Pang Xiong-fei Liang guangwen You Minsheng Wu Weijian
1988(2).
Abstract:The application of state-space approach to population life system control, not only help to describe a system by components or subsystems, but also help to solve the difficulties of multi-input and multi-output technique in system analysis. So that, it may be used as an important method to study the insect population ecology. In this paper the network models are used to construct the state-space equation for insect population dynamics.
Wang Zhenzhong Lin Kung-hsun Faan Hwei-chung
1988(2).
Abstract:It was shewn by applying different models ( Logistic, Gompertz and Weibull) to data obtained by field disease investigation that Weibull model described the progress curves of Chinese-Small-Cabbage Mosaic ( mainly caused by Turnip Mosaic Virus and Cucumber Mosaic Virus ) the best, and the Logistic better than Gompertz model. Nonlinear method, Gauss-Newton algorithm and Marquardt' s algorithm, was proposed for the fitting of two-parameter equations of plant disease progression. A comparison was made of nonlinear and linear method by using 94 sets of plant disease progress data o f 18 disease systeme; results showed that the nonlinear method was better than the linear method in all casas.
1988(2).
Abstract:In this article the organization of the fruit market in Hong Kong had been described. The economic analysis were made in four aspects, viz. 1 . the pattern of demand and supply of fruits in Hong Kong;2. the origin of imported fruits: 3. the types of frpits imported; and 4. the prices of fruits imported. preliminary analysis showed that the fruits frcm inland China shared only a minor portion in Hong Kong market. Due to the relatively Low quality, prices of the Chinese fruits were relatively cheap; they are facing a serious challenge from foreign fruits. The reasons for this unfavorable situation were given. In conclusion" suggestions were made to increase the export of fruits.
Wang Runhua Li Zuqing Wang Kuochang Lu Yonggon
1988(2).
Abstract:以水稻白叶枯病病原细菌(Xanthomonas campestris PU.Oryzas)的41个菌株,对9个水稻品种作抗病性鉴定。利用Tai氏所提供的分析方法,估测和分析各供试品种及病原菌株遗传型稳定性参数。试验结果表明:抗原品种与病原菌株之间存在很显著的互作。根据平均病级及抗病性稳定性程度,把水稻品种划分为8个类型,还根据致病力的强弱及致病性的稳定性的程度,把病原菌株划分为6个类群。本文对水稻白叶枯病抗病性鉴定中的“标准鉴别品种”应具备的条件提出初步意见。还从供试菌株中筛选出一套具有稳定致病力的鉴别菌株。
1988(2).
Abstract:Accordiug to genetic divergence and systematic cluster analysis of quantitative characters in 32 slender high grain quality varieties of rice ( Oryza sativa L. subsp. hsien.Ting ) in South China region.the varieties were classified into 5 types. The genetic divergence of different types was greater then the similar tyte. It is showed that selection parents for hybridization in rice breeding for slender high grain quality may be conducted between different types, but one of parents has fit the object of breedieg, when it will be only impoved 1 to 2characters, other pareut may be also not selected the variety of greater genetic divergence.
Ning Zhengxiang Huang Chang-xian
1988(2).
Abstract:The culture of the nodal segments from juyetnile and mature shoots of Clausena lanstum (Lour) skeels grown in field was successfully established in vitro. The suitable medium was WPM + BA 1.0+KT 0.5+NAA 0.5 + GA3 0.25+ 4-5% sucrose. Surfaces of plant parts carry a wide range of microbial contamints, which were the main sourse of infection to plant in vitro.
1988(2).
Abstract:Observations on the evoked potential of the cerebral cortex ( CEP ) and the spinal cord surface ( SSP ) induced by electro-rtimulation of the tibial nerve under the influence of electro-acupuncture in 15 goats are reported in the present paper. Experiments results revealed that the inhibitory effect of the electro-acupuncture appeared both in the CEP and the SSP. It was also noted that while the former was completely inhibited the latter showed only slight inhibition. It indicates that the CEP as compare with the SSP is more facile to be inhibited under the influence of the electro-acupuncture.
1988(2).
Abstract:Testicular histological development in Japanese quail of different ages was stud -ied. Six stages in spermatogenesis were distinguished on the basis of microscopic examination. Primary spermatocytes were found in quails ages 11 days. Spermatids occured on day 36. The first mature spermatozoa were present in the seminiferous tubule on day 46. Some difference in structure and stainiing characteristic existed between the spermatids of the quail and those of other farm animal or chicken. The Leydig cells occured in quails before dayopersisted throughout spermatogenesis. This result was at variance with the changes seen in the Leydig cells of the domestic fowl. After 21 days of life, we could find a number of degenerative cells and some eosinophil bodies which consisted of several eosinocytes. Two, Three or even more nuclei were observed in the eosinophil bodies.
1988(2).
Abstract:Clinical and hematological studies on 1 to 5-day old susceptible chicks inoculated intravenously with Avian Myeloblastosis Virus ( AM V ) are reported here. The onset of disease was seen 2 to 6 weeks postinoculation, the sick birds exhibiting extreme anaemia, accompanied by diarrhea and the appearance in the blood of numerous mysloblasts showing typical morphology. The blood plasma contained AMV.
1988(2).
Abstract:橡胶树(Hevea brasiliensis)褐皮病的症状特点是割线上下皮层有明显的褐斑病灶,排胶减少或不排胶。病树树冠上还往往会发生枝条变扁、畸形、缩节、丛枝,顶部叶片变小成簇的丛枝病。有丛枝病的芽接树,90%会同时发生褐皮病,其余在1/2~1年也会发生褐皮病,两者关系密切。电镜检查,在无性系GT1及RRIM600病树树干韧皮部筛管细胞发现多形态类立克次氏体(RLO),菌体大小分别为100~2400nm和275~1395nm;在GT1根部的RLO为576~825nm;在IAN6645及PB28/59病树树冠上表现有丛枝病症状的病枝里为球形和椭圆形,大小为390~920nm;病树RLO壁厚约20nm。上述健康对照树均没有发现RLO。因而认为树冠的丛枝可能就是橡胶树褐皮病的一种症状。 七年(1979~1986)研究表明,橡胶褐皮病树经注射或环状刮皮涂保01、青霉素及四环素后,胶乳及干胶产量比对照树明显增产,病情减轻,其中以“保01”的效果最好,药剂有效持续期为3~6个月。药物处理对中、轻病树效果较好,对重病树效果较差。 根据上述试验结果,我们认为RLO是橡胶树褐皮病的病原。
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