Abstract:以Ｗ６１５４Ｓ、Ｎ１２Ｓ、Ｎ１５Ｓ、Ｎ２１Ｓ、Ｎ３０Ｓ５个不育系为材料，于８月下旬及１０月上旬进行了开花习性的观察，结果表明：１．穗开花所需时间一般５～７ｄ，可育比不育短。一穗的盛花期可育时都分布在前期，不育时则因不育系不同差异较大。２．不育系的日开花动态受育性和环境的影响，主要表现在开花的高峰时段、峰值、花时集散及日开花朵数等方面。３．不育系的开颖角度和柱头外露率有的受育性和环境影响明显，有的不明显，有的只受育性影响。４．各不育系的开颖时间受环境影响差异很大，在同一环境里不育系都表现不育比可育开颖时间长。

Abstract:Eucalyptus citriodor Hook.is an important tree spedes of plantation in South China.The allelo pathic effects of aqucous extract of bark,leaf, root exudates and leaf volatiles on the germination and seedling growth of radish were studled.The results indicated that there are allelochemicals existed in aqueous extract of bark,leaf,root exudates and volatiles.Different sensitivity to inhibitions were existed in 9 acceptor plants.The inhibitor from aqueous extracts which has reversible effect to other plants were not easy to stay insoi.Volatiles inhibitions were easy accumulated in soil,its'inhibitory effects is inreversible.The inhibitory effects were significantly negatively correlated with the monthly rainfall in a year.

Abstract:Effects of three types of tester in maize which evaluated general combining ability(GCA) of the testing-iine were strdied comparatively.The results indicated that aester classes were an inportant reference inder for screeing superiou tester when GCA of yield was tesed.The syn-thetic variety was tested.The synthetic variety was a sort of good teser and generally could be used alone as tester.Superior tester could be obtained from the serious choice of interlinear hybrid and inbreed.Generally,the esrious chice for tester wasn't necessary when the GCA of the agricultural characters was tested.

Abstract:This study dealt with the effects of using four kinds of fertilizer application at the same effective fertility level under the normal late rice field management to pad- dy-fields in Guangzhou area on methane emission flux.The result showed that methane emitted significantly in the early growth phase of late rice in paddy-fields,in paddy-fields water immersion was a necessary condition for methane emission,no significant methane emitted in the dry-wet management period;methane emission flux in fields with organic manure applied was higher than that in fields treated with chemical fertilizers;higher soil temperature facilitated methane emission.

Abstract:Genetic diversity in Xuwen and Hainan yellow cattle and Holstein cows based on protein polymorphisms was studied with starch electrophoresis in this experiment.Among 40 gene loci of 36 blood proteins(enzymes),the same thirteen polymorphic loci in both Xuwen and Hainan yellow cattle and eleven polymorphic loci in Holstein were found.The percentages ofpolymomhic loic in Xuwen and Hainan yellow cattle both were 0.325,averageheterozygosity was 0.141 in Xuwen yellow cattle and 0.132 in Hainan yellow cattle,and the percentage of polymorphic loci and the average heterozygosity in Holsteinwere 0. 275 and 0.099 respectively. The results showed that genetic diversity was rich inXuwen,Hainan yellow cattle and Holstein cows and that both pereentages ofpolymorphic loci and average heterozygosity decreased as the cattle were being bred. The results also supported the conclusion that Xuwen and Hainan yellow cattle shouldbe one breed named Leiqiong yellow cattle.

Abstract:用碳化二亚胺作为交联剂将荚膜多糖与载体蛋白质交联后加入蜂胶佐剂制成疫苗免疫鸡只。７周龄同源菌株攻毒结果表明，荚膜多糖－破伤风类毒素苗组鸡有很好的保护效果且试验重复性好；在免疫后３个月的同源攻毒保护指数也达１３／２０以上。但对异源菌株的攻毒没有明显保护效果。该研究采用微量法间接血凝试验检测了免疫鸡抗体水平。

Abstract:Day-old SPF leghorn chicks were divided into four groups and raised separately in isolators.Group 1 chicks were inoculated s.c,with 0.2 mL M D vaeeine and 0.5 mL thymus extract in .the neck,group 2 chicks were inoculated with 0.2 mL MD vaccine(immunized control)only,group 3 and 4 chicks were not injected with any vaccine or other substanee.Group l to 3 birds were challenged with the virulent BJMDV-1 strain on day 13. Death occurred on day 17 and 24 post-infection for groups 3 and 2 birds respectively.For the groups that reeeived thymus extract,death occurred on 28 days P.I.,No death occurred in group 4.Group 1 showed 40% protection rate against MDV whereas the protection rate in group 2 was only 15.0% In addition,the group that reeeived immunengancement, had higher T lymphocyte level in the peripheral blood than group 2.Results of this experiment indicated that the thymus extract had the potential for improving immunizaton against MD.

