Abstract:In the experiment,several photoperiod-temperature sensitive genie male sterile lines and some indica,japonica or javanica varieties (including wide compatibility varieties) were crossed to obtain 25 intersubspecificF1 hybrids(17 indica-japonica and 8 indica-javanica hybrids),15 intervarietal F1 hybrids.The feature andproblem in use of intersubspecies heterosis in south China region of two season rice were pointed out.The results indicated,Principal problem of intersubspecif ic F1 hybrid of two lines was lower setting percentage and grain-straw ratio.Indica-japonica hybrid was susceptible to environment condition.Filled graings per panicle and panicles per plant were the important factors determining grain yield per plant.Setting percentage was the key character affecting filled grains per panicle.The suggestions for increasing setting percentage and grain-straw ratio had been proposed.

Abstract:作者采用生物活性追踪法,报道黄杜鹃花杀虫活性成分的提取、分离和鉴定结果,三种对害虫具有较高活性的化合物——闹羊花索-Ⅲ、Grayanotoxin-Ⅲ和Kalmanol已被分离出来,其中以闹羊花素-Ⅱ为主要杀虫有效成分,在花中含量最高,达0.2％,另二种化合物的含量仅为0.04％。这三种化合物对马铃薯甲虫和草地夜蛾的拒食和毒杀作用强弱顺序为闹羊花素-Ⅱ> Grayanotoxin-Ⅲ=Kalmanol.闹羊花素-Ⅱ或花乙酸乙酯萃取物对马铃薯甲虫和草地夜蛾的盆栽药效试验表明,防治效果良好,此外,对杂拟谷盗成虫亦有很强的毒杀作用和控制种群的作用。

Abstract:Based on the average life table,by means of the population matrix model,the abort-term forecast of the population dynamics of brown rice planthopper,Nilaparvata bgugems(BPH) was studied in this paper.The BPH population was grouped in the life table,during the egg,1st-2nd instar of nymph,3rd-5th instar of nymph and adult stages.It was problem that the developmental rates in various stages were unequal.In this paper,the varias groups were subdivided into daily states to compose the state vectors and the transitional matrix is also expanded to square matrix correspondingly.The BPH numbers in daily stages would be outputted continuously fir 40 days (x (t1) to x (t4s)) by using the output mathematical model,when the state variables of the initial time (X (ts)) were inputted.The forecasting results from the output mathematical model may be realised in the similar conditons,if the rice variety resistance range to BPH and the other interference factors are not changed evidently.

Abstract:The control effects of the predators on the population of the brown planthopper,Nilaparvata bugens was studied in the light of rotation composite design of regression and the state-space method in this paper.The main predators in paddy field in Hailing Island in Guangdong province as the object population for constructing the equation of populations control index(IPC).It was emphasized that the state-space metod and IPC could be used to study the integrative control effcts of the predators on pest insects.

Abstract:The successive life table of paddy stem borer,Scir-pophaga incertulas (walker),on early rice in 1988-1990 were constructed in this paper,with the probability of effective eggs (=actual eggs/expected eggs),served as a linker of two generations By means of exclusion analysis method and exclusion index of population control (EIPC) from the data of the successive life tables,the probasbility of effective eggs of the 1st generation was an important factor affecting the population.In addition,the mortality of the larvae and pupae in overwintering generation also played an important role on the population trend.The overwintering adults laid the eggs on the rice seedings or on other places.But,the hatched larvae of this monophagous insect developed only on the growing rice.The egg period of 1st generation and the planting times of the early rice played an important role coordinately on the probability of effective eggs.It is a useful method for controlling paddy stem borer on early rice to regulate the coordination of the rice planting time with the egg period of 1st generation.The 1st-2nd generation of paddy stem borer developed in a relatively constant environment.By means of data in average successive life table,the effective egg density of the first generation may be used as the starting point to forecast the density of the 2nd generation of this insect

Abstract:A strain of CMV (CMV-T37) which was widely found and caused tomato mosaic in Guangdong province was used as on inoculum to infect the virus-free banana plants by mechanical juice inoculation and by aphid transmission artificially in the green-house as naturally by growing infected tomato or/and cucumber plants in the trial fields.The results of all experiments were positive with high percentage of infection and showed that the solanaceous and cucurbitous plants infected by CMV-T37 might serve as the primary and secondary sources of infection of the banana mosaic disease,besides the diseased banana plants (including sucker) itself in Guangdong Province.

Abstract:A new plant pathogen identified as Hendersomula psidii R.Liu et P.K.Chi n.sp.was described.The type spcimen is deposited in the Department of Plant Protection,South China Agricultural University,Guangzhou,China.

Abstract:Ulteastructural changes of chloroplasts and mitochondria in mesophyll cells of sugar cane leaves under water stress were described.The outer membranes of the chloroplasts were broken.Many osmiophilic globules were found and the disapppearance.of grana and disruption of lamellae were observed wighin the chloroplasts.The outer membranes of the mitochondria were also broken.The cristae disappeared ?and some lipid droplets in the cytoplasm were observed.The degree of organelles disruption was lighter in the variety Co331 than in the variety Yue Tang 57/423.

