急性低温胁迫对南方鲇和瓦氏黄颡鱼耗氧率和呼吸频率的影响

[目的]为了研究急性低温胁迫对南方鲇和瓦氏黄颡鱼耗氧率和呼吸频率的影响。[方法]于24℃条件下测定南方鲇和瓦氏黄颡鱼经过不同温度(24、18、12、6、0℃)10 min低温胁迫后耗氧率(VO2)和呼吸频率(Vf)的恢复过程。[结果]结果表明:南方鲇在6、0℃胁迫后VO2和Vf表现为先下降、后上升然后缓慢回落的过程,其余组表现为先迅速上升然后缓慢回落的过程;瓦氏黄颡鱼只有0℃表现为先下降、后上升然后缓慢回落的过程,其余组表现为先迅速上升然后缓慢回落的过程。[结论]瓦氏黄颡鱼对急性低温胁迫抵抗力更高,但同样的低温胁迫瓦氏黄颡鱼需要消耗更多的能量。该研究为生产实践提供了基础数据。     

新诱剂对柑橘大实蝇成虫的诱杀效果

为了探讨新诱剂对柑橘大实蝇的防治效果,研究设计了地面覆草以及添加红糖等辅助措施,对比分析了新诱剂与果瑞特的诱杀效果和经济成本。结果表明,新诱剂对柑橘大实蝇的诱杀效果显著优于果瑞特,其橘园的虫果率仅为果瑞特处理的22.9%,扣除成本后,经济效益比果瑞特处理高209元/667m2;在地面自然长草的橘园,新诱剂的诱杀效果较好,其虫果率比地面没有长草的橘园的虫果率低39.57个百分点;在地面少草的橘园,红糖能显著提高其对柑橘大实蝇的诱杀率,其虫果率比不添加红糖的处理低18.45个百分点。     

长江中上游南方鲇遗传多样性的RAPD分析

采用随机扩增多态性DNA(RAPD)技术对取自长江中上游合川、木洞、涪陵、彭水、巫山、宜昌及岳阳7个江段的南方鲇(Silurus meridionalisChen)野生群体的遗传多样性进行了分析,24个随机引物共检测出327个位点(200~2500 bp)。各群体的多态位点比例在28.75%~48.62%之间,基因多样性指数为0.2047~0.3074。遗传距离显示长江中上游南方鲇各群体间有一定遗传分化,其中,木洞和合川群体间遗传距离最小为0.0537),而合川和岳阳群体间的遗传距离最大(0.1205),群体间遗传分化系数为0.1866。聚类分析(UPGMA)显示,7个群体聚为两大类群,合川和木洞亲缘关系最近,首先聚在一起,之后与彭水、涪陵、巫山群体相继聚类形成类群Ⅰ,岳阳和宜昌群体则聚类形成类群Ⅱ。Shannon指数分析表明,长江中上游南方鲇野生群体间种质资源状况良好,遗传多样性水平较高。     

Genetic diversity and relationship between cultivated clones of <Emphasis Type="Italic">Dalbergia sissoo</Emphasis> of wide geographical origin using RAPD markers

Random Amplified Polymorphic DNA (RAPD) polymor- phism was employed to assess the genetic diversity in the elite germ- plasm of Dalbergia sissoo. Sixty-seven clones that are under cultivation in northern India, originated from six different states of India and Nepal were analyzed with 30 RAPD primers that generated a total of 342 frag- ments out of which 290 were polymorphic. Total genetic diversity (Ht) varied between 0.01 and 0.37, with an average of 0.19. Shannon's In- formation index (I) varied between ...     

