用RAPD标记评价百合品种间遗传关系

本文从１３个百合品种种１野生种中分别提取了总ＤＮＡ，进行ＰＣＲ－ＲＡＰＤ分析，每个品种都得到了各自独特的带谱，通过对这些带谱的分析及数据的处理，并用计算机计算出百合品种间的遗传关系。结果表明，ＲＡＰＤ技术能用以鉴定百合品种间的遗传关系并推测其亲缘关系，本文对实验中遇到的一些问题进行了讨论。     

静电处理提高紫穗槐种子活力和苗木生长的研究

经过静电处理的紫穗槐种子活力指标:电导率、呼吸强度、活力指数、脱氢酶活性及ATP含量分别为对照的91.7,112.7,129.7,128.7,107.5％;苗高、地径、合格苗产量、单株生物量分别比对照提高14.1,17.8,18.4,4.81％。     

桃10～4500 MHz间的介电特性与内部品质关系分析

以不同成熟度的银风桃为对象,利用同轴探头技术测量了25℃下10~4500MHz间桃肉和桃汁的介电参数,并测量了桃肉的含水率、桃汁的可溶性固形物含量、pH值和电导率,分析了介电特性和内部品质间的关系.结果表明,桃肉和桃汁的相对介电常数皆随着频率的增大单调减小,而介质损耗因数呈现"V"型的变化趋势.离子的导电性和偶极子的极化分别是引起低频和高频下介电损耗的主要原因.桃肉和桃汁的介电参数与可溶性固形物含量、pH值以及含水率间没有明显的线性关系.     

335份旱稻核心样品的构建

通过方差分析和多重比较,评价了36种预选核心样品的遗传多样性,筛选出最适于本研究的核心样品构建方法,即25％总体取样量一多样性取样比例一组内聚类取样。并依据此方案构建了总数为84的旱稻核心样品。经2a重复实验,从多样性指数、质量性状、数量性状和群体结构四个方面所选核心样品的代表性进行评价和补充,最终形成总数为86的旱稻核心样品,该核心样品很好地代表了原始群体的质量性状及数量性状变异。为进一步将旱稻资源应用于水稻抗性改良和抗早稻育种打下良好的基础。     

旱稻引进种质的类缘关系与农艺特征分析

以5份水稻籼粳种质作对照，对15份引进早稻种质的类缘关系进行分析。结果表明，2份早稻种质属于籼稻，5份偏籼，4份偏粳，4份粳稻。对这些早稻种质的主要农艺特征进行了测验；并对其产量构成因子相关性作了分析。单株产量与7个穗部数量性状的相关性分析表明：单株产量与穗总粒数、结实率和穗数相关极显。与穗长相关显；早稻陆引46、IRAT l04、巴西陆稻、早稻297等4份引进种质综合农艺性状较好，单株产量较高，值得进一步种植观察。     

咖啡的生物全息现象及其遗传势的研究

根据全息生物学的理论,研究了咖啡树枝条不同部位叶片的面积、座果数量和光合速率等性状的差异。结果表明,这些性状均存在中部优势,体现了生物全息相关性。咖啡树枝条中部区段存在较强的遗传势,选取枝条中部咖啡豆(或芽条)培育种苗,可能有利于提高咖啡的产量与品质。     

海南山栏稻遗传基础的研究Ⅰ．核仁动态与核仁组织者数目的变化

研究海南山栏稻１６个品种花粉母细胞减数分裂前期１的核仁与核仁组织者的数目及动态，并与水稻和水旱稻杂种Ｆ１作比较，发现山栏稻近半数品种具有３对核仁组织者，比水稻多出１－２对，而且在第一次减数分裂中，核仁消失的时期比水稻晚。结果表明，海南山栏稻的遗传基础在一定程度上发生了变化。     

多层层叠式家禽饲养成套自动化设备的应用

多层层叠式家禽饲养成套自动化设备,在国际及国内健康养殖上已广泛使用,欧美、日本等发达国家早已使用．在国内上世纪九十年代初已开始使用,本世纪初大型养殖场也陆续使用,而且使用效果极佳．尤其现在对食品安全、生态环保、土地资源、禽病疫情等的要求越来越严格,越来越高的条件下．多层层叠式家禽饲养设备是规模化、集约化、自动化饲养的首选设备。它具有以下特点：     

Characterization of the burrow system of the earthworms Lumbricus terrestris and Aporrectodea giardi using X-ray computed tomography and image analysis

 The burrow systems of two earthworm species (Lumbricus terrestris and Aporrectodea giardi) were studied in artificially packed soil columns placed in controlled conditions in the laboratory. At the end of the incubation, which lasted 246 days, the burrow systems were characterized on the undisturbed columns using X-ray computed tomography. This method provided a set of digitized images corresponding to horizontal 3-mm-thick sections. The following parameters were measured using image analysis on each section: number of biopores, their volume, and their individual orientation calculated using an elliptical model of the earthworm channel. The profiles of these parameters through the columns showed that the burrow systems of L. terrestris and A. giardi, which are both anecic species, were very different in terms of total volume, number of burrows, burrow orientation and extension with soil depth. These results led us to conclude that the burrow system of L. terrestris can be considered as a permanent structure whereas that of A. giardi is closer to the burrow system of endogeic species. Received: 12 June 1998     

Assessment of the burrow system of Lumbricus terrestris, Aporrectodea giardi, and Aporrectodea caliginosa using X-ray computed tomography

Artificially packed soil columns were inoculated with individuals of different earthworm species (Lumbricus terrestris, Aporrectodea giardi or Aporrectodea caliginosa) and placed under controlled conditions in the laboratory. At the end of the incubation period, which lasted 8 months, three-dimensional reconstructions of the burrow system of each species were obtained using X-ray computed tomography. The particular features of the three burrow systems and the differences between them are discussed in terms of density, orientation and distribution of the burrows and the complexity of the network in relation to variations in soil depth and soil density. Received: 5 February 1997