节节麦×大麦杂种胚再生植株的细胞遗传学研究

以节节麦(2n=14)为母本和大麦(2n=14)进行杂交,两组合平均结实率为31 .11%。对31个幼胚进行愈伤组织诱导培养,其中2个形成全能性愈伤组织进而分化出再生杂种植株。细胞学观察表明,杂种胚再生植株均是染色体加倍的节节麦-大麦双二倍体(2n=28)或染色体再加倍的多倍体。节节麦-大麦双二倍体在减数分裂中期Ⅰ染色体配对平均构型为14.79Ⅰ+1.95Ⅱ+ 4.53Ⅱ′+0.01Ⅲ,表现为自交不育。杂种胚再生植株染色体数目再加倍的多倍体有少数产生了自交种子。 Abstract:Hybridizations between Aegilops tauschii(2n=14)and Hordeum vulgare(2n=14)were made using Ae.tauschii as female.The mean frequency of seed set was 31.11% in two cross combinations,13 hybrid embryos were cultured for inducing callus,of which 2 produced totipotent callus,and plants were regenerated from them.These plants were Ae.tauschii-H.vulgare amphidiploids with doubling chromosome number(2n=28)and octoploids with repeatedly doubling chromosome number(2n=50~56).The Ae.tauschii-H.vulgare amphidiploids were sterile and their average chromosome pairing at MI were 14.79I+1.95II+4.53II′+0.01III.Some octoploid(2n=56)plants produced seeds after selfing.     

Origin,dispersal, cultivation and variation of rice

There are two cultivated and twenty-one wild species of genus Oryza. O. sativa, the Asian cultivated rice is grown all over the world. The African cultivated rice, O. glaberrima is grown on a small scale in West Africa. The genus Oryza probably originated about 130 million years ago in Gondwanaland and different species got distributed into different continents with the breakup of Gondwanaland. The cultivated species originated from a common ancestor with AA genome. Perennial and annual ancestors of O. sativa are O. rufipogon and O. nivara and those of O. glaberrima are O. longistaminata/, O. breviligulata and O. glaberrima probably domesticated in Niger river delta. Varieties of O. sativa are classified into six groups on the basis of genetic affinity. Widely known indica rices correspond to group I and japonicas to group VI. The so called javanica rices also belong to group VI and are designated as tropical japonicas in contrast to temperate japonicas grown in temperate climate. Indica and japonica rices had a polyphyletic origin. Indicas were probably domesticated in the foothills of Himalayas in Eastern India and japonicas somewhere in South China. The indica rices dispersed throughout the tropics and subtropics from India. The japonica rices moved northward from South China and became the temperate ecotype. They also moved southward to Southeast Asia and from there to West Africa and Brazil and became tropical ecotype. Rice is now grown between 55°N and 36°S latitudes. It is grown under diverse growing conditions such as irrigated, rainfed lowland, rainfed upland and floodprone ecosystems. Human selection and adaptation to diverse environments has resulted in numerous cultivars. It is estimated that about 120000 varieties of rice exist in the world. After the establishment of International Rice Research Institute in 1960, rice varietal improvement was intensified and high yielding varieties were developed. These varieties are now planted to 70% of world's riceland. Rice production doubled between 1966 and 1990 due to large scale adoption of these improved varieties. Rice production must increase by 60% by 2025 to feed the additional rice consumers. New tools of molecular and cellular biology such as anther culture, molecular marker aided selection and genetic engineering will play increasing role in rice improvement.     