Abstract:Based on experiments of biochenllcal changes in peanut plants(Arach is hypogaes)before and after rust(Puccinia arachidis)infection,the relationships between multiple biochemical com- pounds and rust resistance was analyho by using quantitative correlation method.Aller rust infection,changes of inducing sugars in peanut plants are highbcorrelated to disease resist-ance.Some free amino aclds,such as serine,leucine.methionine,isoleucine and arginine,are correlated to rust asistance at certain periods after infhoon.In healthy peanut plants,the ac- tivity of polyphenol oxidase,the amounts of threonine,serine,isoleucine and phenylalanine were highly correlated to disease resistance.

Abstract:显微观察表明，青枯病菌在番茄抗病试验材料与感病试验材料植株根内的扩展差异显著；青枯病菌可存在于感病试验材料皮层薄壁细胞间隙，瓦解细胞壁，形成溶生腔。在抗病试验材料维管组织中青枯病菌则被细胞壁所吸附；抗病试验材料的导管分子比感病试验材料短。

Abstract:首次报道了苦丁茶枯梢病。依病菌的培养性状、形态学特征和寄主专化性，该菌拟为一新的专化型──砖红镰刀菌冬青专化型（ＦｕｓａｒｉｕｍｌａｔｅｒｉｔｉｕｍＮｅｅｓｅｍｅｎｄＳｎｙｄ．ｅｔＨａｎｓ．ｆ．ｓｐ．ｉｌｉｃｉｃｏｌｌａＺ．Ｄ．ＪｉａｎｇｅｔＰ．Ｋ．Ｃｈｉｆ．ｓｐ．ｎｏｖ）。此专化型主要为害苦丁茶，刺伤接种可侵染鸡冠花。

Abstract:six new diseases of Iongan(Dimocarpus longan Lour.)were reported in this paper,theywere:leaf blight caused by Pedalotlopsis pauciseta(Sacc)Y.X. Chen,leaf spot by Ascochytalongan C.F.Zhnag et P,K. Chi,sp. nov.,grey leaf blight by Phomopsis guiyuan C.F.Zhang ct P.K,Chi,sp. nov.,brown leaf spot by Marssonina euphoriae C.F. Zhang et P.K,Chi,sp.nov.,and leaf spots caused by Leptosphaeria longan C.F. Zhang et P.K.Chi,sp.nov,or by Lephaeria guiyuan C.F, Zhang et P,K,Chi,sp. nov,The latter5 species were proved to be new in science. Description in Latin was given for newspecies.The type specimens are deposited in the Fungal Collection of South ChinaAgr.University.

Abstract:Psidium stem canker disease was serious yearly in the orchards of guava in the suburban dis-tricts of Guangzhou since 1988.It was proved as a fungous disease and the causal organismwas Botryosphaeria rhodina(Cke.)v.Arx,anamoph:Botryodiplodia theobromae Pat.Thefungus caused stem canker and longitudinal crack on trunks and twigs,and caused fruitsrotted.Both telemorph and anamorph of the pathogen could produee on the diseasedtrunks,twigs and fruits.According to the investigation in 1994,the pereent age ofdiseased trees grown above 4 years-old was over 70%,and many died in those of 6years-old.The test also showed that the fungus did not infect the trunk of Litchi,Mango,Longan,Orange,Chinese wampee,Papaya and Sapodilla and did not infect thecorm of Taro,but could cause fruit-rotted in tropical and subtropical fruit crops.

Abstract:Paratrichodorus minor,P,renifer and P.allius were described as new records for HongKong.P.renifer and P.allius have not been reported yet in the mainland of China.

