Abstract:Combined RS and GIS technique, the procedure and method of using TM to analyze the dynamics of reclaimed coastal land is studied, and the dynamics of Western Guangdong is analyzed. The results show that: (1) the proposed remote sensing procedure is a simple and suitable method to inspect the dynamics of reclaimed coastal land. (2) Up to 1997, 60 460 hm~2 coastal land had been reclaimed, among which, 47 936 hm~2 before 1987, 12 524 hm~2 after 1988. (3 ) Before 1987 , the reclaimed coastal lands were mainly used for agriculture, it covered 98 .41 % of the total area, and its utilization rate is 73. 71 %. (4) After 1988, the reclaimed coastal land for aquaculture developed rapidly, and the scale of construction was enlarged. The aquaculture land covers 92. 18% of the total agricultural land; 36. 76% higher than those before 1987. The utilization rate was 22. 32% higher than that before 1987. The land area for construction is 1 073 hm~2, and for city construction is 2. 26 times than 1987.

Abstract:Based on the technique of Geographic Information System (GIS), red soil resources (RSR) of Zhejiang province were classified to 84 types by computer - aided overlay analysis and qualitatively evaluated by combination with mathematic models. The agricultural regionalism system and method were advanced and the division was carried out on the basis of classification and evaluation. Six regions and twenty subregions were divided. The characteristics of and strategies for agricultuval use for each region were discussed.

Abstract:The study evaluated land resources of Heyuan city using the theory and method of land capability evaluation. The results indicated: superior and grades land resources were in lack. Most land quality was below average, belonging to and grades. The limited cultivated lands must definitely be protected and improved. Afforestation should be conducted with measures suited to local conditions.

Abstract:Studies were conducted on resistant heredity of cucumber blight through dill crossing with cucumber cultivars either resistant or susceptible to cucumber blight. The results showed that the additive effect was the predominant component., although some dominant effect and epistasis effect were present. Resistance to cucumber blight was controlled by at least 3 pairs of genes. The narrow hereditary capacity is 78%.

Abstract:The pericarp color in litchi was found to be a expression resulting from the effects of various kinds of pigments. The transformation pattern of pericarp pigments in ' Feizixiao' was different from that in' Nuomici'. During the maturation stage of litchi fruits, both the chlorophyll and anthocyanin contents of pericarp in' Feizixiao' were higher than those in 'Nuomici'. The excessively high chlorophyll content in' Feizixiao' pericarp interfered with the red color expression of anthocyanin. On the contrary, it was favorable for the red coloration of anthocyanin that the chlorophyll decomposed rapidly in' Nuomici' pericarp.

Abstract:Feizixiao Litchi, an early-mid-season variety, often forms large and long panicles Which greatly affects its productivity. The duration of the panicle development and the lengths of the main panicles axis were shortened by removing the primary panicles, thinning and short-pruning the secondary panicles, and thus the number of male flowers was reduced, while the female/male flower ratio was increased. As a result of that, the blooming duration of the female functional flowers was prolonged, and the proportion of the fruiting panicles was increased. In conclusion, it was observed that pruning panicles one and a half months prior to first flowering could improve the quality of panicles and their fruit-set in Feizixiao litchi.

Abstract:The source and distribution of organic acids in Shenzhen municipal sludge and their relative stabilities during anaerobic digestion were investigated. Organic acids of bioorigin from domestic wastewater discharge and from indigenous microbe is found to be the main source responsible for the abundant organic acids present in the original sludge. The stability order of organic aids with different structure during anaerobic digestion is found to be: hydroxy acid < unsaturated acid < saturated acid < aromatic acid < steroid acid, which is roughly parallel to their chemical stability order, indicating that the anaerobic digestion of organic acids is mainly a structure-controlled degradation. Organic acids having aromatic ring, conjugated C = C bond and fused ring within their structure are normally more stable. Short chain hydroxy acids are selectively preserved against their long chain counterparts during anaerobic digestion. Anaerobic digestion may, under some circumstances be influenced by microbial metabolism, particularly the preference of carbon source.

