Structural observations during androgenic microspore culture of the 4c1 genotype of Zea mays L.

Summary The capacity of the maize genotype 4c1 to regenerate microcalli and embryos from cultured microspores has been examined by comparing various cold pretreatments and culture media, using microspores and pollen at different stages of development. Viability of cultured cells was tested with FDA and their development was traced with light and fluorescence microscopy using DAPI as a nuclear dye.It was found that a pre-incubation of dissected flowers floating in a liquid nutrient medium at 8°C during 10–14 days was most successful for the induction of cell division. Among the developmental stages tested only the microspores appeared to regenerate. Subculture at 25°C in the same liquid medium, supplemented with 0.1 mg/l TIBA, gave highest rates of microspore division, i.e. up to 70% at 4 to 6 days of culture.All pathways described earlier for maize androgenic embryogenesis were observed within the 4c1 genotype. Symmetric divisions occurred in cultured microspores but most frequently asymmetric divisions lead to the formation of microcalli within 12 days of culture. In at least 60% of all dividing microspores cells were derived from the generative nucleus. Microcalli further developed either into loose or compact calli. Compact calli formed embryo-like structures.Abbreviations DAPI 4,6-diamidino-2-phenylindole - Dicamba 3,6-dichloro-2-methoxy benzoic acid - 2,4D 2,4 dichlorophenoxyacetic acid - FDA fluorescein diacetate - PAA phenylacetic acid - TIBA 2,3,5-triiodobenzoic acid - YP medium Yu-Pei basal salt medium     

山羊卵泡卵母细胞体外成熟的研究

为了建立针对山羊卵母细胞的理想体外成熟培养体系,对山羊卵泡卵母细胞的采集方法,FSH和LH对山羊卵泡卵母细胞体外成熟的作用,及培养时间对卵母细胞体外成熟的影响进行了研究。结果表明:采用切割法平均每枚卵巢采集到的A,B级卵母细胞的数量明显多于抽吸法;采用TCM199添加体积分数为10?S,1~2 mg/L 17β_E2,10 mmol/L Hepes,0.12 mg/mL丙酮酸钠,0.1 mg/mL链霉素和0.125 mg/mL青霉素,10 mg/L FSH及20~50 mg/L LH的培养体系,有利于山羊卵母细胞的体外成熟,并放出第一极体。山羊卵母细胞体外成熟培养20,22,24 h,成熟率显著高于培养18,26,30 h(P<0.05)。     

土壤不同营养状况与强筋小麦产量和品质的影响

试验研究了土壤不同营养状况对强筋小麦子粒产量和品质的影响。结果表明：在10个处理中,土壤长期施用N,P,K等主要营养元素且配合比为1：1：1(N120．0kg／hm^2,P2O5 120．0kg／hm^2,K2O 120．0kg／hm^2)时产量最高为5433．0kg／hm^2,不施肥(ck)产量最低为1260．0kg／hm^2;蛋白质含量以单施N素(N120．0kg／hm^2)时最高达17．00％,N、P元素配合比为1：1(N60．0kg／hm^2,P20560．0kg／hm^2)时蛋白质含量最低为10．53％;蛋白质产量以N、P配合比为3：1(N180．0kg／hm^2,P20560．0kg／hm^2)时最高为696．0kg／hm^2,以单施P素蛋白质产量最低为156．0kg／hm^2。     

化学药剂诱导植物抗病性研究进展

诱导抗病性（Induced resistance）是指利用生物或物理、化学因子处理植物,改变植物对病原的反应,从而使其获得局部或系统的抗性。本文综述了近年来水杨酸、寡糖、聚糖及BTH等几种主要化学诱导剂在诱导植物抗病性中的应用。     

Practical Method for Dynamical Analysis to the Interlayer Seismic Isolation Masonry Building with Frame Structure in the First Storey

Masonry buildings with R/C frame- shear wall in the bottom storey have been widely used in city construction, which include two kinds of lateral force resistant system. However, the seismic behavior of the building is poor. Based on the characteristics that the rigidity of the upper masonry structure is much bigger than the rigidity of laminated rubber bearings and frame structure. It can be referred to as system having a two degree of freedom. The dynamic behavior of this building is analyzed, the isolated vibration mode controls the response of system. The authors give apractical method for dynamical analysis to masonry building with frame structure in the first storey with laminated rubber bearings between the first and second storey , which submits efficient path to found applicable design means and to generalize interlayer seismic isolation structure.     

