Ca concentrations were higher than those of other nutrients. Accumulation of five nutrients in soil contributed more than 99% of the total in Cunninghamia lanceolata stand ecosystem. The small leaf amount with a lot of attached dead leaves and branches and bad site condition may be responsible for the low yield of Cunninghamia lanceolata stand.

Abstract:By a systematic investigation, it was found that the soil arthropod in vegetable fields in Shenzhen included 9 orders, 18 families, 35 species of insects, 3 families, 3 species of Acarina, 1 specie of Acariforme and 3 families, 6 species of spiders. The dominant species were Hypogastura commubis Folsom, Onychiurus folsomi Schaffer, and Canestriniidae. According to the analyzed diversity of different soil levels, the species number and arthropod diversity at 5-10 cm depth were high. At the same time, the structures of arthropod species and diversity characteristics in different seasons and vegetable varieties were significant different. The index of arthropod diversity was mainly determined by the dominant concentrator index and species evenness.

Abstract:在寄主植物（苦瓜、丝瓜、豇豆）上，研究温度和寄主植物对瓜蚜的生长发育、繁殖及种群增长的影响。结果显示，瓜蚜在3种寄主上的生长发育和繁殖情况有差异，并随温度而变化，但皆以18℃的种群增长趋势指数（I）最高，分别为6．288、1．297和0．324，寄主选择性实验和控温实验结果一致表明，在3种寄主中，苦瓜最适瓜蚜种群增长，豇豆次之，丝瓜最差。随温度升高，发育历期呈减短趋势，但达到32℃时稍有延长，温度对瓜蚜成蚜的繁殖量和存活时间的影响程度随寄主植物的不同而异。

Abstract:The reproduction strategy of Trichogrammatoidea bactrae Nagaraja was analyzed when the host availability suspended. It was showed that T. bactrae could adjust its reproduction strategy when the host was unavailability in a short period (4 days after emergence). Its oviposition was improved on the first day when hosts were availability, while their reproduction potential and female longevity were weakened. However, T. bactrae' s reproduction potential and female longevity were significantly reduced when host was unavailability in a long period (8 days after emergence). Based on such reproduction strategy of Trichogrammatoidea bactrae , it was helpful to take some protection or augmentation measurements to improve its reproduction potential when host was unavailability in field.

Abstract:研究了12种金属离子对水稻纹枯病菌菌丝生长和菌核形成的影响,按其对菌丝生长和菌核形成有抑制作用的浓度范围不同分为3类(1)对病菌有抑制作用的浓度最高,在2 500μg/mL时,仍有菌丝生长和菌核形成,属于这一类的有Mg2+、Ba2+、Ca2+和Mn2+4种金属离子;值得一提的是,Mg2+在100～2 5μg/mL范围内促进菌丝生长和增加菌核干质量.(2)对病菌有抑制作用的浓度较高,在500或1000μg/mL时可严重抑制菌丝生长和菌核形成,属于这一类的有Fe2+、e3+、Cu2+、Pb2+和Zn2+5种金属离子.(3)在浓度为10或50μg/mL时严重抑制菌丝生长和菌核形成,属于这一类的有Ag+、Hg2+和Cd2+3种金属离子.

Abstract:Twelve species of pathogenic fungi from the weeds in field in Guangdong province were found and described. They were Nimbya alternantherae from Alternanthera philoxeroides,Piricularia grisea from Digitaria adscendens,Pseudocercospora oxalidis from Oxalis corymbosa,P. oenotherae from Ludwigia prostrota, P. avicularis from Polygonum hydropiper,Cercospora beticola from Chenopodium ambrosioides,Septoria centellae from Centella asiatica,Sporisorium lepturi from Hemarthria compressa, Uromyces alopecuri from Alopecurus aequalis,Puccinia paspalina from Paspalum conjugatum,Physalospora commelinae from Commelina nudiflora,and Albugo bliti from Alternanthera sessilis. Among them, N. alternantherae,P. oxalidis,C. beticola and U. alopecuri could be potential mycoherbicides in future.