籼稻品种窄叶青8号抗稻瘟病基因分析

籼稻品种窄叶青８号是我国北方稻区水稻育种上重要的稻瘟病抗源之一。本文利用我国北方稻区的代表菌系中１０－８－１４和日本的代表菌系研５４－０４,对窄叶青８号与感病品种京系１７号和丽江新团黑谷的杂交Ｆ１Ｆ２、ＤＨ和Ｂ１Ｆ１群体进行抗病性鉴定,根据抗病性的分离,确认窄叶青８号的抗性由１对显性主效基因,即朱立煌等报道的Ｐｉ－ｚｈ基因控制。利用系研５４－０４接种窄叶青８号与９个具有已知抗病基因的鉴别品种杂交的Ｆ２群体,各群体都表现二基因的独立遗传,证明Ｐｉ－ｚｈ基因与Ｐｉ－ｉ、Ｐｉ－ｋｍ、Ｐｉ－ｚ、Ｐｉ－ｔａ、Ｐｉ－ｔａｚ、Ｐｉ－ｚｔ、Ｐｉ－ｋｐ、Ｐｉ－ｂ和Ｐｉ－ｔ等９个已知抗病基因间存在非等位关系,是新的抗稻瘟病基因。     

Construction of Oryza sativa genome contigs by fingerprint strategy

We described the construction of BAC contigs of the genome of a indica variety of Oryza sativa.Guang Lu Ai 4. An entire representative(Sixfold coverage of rice chromosomes)and genetically stable BAC library of rice genome constructed in this lab has been systematically analysed by restriction enzyme fragmentation and polyacrylamide gel electrophoresis.And all the images thus obtained were subject to image-processing,which consisted of preliminary location of bands,cooperative tracking of lanes by correlation of adjacent bads.a precise densitometric pass,alignment at the marker bands with the standard,optional interactive editing,and normalization of the accepted bands.The contigs were generated based on the Computer Software specially designed for genome mapping.The number of contigs with 600 kb in length on average was 464.of contigs with 1000kb in length on average was 107; of contigs with 1500 kb in length on average was Construction of Oryza Sativa genome contigs.23.Therefor,all the contigs we have obtained ampunted up to 420 megabases in length.Considering the size of rice genome(430 megabased),the contigs generated in this lab have covered nearly 98% of the rice genome.We are now in the process of mapping the contigs to chromosomes.     

印楝素、印楝和苦楝种子抽提物在盆栽植物中的内吸作用(英文)

本文报道具有拒食活性和生长发育调节作用的植物性杀虫剂印楝素、印楝和苦楝种子抽提物的内吸防治几种农业害虫的试验研究。结果表明：内吸施用印楝素或印楝种子粗提物（1mg和2．5mg／盆）能明显降低烟草天蛾幼虫的正常生长和干扰马铃薯甲虫的生长发育;用≥25mg／盆的印楝素和印楝种子租提物能明显控制麦二叉蚜的种群繁殖。而苦楝种子甲醇抽提物对上述三种害虫的内吸控制种群繁殖作用不明显。     

Bioefficacy and mode of action of rocaglamide from Aglaia elaeagnoidea (syn. A. roxburghiana) against gram pod borer,Helicoverpa armigera (Hübner)

Abstract: Rocaglamide, a highly substituted benzofuran, was isolated and identified as the main biologically active component in Aglaia elaeagnoidea (syn. A. roxburghiana) for gram pod borer Helicoverpa armigera (Hübner). Addition of rocaglamide to an artificial diet retarded the growth of neonate larvae in a dose‐dependent manner with EC₅₀ values of 0.76 p.p.m. These values compared favourably with azadirachtin (EC₅₀ = 0.23 p.p.m.). However, azadirachtin was apparently more potent than rocaglamide in inducing growth inhibition via oral administration to these first stadium larvae. The candidate compound was found to have LD₅₀ and LD₉₅ values of 0.40 and 1.02 μg per larva, respectively, in topical application against third instar larvae 96 h post‐treatment. However, these values for azadirachtin were 8.16 and 25.8 μg per larva for the same period. This shows that azadirachtin was less effective against third instar H. armigera larvae in inducing acute toxicity via topical treatment in comparison with rocaglamide. However, severe morphological larval deformities were observed in such azadirachtin‐treated larvae during the process of ecdysis. The cytotoxic nature of rocaglamide was established by evaluating dietary utilization and the results did not implicate any antifeedant effect but the toxicity‐mediated effect due to reduced efficiency of conversion of ingested food. It was obvious that feeding deterrence is not the primary mode of action but a centrally mediated effect, which could be due to the induced cytotoxicity at non‐specific cellular levels.     