Abstract:渗透胁迫下郑引一号（干旱敏感品种）幼苗硝酸还原酶（ＮＲ）活性下降的速率比陕合六号（抗旱品种）的快。小麦幼苗中含有ＮＲ钝化蛋白部分Ⅰ和部分Ⅱ，其中部分Ⅱ对ＮＲ的钝化活性大于部分Ⅰ；随着渗透胁迫的加剧，陕合六号与郑引一号的ＮＲ钝化蛋白部分Ⅰ的钝化活性减小百分率相近，郑引一号的ＮＲ钝化蛋白部分Ⅱ的钝化活性上升百分速率则快于陕合六号的，因而，在渗透胁迫下，郑引一号的总ＮＲ钝化蛋白活性比陕合六号的高。

Abstract:Physiological effects of PP333 on Calcelaria crenatiflora were studled. It was found thatPP333 strongly suppressed growth and increaesd the activities of peroxidase and IAA oxidaseand the higher the PP333 concentration,he stronger the effects,PP333 iIcrased the chlorophyllcontent and decreased the soluble protein content in the leaves;t was suggested that PP333inhibited growth by increasing the activities of Peroxidase and IAA oxidase,esulting in low-ering of endogenous IAA level.

Abstract:从豌豆种子提纯了超氧化物歧化酶（ＳＯＤ），纯酶比活性为７８４４×１０３Ｕ／ｇ。该酶受ＫＣＮ和Ｈ２ｐ２的强烈抑制，不受乙醇一氯仿混合液影响，说明为Ｃｕ、Ｚｎ－ＳＯＤ。酶分子量和亚基分子量分别为３２１００×和１４４００，表明该酶是由两个相同亚基组成。该酶在７０℃以下和ｐＨ５．０～１１．０范围内较稳定，紫外区最大吸收波长为２５９ｎｍ。

Abstract:The effect of long -term blue ligh on the photosynthesis of rice(oryza sativ a L.)seedlingswas studied.Compared to white light tieatment,the blue light treatment induced lowerphotosynthetic rate,photophosphorylation rate of chloroplasts and chlorophyll con-tent,and higher activities of RuBPCase,RuBPO and glycolate oxidase.It is suggestedthat augmented photorespiration in the blue light treatment may be one of the rea-sons for decreased photosynthetic rate.

Abstract:采用６０Ｃｏγ射线在０．４８、０．９５、１．４０ｋＧｙ剂量水平处理带螨的普洱茶研究其杀螨效果。结果表明杀螨的适宜剂量为０．５～１．０ｋＧｙ，辐照杀螨彻底，只要不再接触螨源就不存在孳生螨类的可能性。品质分析表明在这个剂量范围处理的普洱茶对其主要成分（水分、维生素Ｃ、氨基酸总量、茶多酚、咖啡碱）无不利影响。感观评价也表明经辐照处理的茶叶在外观色泽、香气、汤色、滋味及叶底方面与对照相比，均无明显差异。

Abstract:In this paper,the basic characters of the resourees of rare and endangered plants inGuangdong province and the causes of their endangerment are reported.The resoureesof rare and endangered plants in Guangdong possess the features of richness incomposition,complexity of flora,antiquity of origin,abundance of endemic ele-ments,diversity of usage,but of limited distribution.Some proposals for protecting theresourees of these plants are presented based on analysis of the causes ofendangerment.

Abstract:The resultS of the investigations on the wild woody plant resoruces of Guangdong arereported in this paper.There are 142 families, 666 genera and 3 212 species of wildwoody plants in Guangdong,making up 50.9%,41.9% and 51.2% of the total fami-lies,genera and species of the vascular plants in this provinee,The predominantfamilies and genera having woody species are analysed briefly and 39 species new toGuangdong are reported in this paper.

Abstract:Alpinia oxyphylla contams many constituents such as polyphenols,amino acids,Mn,Ca,Petc.which are useful for health care purpose. Results of toxicological tests indicated that theAlpinia oxyphylla is a safe health food.

Abstract:The molecular biotechnology has been developed rapidly and applied widely in all kinds offield in biofogy. It was generalized in this paper that some molecular biotechnology was of-ten used in the identificatoin of plant nematode spedes by nematology researchers at homeand abroad. The vista of the technological application in the field was prospected in the pa- per,.