十二种落叶栎木的木材分类

本文研究了12种落叶栎木的解剖构造,按其主要特征,编制出识别木材的检索表。并运用木材定量解剖的方法,测定晚材管孔在纲格上的点分数、单位面积上的管孔数、密度指数以及它们之间的间距,将12种落叶栎木分为四组及二个单独的种。短柄枹栎和枹栎的木材解剖构造和定量解剖分析上都有显著地差异,可以将短柄枹栎单列为一种;麻栎和栓皮栎在形态分类上比较接近,而木材构造和定量解剖分析差别较大,栓皮栎可作为单独一个种,不包括在麻栎组内。     

Confirmation of hybrid origin in Arisaema (Araceae) using molecular markers

A population of hybrids between Arisaema triphyllum subsp. stewardsonii and A. dracontium was investigated using molecular markers to document the hybrid origin. Total genomic DNA was extracted from A. triphyllum, A. dracontium, and the hybrids, and subjected to sequence analysis of various regions of intergenic spacer and genes of chloroplast or intergenic spacer and genes of nuclear ribosome for single nucleotide polymorphisms (SNPs). Clustering was performed using the unweighted pair group method with averages (UPGMA) tested by bootstrap (BS). Hybrid origin could not be easily confirmed in some regions. However, dendrograms constructed with a combined sequence analysis of A. triphyllum 26S ribosomal RNA gene [sequence identification (SI) 467] plus A. tortuosum phytochrome C-like (phyC) gene (SI 468) were very similar to dendrograms constructed from sequences of all regions. This suggests that selecting SI 467 and SI 468 would be practical to identify hybrid origins involving two parental species. Clustering of hybrids together with the female parent in most target regions suggests that, in Arisaema, cpDNA is considered maternally inherited.     

如何提高动物解剖学及组织胚胎学的教学效果

根据动物解剖学及组织胚胎学的课程特点,结合教学实践,在教学过程中运用情景联想法、口诀记忆法、归纳总结法等教学方法,多媒体教学与板书教学相结合,并联系后期课程进行讲授,从而达到拓宽学生知识面、提高动物解剖学及组织胚胎学教学效果的目的。     

‘寒富’苹果短枝型特征的解剖学评价

以‘寒富’苹果及其亲本(‘东光’ב富士’)为试材,通过田间调查和解剖学方法,研究‘寒富’苹果短枝型结构特点.结果表明:‘寒富’苹果1 a生枝的平均长度和节间长度小于亲本;枝条粗度、节位数和尖削度高于亲本,具有明显的短枝型性状;‘寒富’苹果叶片厚度和叶脉突起度均大于亲本,叶片的栅栏组织细胞排列为3层,栅栏组织细胞形状较为细长,栅栏组织与海绵组织的比值大于1,叶片的气孔孔径大于亲本,但气孔密度小于亲本.‘寒富’苹果枝条皮部比率大于亲本,为43.11％;材部比率和材/皮小于亲本,分别为56.89％和1.32.由此可看出,‘寒富,苹果短枝型性状较明显,具有典型的矮化特征.     

中国木兰科单性木兰属的木材解剖

单性木兰木材解剖特征为:散孔材;管孔数目少;单管孔占优势。导管分子侧壁具螺纹加厚;底壁梯状穿孔,横隔条数多。木射线较少;射线组织异形Ⅱ型及Ⅲ型为主;无油细胞及结晶体。轴向薄壁组织轮界状,稀疏傍管型偶见。木材构造与近缘的木兰属有较大差别。     

循环经济作用机理探讨

从循环经济的内在本质、经济本质及其社会特征、核心作用和关键环节等角度,初步探讨了循环经济的作用机理。     

利用内标为基础的RT-PCR技术检测草莓皱缩病毒(SCV)和草莓镶脉病毒(SVBV)

[目的]通过对反应条件和参数的摸索与优化,建立多重RT-PCR检测方法,实现2种病毒的同时高效快速检测。[方法]通过CTAB法与试剂盒提取RNA,以优质的总RNA为模板,进行梯度PCR,结合扩增内标的检测体系,建立多重RT-PCR检测方法。[结果]建立了优化的SCV和SVBV的多重RT-PCR检测体系,可以对草莓田间植株进行快速稳定的病毒检测。[结论]该研究为草莓病毒检测提供一种方便、高效的分子生物学方法,为草莓无病毒苗的实际生产提供技术支撑。     

Effect of IAA and GA3 on the Anatomical Characteristics, Straw and Fiber Yield and Quality of Flax

IAA and GA₃ had increased the stem thickness by increasing that of cortex, phloem fibers and xylem. Each had increased straw and fiber yield/plant, but the effect was more pronounced with GA₃ than IAA. The percentage of long fibers, strength and fineness increased significantly with GA₃. The latter two properties decreased with IAA.     

鸡的肠神经(N.intestinalis)解剖

作为禽类特有的肠神经,始于泄殖腔背侧,沿直肠、回肠和空肠延伸至十二指肠升袢末端、胰管和胆囊管开口处。直肠段最粗,为中枢端,神经节明显而大,回肠段最细,神经节不明显,空肠段最长,为末梢端,沿途有多个神经节,并有分支至肠管和泌尿生殖器官。该条神经为荐部副交感神经的延续,全程没见交感神经和迷走神经纤维。部分个体在末端有与前肠系膜神经分支的吻合支。     

ANATOMY OF THE PORTAL AND HEPATIC VEINS OF THE DOG: A BASIS FOR SYSTEMATIC EVALUATION OF THE LIVER BY ULTRASONOGRAPHY

The objective of this study was to define, in detail, the anatomy of the portal and hepatic veins in the dog in order to establish a procedure for the systematic evaluation of the liver by ultrasonography. Anatomical details were obtained from the formalin fixed livers of ten dogs. The hepatic and portal veins were removed intact from these livers so that a detailed pattern of distribution could be established and the numbers of branches could be counted. Silastic casts were also made of the hepatic and portal veins of two livers, one in situ and one in which it had been removed. The former was to enable the relationship of the portal to the hepatic veins to be established as closely as possible within the animal and the other to provide a model of the distribution of each venous system within the liver. Contrast medium was infused into two other livers and radiographs taken to establish the relationship of each branch to each lobe. It was found that there was a consistent pattern of venous branching to each lobe of the liver in the dog with little variation between individual specimens. All liver lobes contained definite venous branches so that the left lateral and medial, quadrate, right medial and lateral, caudate and papillary veins could be distinguished in each venous system. We believe that an appreciation of this venous distribution will aid in the systematic evaluation of the liver during ultrasonography by enabling identification of each liver lobe. It should be of value for differentiating portal from hepatic veins and veins from dilated bile ducts.