Abstract:Eucalyptus urophylla Blade MLA clone (MLA) was a difficult to root species. E. urophylla Blade U 6 clone (U 6) and E. ABL 12 W 5 clone (W 5) were relatively easy to root species. The activity of polyphenol oxidase (PPO) in MLA was lower than that in U 6 and W 5. After the cuttings of Eucalyptus were treated with naphthylacetic acid (NAA), the activities of PPO increased regularly in different stages of rooting. The relationship between the oxidase and rooting of Eucalyptus cuttings was discussed.

Abstract:In order to investigate the influence of the VA mycorrhiza isolated from root soil of Litchi on the tissue cultural seedling of Eucalyptus urophylla and Zea mays seedling, the VA preparation was inoculated and a strong growth response of the two plants to the infection of the VA mycorrihizal fungus exist. The result showed that the 3 monthes' inoculated Eucalyptus urophylla seedling was 34.2% higher in height, 21.1% wider in stem diameter and 29.5% more in dry root mass than those of the control and the similar result was obtained in the Zea mays seedling. The vesicles and arbuscules special to the VA mycorrhiza were observed in the cortex cells of the young roots from the inoculated plants but without from the same position of the control. It is suggested that the VA endomycorrhiza improves the growth of the tested plants significantly and has its practical value in development.

Abstract:Light and scanning electron microscopies were used to examine foliar epidermal characteristics of 11 species of Machilus distributed in Hong Kong. Most of these species had simple hairs. The stomatal apparatus is paracytic type with one or two subsidiary on both or either side of the guard cells. Three types of anticlinal walls of lower epidermal cells are recognized: straight, sinuolate or sinuate. Two types of the cuticular process types can be recognized based on their shapes. These epidermal characteristics are taxonomically helpful for the identification of some species with similar leaf morphology.

Abstract:The paper presents the results of a preliminary survey of the wild ornamental plant resource in Gaolan islands, Guangdong Province. According to the results of investigation, a total of 90 famlies, 153 genera and 198 species of ornamental plants were identified in Gaolan islands, including 9 families ,9 genera and 9 species of the Pteridophytes; 3 families ,3 genera and 4 species of the Gymnospermae; 78 families , 141 genera and 185 species of the Angiospermae. Based on the characters and utilizations of the resource, some suggestions about how to rationally exploit and protect them are put forward.

Abstract:Community analysis was made followed by the survey of the vegetation in Shimentai Nature Reserve, northern Guangdong Province's Yingde City. The typical tropical and subtropical families and genera, with Fagaceae, Theaceae, Lauraceae, Elaeocarpaceae, Magnoliaceae, Escalloniaceae, Daphniphyllaceae, Hamamelidaceae, Aquifoliaceae, Styracaceae, Ericaceae, Sterculiaceae, and Pentaphylacaceae being the dominant families, characterize the forest vegetation in Shimentai Nature Reserve. Dominant species are also tropical and subtropical elements, most of which belong to the dominant families. Based on ecological physiognomy and community structure, vegetation of Shimentai Nature Reserve was classified into 8 vegetation-subtypes, i.e., monsoon valley evergreen broadleaved forest, montane evergreen broadleaved forest, subtropical evergreen coniferous-broadleaved forest, montane elfin forest, cliff dwarf scrub, subtropical coniferous forest, subtropical bushy hillside grassland and subtropical bushy mountain slope; and the forest vegetation was further classified into 23 associations. The diverse vegetation, with relevance to the special topography of the protected area, has great value for protection, science and natural heritage. To name only the cliff dwarf scrub, it is significantly important for the research into the initiation and adaptation of plant community and the environmental change in time.