Abstract:Selecting cassava monocrop and cassava - Arachis pentoi intercrop systems from 9 different cultivation systems to study the properties of root space variety and soil quality change. The results indicated that there were 86. 8 % and 91. 1 % roots to distribute in the layer of 0 - 40 cm for the cassava monocrop and cassava intercrop systems, respectively. The root biomass of cassava intercrop was 55. 4% greater than that of the cassava monocrop. The coverage of cassava intercrop had been increased by 56. 8% and reduced soil loss 4 times than that of cassava monocrop. The cassava intercrop system was able to improve nutrient uptake by cassava, and get higher nutrient content in the aboveground plant. The cassava intercrop not only improved potassium acquisition by cassava, but also increased available nutrient in each layer and enhanced the capacity of soil nutrient supplying and soil quality.

Abstract:从广东省曲江县蚕区捕捉的黑条灰灯蛾(Creatonotus gungis L.)成虫分离到一种微孢子虫.孢子大小为(3.03±0.17)μm×(1.90±0.07)μm;孢子的血清学类型、超微结构与传统的家蚕微粒子孢子(Nosema bombycis,简称N. b.)有差异;黑条灰灯蛾微孢子虫的发育周期符合Nosema属的特征;对家蚕有中等程度的感染能力,经卵传染频率较低.

Abstract:Based on the data of systematic survey in the field and observation in the laboratory, the natural population life tables of continuous two generations of the diamondback moth (DBM) , Plutella xylostella L., were constructed on one cropping of flowering Chinese cabbage in Shenzheng, Guandong Province. The results showed that the indices of population trend of two continuous generations of DBM were 11. 9 and 24. 4, respectively in spring and autumn. Parasitoids played a determinant role in the control of natural population of DBM. In spring, the important factor influencing the natural population of DBM was the larval-pupae parasitoid, Oomyzus sokolowsakii (Kurdjumov), which exclusive index of population control (EIPC) reached 8. 28. While the EIPC of Cotesia plutellae Kurdjumov was 4. 85. In autumn, C. plutellae was the secondly important factor influencing the natural population of DBM, which EIPC was 3. 67. The low EIPC (1 .2) of O. sokolowsakii caused a high population increase of DBM in autumn.

Abstract:The vegetable beetle Phaedon brassicae Baly is an important pest in South China. The experiment was conducted in field in 1996 and six varieties of vegetable (water cress Nasturtium officinale R. Br., Chinese kale Brassica alboglabra Bailey, leaf mustard Brassica juncea (L. ) Coss var. foliosa Bailey, turnip Raphanus sativus L. flowering cabbage Brassica capestris L. ssp. chinensis var. utilis Tsen et Lee, Chinese cabbage Brassica capestris L. ssp. chinensis (L. ) Makino var. communis Tsen et Lee) were used to study the effects of vegetables on the development, survival and oviposition of vegetable beetle. The results showed that the development duration of the beetles feeding on Chinese hale(28. 36 days) was significantly longer than that on other vegetables while the longest development duration was got on Chinese cabbage. The survival rate of the beetles on Chinese cabbage was 86. 99% while 42. 48% of survival was got on Chinese kale. The vegetable beetle preferred to lay their eggs on Chinese cabbage (124. 10 eggs), but only 1. 70 eggs laid on Chinese hale. It was demonstrated that Chinese cabbage was good for the beetle development, survival and oviposition, but Chinese hale showed an inhibit effects on the beetles.

Abstract:s: Results of experiments in laboratory indicated that the extracts of fruits, leaves and stems from Strophanthus divaricatus possessing strong antifeedant and insecticidal properties on the 4th instar larvae of the imported cabbage worm Pieris rapae. It was found that the LC50 and LC95 of D-strophanthin isolated from Strophanthus divaricatus were 32.046 8 mg/L and 379. 718 1 mg/L respectively, against 4th instar larvae of Pieris rapae. Results in field trials showed that the good effectiveness was obtained with 0. 05% commercial products of Strophanthus divericatus against imported cabbage worm.