Initial Expenmen Report on Hogh-yield Cultivation of Straw Mushrooms

比较草菇栽培料三种配方的生产效益，评价了五个主栽草菇品种的生产效益，结果表明:（1） V979 、V65、VP53、V23、V02五个品种的生物转化率分别为39.8%、38.5%、35.7%、30.5%、25.9%；（2） V979、V965耐低温，可在低温（15~25℃）下正常栽培；（3）原料配比：玉米秆 90%＋5%碎麦秸＋5%草木灰，对五种草菇均有增产效果，且原料来源广、成本低。     

MEASURING PROBABILITY OF SKY BRIGHTNESS IN CLASSIFICATION BY THE AVERAGE INSOLATION

According to the daily change law from curves for percentage insolation,this paper presents a new formula of the average insolation in the zones where the insolation is more than 70%. By means of the hourly observing data during two years for solar direct ratiation, cloudage and sunshine condition in seven zones different lighting climate,considering the vaper pressure and the altitude present the function of percentage insolation and the probability of four sky brightness classification,this formula has a certain precision to be proved by observation.     

苹果斑点落叶病研究

对北京地区苹果斑点落叶病研究得出,病原菌Alternaria mali Roberts强毒菌系是苹果斑点落叶病严重发生的主要原因.各果园病原菌强毒菌系发生率和致病性有差异.室内毒力测定和田间药剂防治试验结果表明,50%扑海因、70%代森锰锌、1.5%多抗霉素和10%宝丽安均有很好的抑菌效果.多抗霉素和宝丽安加入1%硼酸可以显著提高药效,并且硼酸本身对菌落生长有一定抑制作用.提出“重点保护春梢叶片,兼顾秋梢叶片”的防病原则.     

稻麦“双套”轻型简化栽培技术的研究及应用(Ⅰ) ——淮北地区稻棵套播麦的生育特点及栽培对策

系统论述了淮北地区稻棵套播麦播期提前，利于早发壮苗；群体大，高峰苗提前，利于足穗形成；幼苗发育进程提前，利于大穗形成的生育特点，及限制穗、粒、重三因素协调发展相关影响机理，提出了选用抗病品种、适期适量播种、“少食多餐”的平衡施肥方式、冬前保持地表土壤良好环境等配套轻型简化栽培技术，在生产实践中应用，取得了较好的经济效益和社会效益。     

基因组原位杂交技术在植物研究中的应用

基因组原位杂交是以亲本之一的总基因组DNA做探针,另一亲本的基因组DNA做封阻,在荧光原位杂交技术的基础上发展起来的一种染色体/染色质检测技术。在其发展的十几年里,已在植物的基因组研究中发挥了重要的作用。应用这一技术可对多倍体中基因组之间的亲缘关系、基因组组成及起源进行研究;对杂交种中染色体组的组成进行分析;对代换系、附加系和易位系进行有效的鉴定,并对其中的外源染色体或染色体片段的来源、大小、数目及发生位点进行检测和定位。此外,利用基因组原位杂交技术还有助于确定物种间的同源性;研究杂交种中来源不同的染色质在核中的分布;探索B染色体的起源、染色体间的配对、重组、交换等现象。随着基因组荧光原位杂交技术体系的不断发展、完善和改进,其应用范围不断拓展,在植物基因组研究领域中发挥了越来越重要的作用。