Abstract:Four types of explants of Panax (?) were used,in order to study induction of callus,differentiation of plantlets,hardening of regenerated plantlets and formation of roots.Experimental appproach to find a suitablepathway of differentiation,has been referred to the method for producing large numbers of plants.The results showed that explants sterilized with both HgCl2 and NaOCl had low contamination rate.Culturedon MS based nutrient medium,young inflorecencea were the best explants,which had highest frequency of callus formation and plant differentiation.In MS supplemented with 2,4-D medium,calli could directly initiate a large number of embryolds under dark condition and could initiate adventitious buds under lighting.Plant regeneration of embryoids and adventitious buds could be achieved by use of OA3 in the regeneration medium.Root formation was induced with MET.Complete plants were developed.Appeoximately 2 214 plants have been obtained.The plantlets were first successfully developed by in vetro method in 1989,From 1990 to 1991,a series of technique of obtaining high propagation were founded.

Abstract:硫氰酸化合物广泛地存在于十字花科作物中，一些研究指出它与这些作物呈现出甲状腺素活性和对某些虫害的发生有关。本研究测定了国内常见的五种十字花科蔬菜中SCN-的含量.同时对此分析方法的适宜条件进行了模索，提供了一种较为简便快速测定SCN-的分析方法。在0.5M HNO:介质中，过量的Fe~(3+)SCN-反应显色，反应混合物的入max为460 nm，测定范围:0～2.0ug/ml(KSCN)，相关系数r=0.9994，最低检出限:04ug/ml(KSCN)

Abstract:The systems engineering principles were used to identiy the natural and social envirinment in Taishan county with the help of the model of envirinment identification,and the dominant,restrictive and potential envirinment factors were got;the stages of forestry development and the characteristics of forest resources in Taishan county were analysed;furthermore,the forest economical ecosystem in this county was diagnosed by using the model of systems diagnosis,the problems,potentialities,ways,dominance and breaching point were got by opening up this actual system in time and space;finally,the guidelines for the total development planning of forestry in this county were put forward on the basis of the analysis of the above three parts,and the decision analysis on the total development planning of forestry in this county was studied by using the model of analytic hierarchy process,and the objectives,planning regions and measures of the total development planning of forestry were suggested.

Abstract:This paper gives a brief account of Dual-Number and Quaternion Algebra and its signilicanoe on ipatial mechanisms and robots design.As a specimen the author studied the displacement of the spatial RCPRC five-link mechanism,deduced the calculation formulae and obtained the numerical results.

Abstract:Contents of endogenous hormones in Litchi fruits (Litchi chinensis Sonn.Var.Hualzhi) were determined during fruit development The data showed that the contents of the cytokinind (CTK) and Indole-3-acetic acid (IAA) were higher during the early stages of fruit development.There were a peak of gibberellin4+7 rlevel and a peak of ethylene level at the second stage of fruit development.The fluctuations of these endogenous hormone levels were correlated respectively with growth ,development and drop of fruits.Treated fruiting panicles with CTK at the first stage or GA3 at the secod stage could increase the rate of fruit setting obviously.

Abstract:The flowers of atemoya are protogynous.Studies revealed that the anthers dehisced at 6-8pm.Hand-Pollination was very effective in increasing fruit act The way was to take the pollen direcyly from the flowers in anther dehiscence with a brush and then transfer it to other flowers without anther dehiscence.If the anther of the recipient remained in undehiscenceness on hand-pollination day the rate of fruit set world be 94.0% in threeweeks.However,if the anther dehisced a short time after hand pollination the rate of fruut set would be 23.9%,on the same level as the control,18.9%.This showed that stigma lost its receptivity completely shirtly before anther dehiscence.

Abstract:The disposition kinetics of sulfadimidine(SM2),isoniazid(INZ),bromsulphalein(BSP) and phenol-sulfonphthalein (PSP) in normal Swine (n=22,30~39 kg b.w.) were investigated,which was designed to compare with the pharmacokinetics of those drugs in infected Swine.The studies showed that the disposition of SM2 in Swine was characterized with medium distribution volume and low clearance,INZ with high distribution volume and high clearance ,and both BSF and FSP with low distribution volume and high clearance.Such distribution and elimination properties of the drugs determined their concentrations in plasma and half lives in the body,and depended on the elimination capacity of the liver and kidney and the protein-binding of the drugs in the plasma.

Abstract:In order to investigate how blood compositions are changed by contagious diseases,7 hybrid pigs were infected by inoculating each with 1.25 billion live Streptococcus suis Subcutaneously.Severe hematological changes could be observed at 5 and 10 days after inoculation,which was characterized by hemorrhagic anemia ,hypoproteinenvia and hyperleukocytosis,and accompanied by high erythrocyte sedimentation rate and incresed munber of blood platelets.Among lymphocytes,T-and living cells decreased,and B-and dead cells increased signifificantly,although there was no marked change in the proportion of lymphocytes to neutrophilic cells in the blood of infected animals.Intravenous injections of sulfadimidne +trimethoprim to infected animals continously for 6 days (twice a day) from the 9th day after infection ,were able to improve the hematological and immunological picture significantly and make the animals recover.The interactions among animals,bacteria and therapeutic agents are discussed.

Abstract:Investigation on the fluoride-resistance of silkworm,Bombyx mori,and estimation of the corelatlonship between the fluoride-resistance and the other economic characters had been conducted.These can provide the scientific basis for the breeding of anti-fluoride races.The resistance to the fluoride-poisoning is strengthened with the growth of silkworm larvae,that is,4th instar>3rd instar>2nd instar.The resistant ability of F1 hybrids of the strong fluoride-resistance crossing groups was in between that of the parents'.For the Fl of the weak fluoride-resistance crossing groups,their resistance expressed was higher than their parents'.The resistance of different varieties was significantly different due to the various concentrations of fluoride.The andi-fluoride and the anti-DNV characters wen in significant positive corelation.But there were no such corelation to the cocoon quality,and the content of Ca and Mg ions in the larvae blood.