Abstract:Insecticidal activity of Daphne tanutica, a local endemic plant from Qinghai-Tibet plateau, was first reported in this paper. The air-dried and powdered plant was extracted with methanol, acetone, ethyl acetate, chloroform, benzene and petroleum ester, and the results showed that foe extractive rate in methanol was the largest (22. 34% ), and the smallest (2. 21% ) in petroleum ester. The crude extracts of former five solvents were proved to possess strongly antifeeding effect on the 3rd instar larvae of tobacco cutworm, Spodoptera litura, through the preliminary bioassay with AFC50s of 108. 72, 111. 69, 102. 14, 71. 15 and 65. 51 g dried powder/L. At concentration of 500 g dried powder/L, antifeedant effect of the petroleum ester extract against the tested insects was 62. 31 %. Therefore benzene was the most effective extracting solvent.

Abstract:Bioactivities of 9 herbicides and 7 admixtures against pink woodsorrel (Oxalis corymbosa DC. ) in city lawm, were systemically determined. The results indicated that metribuzin, atrazine, caoping-2, caoping-3, and glyphosate had high control effectiveness against pink woodsorrel. The control effects were 88.66% - 99. 10% in the 20th day after treatment. The LC50 of caoping-1 against pink woodsorrel was 106. 67 mg/L on the 7th day after treatment, which showed high activity of removing weeds, and safety to lawn grass. The glyphosate had better effect against pink woodsorrel, but the growth of lawn grass were also inhibited to varying degrees at the concentrations used in the experiment.

Abstract:The present paper gives a brief review of Unaspis MacGillivray, provided with the key to the species of China.One species was described as new to science: Unaspis nanningensis sp. n.

Abstract:Hirschmanniella mucronata and H. Oryzae from rice (Oryza sativa) roots and rhizosphere soil were described as new records for Hongkong.

Abstract:The treatment of spraying cerium trichloride and rare earth nitrate on sugarcane with three concentrations (100, 300, 600 mg/L ) were done at middle tillering stage. The isozyme of peroxidase and esterase of leaf was assayed by means of polyacrylamide gel electrophoresis at the 3th day for the treatment of cerium trichloride and at the 20th day for the treatment of rare earth nitrate. The results showed that both types of rare earth had influences on foe isozyme level, but were different from each other. In the treatments of three concentrations, it was found that the effect of 300 mg/L was most distinct with more enzyme bands coloured deeply, 100mg/L secondly and 600 mg/L indistinct. On zymograms of esterase isozyme and peroxidase isozyme treated with cerium trichloride , the enzyme bands were increased or decreased in some zones.

Abstract:PVP was added to different media to prevent the tissue from brown-turning. The comparisions were made among the hormone on the planted number, variation rate, root number, fresh and dry weights and chlorophyll content. The result showed that mixture of KT and 6-BA with high concentration not only favored the shoot differentiation but also improved the quality of plantlets.

Abstract:After blocking Ca~(2 ) CaM messenger transduction by pretreating rhizosphere of rice seedling with LaCl3 or CPZ (chlorpromazine), survival rate, relative water content and relative biomass of rice seedlings subjected to drought , salt and chilling stresses decreased, at the same time membrane permeability increased. These results suggested that Ca2 . CaM messenger system was involved in controlling stress resistance of rice seedling, blocking messenger transduction, drought resistance, salt resistance and chilling resistance decreased.

Abstract:One species of the genus Periploca (Asclepiadaceae), P. caudatifolia P. T. Li et Z. K. Li, is described from Madagascar.