Assessment of genetic diversity in <Emphasis Type="Italic">Dalbergia sissoo</Emphasis> clones through RAPD profiling

We studied the genetic polymorphism among 29 clones of shisham (Dalbergia sissoo Roxb) belonging to different geographic regions using random amplified polymorphic DNA (RAPD) markers. Out of 30 primers used, only 20 primers generated polymorphism in amplified product. In total 232 bands were amplified with 20 primers, of which 192 (82%) were polymorphic with an average of 9.6 bands/primer. The resolving power (Rp) ranged from 2.14 (Primer 5) to 11.93 (Primer 4). Primer 4 and Primer 3 possessed high Rp value. Polymorphism information content (PIC) ranged from 0.15 (Primer 5) to 0.37 (Primer 4). Primer 4 amplified total 18 bands in 29 genotypes with PIC value of 0.37 hence; this set of primer was most informative. The similarity coefficient analysis revealed two clusters. The first cluster comprised of only 10 clones and the second major cluster comprised of 19 clones. The genetic similarity among 29 clones ranged from 25.86% (clone 10 and 235) to 100% (clone 19 and 59), suggesting a wide genetic base in shisham clones.     

东南亚产3种黑酸枝木木材构造特征比较研究

对从东南亚进口的刀状黑黄檀(Dalbergia cultrata)、黑黄檀(D.fusca)、阔叶黄檀(D.latifolia)3种黑酸枝木木材构造特征进行比较研究。结果表明,三者的宏观构造在材色、花纹和木屑酒精浸渍液方面有较大的差异;微观构造主要在轴向薄壁组织类型、木射线类型方面差异明显。     

Biomass and nutrient cycling in bamboo (Bambusa bambos) plantations of tropical areas

Biomass productivity and nutrient cycling in a Bambusa bambos plantation aged 4, 5, and 6 years were studied. The dry matter production of above-ground biomass increased progressively with age. Nutrient quantities in bamboo stands were in a range of 1–2 t ha^-1 for N and K, 0.5–1 t ha^-1 for Ca and Mg, and 0.1–0.2 t ha^-1 for P. Nutrient concentrations increased with the age of the plantation. About 10% year^-1 the nutrients present in the biomass of the bamboo stand are recycled to the soil by litter fall.     

块根紫金牛总黄酮提取工艺优化和不同产地、部位的含量比较

本研究采用正交试验分析和分光光度法,建立了块根紫金牛总黄酮含量测定的方法并比较分析其不同产地及不同部位总黄酮的含量差异。结果表明超声波法提取块根紫金牛中总黄酮的最佳提取工艺为：乙醇浓度60%,料液比1：70,提取时间50min,提取功率200W,提取温度70℃。另外,不同产地块根紫金牛中总黄酮含量顺序为：靖西〉那坡〉德保〉扶绥〉龙州〉武鸣;同一产地块根紫金牛根、茎、叶间总黄酮含量的高低顺序大致为：叶〉根〉茎。且通过精密度、重复性、稳定性和回收率实验来检测最佳提取工艺条件,结果显示该方法操作简便,结果准确,重复性好,RSD为0.788%,稳定性和回收率较高,平均回收率达96.20%。证明该方法可用于比较不同产地块根紫金牛药材中总黄酮的含量差异,对不同产地块根紫金牛的药材质量分析具有一定的指导作用。     

试论陈寅恪的义理阐释方法

融合中西、化合古今、铸旧创新,是民国学术的一大特色。学术大师陈寅恪结合中国传统的义理之学与近现代西方兴起的诠释学而形成的义理阐释方法,就是这一特色的典型表现,它也是陈寅恪治学的重要方法。陈的这一方法的内容可以概括为同情理解、视域融合、比较分析和心理研究,等等,其特点是强调阐释解读文本要去除“成见”、跨越时空、遥接作者之心于千百年之上;此外,以考据为基础的阐释和考据、义理相资为用,则既是其内容,又是其特色所在。     

中华农学会成立初期的史实考述

清末民初以来,农学界人士开始集结同人,以学会组织的形式推进农学研究。中华农学会是民国时期会员最为众多,组织最为稳固,会务最为活跃的全国性农学团体。但是,关于其成立的时间、地点以及首任会长等基本问题,学界长期以来存在诸多不同说法,就连当事人的回忆也各不相同。参照比勘各方留存资料,重新考订中华农学会成立及其初期的基本史实,尽量呈现其"近真"历史图像。