Effects of hot water treatments and storage temperatures on the ripening and the use of electrical impedance as an index for assessing post-harvest changes in mango fruits

The effects of hot water treatment and storage temperature (4°C, 13°C or 22°C) on the quality and impedance of outer and inner mesocarp of mango were assessed in two experiments during storage, impedance being a potential non‐destructive measure of tissue damage following heat treatment. Fruits were subjected to equivalent heat units at 36.5°C for 60 min plus 46.5°C for 43 min or 46.5°C for 90 min by hot water treatments (hwt) on the assumption of cumulative heat effects and a base temperature of 12–13°C. Fruit reflectance decreased whereas chroma and hue angle increased over storage time and also with increase in storage temperature. The yellow colour increased with a rise in storage temperature in hot water treated mangoes. Soluble solids content of mangoes held at 22°C was highest at 5 days of storage but decreased subsequently over storage time. Impedance of all fruits decreased with increase in frequency, storage temperature and time in store. The impedance of hwt mangoes was lower than that of non‐hwt fruits 8 h after immersion, but recovered almost to control levels on day 5 at 4°C or 13°C, but decreased gradually after 5 days at 13°C. Impedance of all mangoes stored at 22°C decreased continuously during storage. Impedance was higher in the inner mesocarp than outer pulp. Impedance of hwt fruits was poorly correlated with soluble solid content and chroma but well correlated with reflectance of fruit pulp at 22°C. Changes in impedance of mangoes are discussed in relation to physiological and biochemical changes that occur during heat treatment and storage.     

几种影响籼稻成熟胚愈伤组织诱导及再生的因素

建立了适合5个籼稻品种成熟胚籼稻遗传转化的高效植株再生体系.N6基本培养基有利于籼稻愈伤组织的诱导和继代培养;N6大量元素和MS微量元素有利于愈伤组织的分化.降低分化培养基中蔗糖含量,加入适量山梨醇、Cu2 、Ag 和玉米素(2T)均可明显提高水稻愈伤组织的再生植株频率,5个品种分化频率均达到75%以上.     

了哥王茎皮化学成分研究

从瑞香科荛花属植物了哥王(Wikstroemia indica)的茎皮中分离鉴定出5种化合物,其结构分别为西瑞香素(1)、芫花素(2)、槲皮素(3)、杨梅素(4)、山奈酚(5)。化合物3、4、5为首次从该植物中分离得到。     

不同环境下籼稻糙米重的发育遗传研究

采用包括遗传主效应和基因型与环境互作效应的数量性状发育遗传模型和统计分析方法 ,分析了籼稻(OryzasativaL .)稻米 4个发育时期糙米重的两年资料。结果表明 ,除了三倍体胚乳和二倍体母体植株基因的加性和显性主效应以及细胞质主效应可以控制不同稻米发育时期的糙米重量外 ,基因型与环境互作效应也可明显影响不同发育时期糙米重量。基因加性主效应和加性×环境互作效应在整个稻米灌浆过程中起着主要作用 ,对糙米重的选择可以取得良好的改良效果。条件方差分量分析结果表明 ,胚乳和母体植株中控制糙米重表现的基因在多数稻米发育时期均有新的表达 ,且以稻米发育早期为主 ,开花后第 1～ 7天是控制糙米重的基因表达最为活跃的时期 ,其次为开花后第 8～ 14天。一些基因只在个别发育时期间断表达 ,这在净细胞质主效应和净细胞质×环境互作效应以及净显性主效应上表现得尤为明显。稻米不同发育时期的遗传效应预测值表明 ,V2 0和作 5等亲本可以明显提高后代的糙米重量。