Abstract:Mycorrhizal associations of twenty plant species in four different plant communities of the Chebaling National Nature Reserve were investigated in the summer from 1995 to 1998. Except for two species (Dicranopteris linearis and Diospyros tsangii), eighteen species examined were associated with either vesicular-arbuscular mycorrhiza (VAM) or ectomycorrhiza (ECM). Four species of Fagaceae and Pinus massoniana were consistently associated with ECM while other thirteen species were associated with VAM. The fruiting bodies of ectomycorrhizal fungi were abundant and diverse in intact forest dominated by Fagaceae. Only a few species of macrofungal bodies were found in the pine dominated forest and secondary broad-leaved forest and none were seen in grassland during the study. VAM spore density was generally lower in the grassland than other community types. It is possibly due to degradation in floristic composition and soil fertility.

Abstract:The population of Phoebe bournei of Chebaling National Nature Reserve was studied by plot method. The preliminary result showed that the population of Phoebe bourbei of Chebaling presented an increasing pattern. Its seeds germinated well in situ; but the mortality rates of one-year-old seedlings were high. The major factors limiting the population of Phoebe bournei were discussed. Some conservation measures are also suggested.

Abstract:The efficacy of a novel vaccine, infectious bursal disease virus-antibody complex vaccine (IBDV-Ab), was compared with that of a commercial IBDV vaccine in Shiqiza broiler with maternal antibodies against IBDV. Seventy-five birds were divided into four groups and raised in isolation units. Birds of group 3 and 4 were vaccinated at 10 days with IBDV-Ab vaccine and commercial vaccine, respectively, whereas chickens of group 1 and 2 were not vaccinated with any vaccine. The antibodies against IBDV were measured by enzyme-linked immunosorbent assay (ELISA) before and after vaccinations. All the broilers of groups 2, 3, 4 were challenged with a virulent IBDV strain at 35 days of age. The mean ELISA titres (ET) of group 3 and 4 at 21 days of age were 738 and 946, respectively, and these at 31 days of age were 2 403 and 1 700. After challenge, mortality of groups 2, 3 and 4 were 50% 1 5% and 10% , respectively. The results showed that the efficacy of vaccination with IBDV-Ab vaccine was better than that with commercial vaccine. The data herein suggested that being mixed with antibody against IBDV increase the efficacy of IBDV live vaccine.

Abstract:This paper describes the design of a robot arm for gripping and throwing rice seedlings sprouted in cell-pan at an industrial nursery. Based on the bionics-analysis of hand gripping and throwing of rice seedlings in the field, three kinds of robot arm and two kinds of gripper for rice seedlings were designed. A 416-cell pan used for rice seeds sowing and suitable for robot-arm gripping and throwing of rice seedlings was designed.

Abstract:This paper deals with: Several methods of freezing-tolerance induction; Specific protein synthesis and gene expression and its relation to freezing tolerance; Species, cultivar and organ specificity of freezing induction and its relation to protein synthesis and gene expression.

Abstract:Ribozyme is a kind of RNA with self-catalytic activity which was found in 1980s. To block the expression of harmful genes, including self-mutation and heterogenous pathogens, in the human cell at level of nucleic acids, this is a very specific therapy with the least harm to human body. The natural ribozyme has the cis activity, but it can be engineered with trans activity. This is the base to design ribozyme with therapautic activity. In this paper, the authors mainly discussed the hammerhead and hairpin ribozymes, and the principles involved in application of ribozyme as therapautic agents were also given.

Abstract:小鸟花(Heliconia psittacorum)又名假天堂鸟,是一种需光强的高档切花植物,不足的光照强度是限制小鸟花切花产量的主要因子[1,2],有关、光照和光周期对小鸟花生长及切花产量的影响已有一些报道[3,4],但光照影响小鸟花细胞组织结构的研究很少,本试验旨在通过对遮荫与露地栽培条件下小鸟花生长、切花产量、叶片组织结构和细胞超微结构的观测及比较研究,从形态解剖学的角度探讨光照对产量影响的原因.

Abstract:切花的衰老与切花组织中各种植物激素的含量及它们之间的相互作用有密切的关系,其中乙烯和脱落酸在许多切花的衰老中起非常重要的作用.

Abstract:研究表明,植物在吸收和利用磷方面存在着可遗传的异,而且这些差异是由特定的生理生化基础决定的[1].