Abstract:Perennial ryegrass was ensiled in 1-L laboratory jars after adding formic acid or sulphuric acid to evaluate the effects of acidifiers on DM loss, acidification, microflora and fermentation characteristics. Jars were 1 L Weck glass jars with 106 days storage period. Results showed that addition of formic acid or sulphuric acid significantly suppressed normal lactic acid fermentation, reduced the yield of fermentation products and remarkably decreased nutrients loss during the ensiling.

Abstract:This paper deals mainly with the interfamily spheroplast fusion of Pasteurella multocida C 48-1 (Enr r,Chl s) and Escherichia coli O 78 (Chl r,Enr s), and the development of 2-combined attenuated strains. Protoplast fusion was performed by mixing protoplast suspension with 400 g/L PEG4 000 and newly formed Ca 3(PO 4) 2, and 16 strains hybrid cells with two drug-resistant markers were selected. To test the immunogenicity and safety of 2 fusion attenuated strains (F 4 and F 9), Guangdong yellow chicks were vaccinated separately with F 4 and F 9.The result showed that the F 4 strain was safe and with immunogenicity attributable to the two parent bacteria.

Abstract:The thymus of the rhesus monkey ( Macaca mulatta) was studied by histological, histochemical and transmission electron microscopic techniques. The results showed that it was surrounded by a capsule continuous with thin connective tissue septa that divided the organ into many lobules, each consisting of cortex and medulla, and most of the medullae connected with each other. There were many mast cells in the capsule and interlobular septa. The cortex mainly consisted of immature T lymphocytes, epithelial cells, some mast cells, and macrophages and, in addition, typical blood-thymus barrier. The medulla was mainly composed of mature T lymphocytes, epithelial cells, also some mast cells and a few macrophages, interdigitating cells, myroid cells, B lymphocytes, plasma cells, eosinophilic granulocytes, thymic corpuscles and thymic cysts.

Abstract:The elastic stress and displacement of the machining area under PCD cutting edge during the superfine cutting was studied theoretically, and the boundary equation between the elastic and plastic area developed. Experiments using PCD cutting tool to cut hard AL and Cu were conducted. The surface of the workpiece obtained was analyzed with SEM method. It was demonstrated that sideways and lengthways plastic transformation were the main factors affecting the roughness of the workpiece surface. the authors suggested that the grinding trace on the rear surface of the tool should parallel the edge.

Abstract:The paper reports a study on the gelling properties of gelatin-carrageenan systems and the effect of pH and electrolytes on them. The results showed that the gelatin-carrageenan system had good gelling ability, the gel strength increasing with the ratio of gelatin to carrageenan between pH 6 to 10, and peaking at the ratio of 5 to 3. In the system where the ratio of gelatin to carrageenan was 1 to 1 and the pH value was 7, gel strength was constant through pH 5 to 11 while the water-holding ability increased with the rise of pH value, and on the contrary, both the melting point and the solidifying point decreased with much temperature rehysteresis between them. The addition of electrolytes at low level could increase the gel strength and the water-holding ability of the mixture of gelatin and carrageenan, while the melting point and the solidifying point of the gel of this mixture increased with the rise in electrolyte concentration with the temperature difference hysteresis between them decreasing continuously. Moreover, the effect of electrolytes on the gel strength was related to the pH value of the systems.

Abstract:对苯甲酸甲酯的合成工艺条件及抑菌效果进行了研究。合成试验结果表明苯甲酸甲醇酯化混合液[n（苯甲酸）：n(甲醇）＝1：5]在85℃时酯化反应速度最快；不同类型酯化催化剂间适当组合对苯甲酸甲酯的合成可产生显著的增效作用。抑菌试验结果表明苯甲酸经酯化修饰后，可显著抑制微生物的生长，缩短对数生长期和减少微生物的生长量。

Abstract:The concept of index loss and regression model were introduced into multi-index experimental uniformly orthogonal designs. A synthetic multi-index loss model based on main components of responding loss variables was built. The model was applied to study the properties of hot water soluble edible film and obtain satisfactory technical coefficients and formulas.

Abstract:提高商品猪的胴体瘦肉率是养猪生产中的重要目标之一 .瘦肉率的提高有赖于骨骼肌的生长 .为了研究各种调控物质对猪骨骼肌生长的作用机制 ,有必要建立猪骨骼肌卫星细胞的体外培养方法 .本试验采用胶原酶消化法从猪半膜肌分离出骨骼肌卫星细胞 ,建立了猪骨骼肌卫星细胞的培养方法 .1　材料与方法1.1　材料试验动物采用 1日龄杜长大仔猪 (由华南农业大学种猪场提供 ) .主要试剂包括ＤＭＥＭ培养基 (Ｇｉｂｃｏ公司 ) ,Ｄ’Ｈａｎｋｓ液 ,胶原酶Ⅱ(Ｓｉｇｍａ公司 ) ,胎牛血清 (Ｓｉｇｍａ公司 ) ,鸡胚浸出液 .1.2　方法将仔猪颈动脉放血致死 ,…

Abstract:植物杀虫剂是近年来迅速崛起的一类新型生物农药 ,具有低毒、低残留、对环境影响小等一系列传统化学杀虫剂所不具备的优点 ;研究和开发植物杀虫剂能较好的解决当前化学杀虫剂带来的各种问题 ,适应了现代化工业生产和现代化农业发展的需要[1] .我国目前已正式登记注册的植物杀虫剂已有烟碱、鱼藤酮、印楝素、川楝素、异羊角扭甙、茴蒿素和茶皂素等 2 0多种 .众所周知 ,杀虫剂对天敌的影响是评价杀虫剂安全性的一个重要指标 ,尽管一般认为植物杀虫剂对天敌安全 ,但长期以来却一直缺乏足够的实验数据支持 .赤眼蜂是重要的天敌昆虫 ,是中国现代…

Abstract:大量试验证明 ,缺硅土壤施用硅肥水稻增产显著[1] ,但有关施硅对稻米品质的影响却鲜见报道 本研究通过盆栽试验初步探讨了施硅对水稻产量及稻米品质的影响 ,为优质稻的生产提供科学依据 1　材料与方法试验设对照 (不施硅 )和施硅 (80ｍｇＳｉＯ2 ·ｋｇ-1) 2个处理 ,5次重复 底肥施用量一致 ,分别为Ｎ 10 0ｍｇ·ｋｇ-1、Ｐ2 Ｏ540ｍｇ·ｋｇ-1、Ｋ2 Ｏ 80ｍｇ·ｋｇ-1 硅肥为Ｎａ2 ＳｉＯ3 · 9Ｈ2 Ｏ (含ＳｉＯ2 2 1 0 % ) ,作基肥一次施用 土壤采自增城市朱村 ,为花岗岩发育的水稻土 ,采样深度为 0～ 15ｃｍ ,每盆装土 13.5ｋｇ 土壤…

Abstract:柑橘胚性愈伤组织具有广泛的研究用途 ,是种质资源离体保存、外源基因转化的理想材料 .柑橘胚性愈伤组织的生长受培养基组成成分影响显著[1,2 ] ,探讨柑橘胚性愈伤组织生长的影响因素将为胚性愈伤组织的长期继代保存提供依据 ,而且生长状况良好的柑橘胚性愈伤组织的获得是进行原生质体融合、外源基因转化及相关生物技术研究的基础 .1　材料与方法　　材料 :华南农业大学生物物理实验室诱导的蕉柑 (Ｃｉｔｒｕｓｒｅｔｉｃｕｌａｔａｖａｒ.ｔａｎｋａｎＨａｙａｔａ)胚性愈伤组织 .培养基 :以ＭＴ为基本培养基 ,添加不同浓度的细胞分裂素 (…

Abstract: