生物多样性重要区域识别——国外案例、国内研究进展

生物多样性丧失已经成为全球重大环境问题之一,重要区域或重要物种的识别是制定和实施保护计划的首要步骤,生物多样性保护的优先性研究成为保护生物学研究的焦点之一。优先保护的概念很早就被提出,保护国际(Conservation International,CI)一直倡导的热点地区途径受到国际社会的重视,生物多样性重要区域(KBAs)可以是综合的,也可以是单一类群的重要区域,如不同的国家已经开展了鸟类重要区域(important bird areas,IBAs)、植物重要区域(important plants areas,IPAs)、蝴蝶重要区域(prime butterfly areas,PBAs)和两栖爬行动物重要区域(important amphibians and reptiles areas,IARAs)等的识别研究工作。集中力量优先保护一些重要的地区是目前生物多样性保护较为现实和高效的途径。以佛得角群岛(the Cape Verde Islands)、意大利(Italy)、荷兰(the Netherlands)分别依据动物、植物单一类群或多个类群组合进行生物多样性重要区域识别为例,介绍了几个国家的生物多样性重要区域识别经验,概述国内在生物多样性重要区域识别领域的研究现状,详细介绍了海南岛生物多样性保护优先区识别案例,同时以国务院2010年批准实施的《中国生物多样性保护战略与行动计划(2011—2030年)》划定的32个陆地生物多样性保护优先区为例,提出中国未来应全面开展生物多样性本底调查,在充分获取生物多样性分布数据的基础上,依据植被类型和物种多样性以及受威胁因素等,在32个陆地生物多样性保护优先区内进一步客观准确地识别生物多样性重要区域(热点中的热点或重要区域中的重要区域),为中国未来的保护地规划、生物多样性监测、政策制定等提供科学支撑。     

罗汉果叶中黄酮甙元的研究

以罗汉果叶为原料提取出黄酮,黄酮经水解、溶剂萃取、柱层析等手段,得到高纯度甙元;经TLC、液相色谱、红外光谱、核磁共振法等分析手段进行结构鉴定,证实甙元分别为山奈酚、槲皮素。     

烟草中多羟基吡嗪的提取及其热裂解行为研究

从云南烤烟中提取分离得到了一个多羟基吡嗪化合物1,采用IR、MS和NMR进行了鉴定。并采用热裂解直接进气相色谱的方式,研究了该多羟基吡嗪的热裂解行为,分析鉴定了13个挥发性热裂解产物,占挥发性化合物总量的94．65％。     

玉米种子携带真菌的多样性研究

作者于2004年3月至2005年6月期间采集辽宁省广泛栽培的38个品种的玉米种子进行种子带菌分析。利用保湿培养检验法和分离培养检验法分别对种子表面粘附的真菌及内部寄藏真菌进行检验,通过纯化培养和形态鉴定,将几百个菌株鉴定到种。本文报道了从供试的玉米种子上分离得到的共16属的真菌,其中接合菌3属3种;子囊菌2属5种;有丝分裂孢子真菌11属18种,其中金黄色毛壳(Chaetromium aureumChivers)为中国新记录种。     

Evaluating Peptide Mass Fingerprinting-based Protein Identification

Identification of proteins by mass spectrometry (MS) is an essential step in pro- teomic studies and is typically accomplished by either peptide mass fingerprinting (PMF) or amino acid sequencing of the peptide. Although sequence information from MS/MS analysis can be used to validate PMF-based protein identification, it may not be practical when analyzing a large number of proteins and when high- throughput MS/MS instrumentation is not readily available. At present, a vast majority of proteomic studies employ PMF. However, there are huge disparities in criteria used to identify proteins using PMF. Therefore, to reduce incorrect protein identification using PMF, and also to increase confidence in PMF-based protein identification without accompanying MS/MS analysis, definitive guiding principles are essential. To this end, we propose a value-based scoring system that provides guidance on evaluating when PMF-based protein identification can be deemed sufficient without accompanying amino acid sequence data from MS/MS analysis.     

骆驼刺内生菌分离及代谢物活性成分分析

采用研磨法首次从新疆药用植物骆驼刺茎和叶等组织中分离得到20株内生菌并从中筛选出一株对作物致病菌的拮抗活性最强的内生菌XJAS-AB-11。通过形态学观察,生理生化特征以及16SrDNA序列分析最终将菌株XJAS-AB-11初步鉴定为枯草芽孢杆菌属(Bacillus sp.)。进一步对该拮抗菌株进行扩大培养,对其代谢产物进行初步研究,经硅胶柱色谱及TLC从具有抑菌作用的活性部位分离出活性单体C2和H2-2。紫外光谱、核磁共振氢谱及质谱分析证明化合物C2和H2-2均属于黄酮类化合物。研究表明,骆驼刺植物内生菌中蕴藏着较丰富的抗菌活性物质,是开发天然抗菌药物的潜在资源。     

基于径向基函数神经网络的心电图ST段形态识别

心电图的ST段是指QRS波的终点至T波的起点间的一个子波,其时间长度与心率有关,对ST段形态的识别有助于分析ST段变化的原因和确定缺血的部位。将模糊逻辑系统与神经网络相结合,利用基于自适应模糊系统的径向基函数神经网络对心电信号ST段的形态识别进行了研究。该网络比BP网络学习进度快,具有增量学习的能力,它能够识别学习外的新模式。研究取得了较好的识别结果。     

The impact of genetic diversity on the accuracy of DNA barcoding to identify species: A study on the genus Phellodendron

DNA barcoding is widely used in species identification, but there is considerable controversy regarding the extent of sampling in research methods. Some scholars have proposed that this small sample size underestimates the intraspecific genetic diversity, which would impact on the accuracy of DNA barcoding to identify species. In study, we selected all Phellodendron species (including P. amurense Rupr., P. chinense Schneid., and P. chinense var. glabriusculum Schneid.) as the materials, collected 59 P. amurense samples from 35 populations greatly to represent the genetic diversity, and analyzed the haplotype, genetic distance, barcoding gap, and Neighbor‐Joining (NJ) trees based on psbA‐trnH and internal transcribed spacer gene sequences. Additionally, a sampling simulation was conducted to assess the correlation between genetic diversity and the number of populations. Finally, analysis of critical geographical populations was performed. Based on analysis of haplotype, genetic distance, barcoding gap, and NJ trees, we found that eight P. amurense samples impacted on the effectiveness of DNA barcoding, which genetic information were very important to identify Phellodendron species. Moreover, the result of the NJ tree analysis performed the small‐scale P. amurense sample size did not completely match the objective phylogenetic relationship in Phellodendron. In simulation sampling analysis, the data showed the genetic diversity indexes at the same population level gradually decreased and stabilized as the number of simulation sampling populations increased. We found that 1–2 samples from over 24 populations based on uniform geographical distribution could represent 80% of the genetic diversity of P. amurense and ensure authenticity and reliability of DNA barcoding. Thus, we proposed it is particularly important adequately samples to cover infraspecific genetic diversity in order to ensure identification accuracy of DNA barcoding.     

芸香甙热裂解研究

在 5 0 0℃和 770℃两种温度下 ,采用热解直接进样的方式 ,研究了烟草中主要的多酚类化合物———芸香甙的热裂解产物。分别鉴定出了 2 4个和 2 3个裂解化合物。通过比较和分析这两种温度下的裂解产物发现 ,芸香甙可以裂解产生大量具有香味的产物。不同温度下的热裂解产物中 ,其中有 16个热裂解产物是相同的 ,但它们的相对含量却不一样。     

4种薯蓣属植物的分子鉴别和亲缘关系研究

为揭示薯蓣属植物的亲缘关系,根据叶绿体matK、rbcL、trnL-F和psbA-trnH序列片段,对小花盾叶薯蓣(Dioscorea sinopatviflora)、盾叶薯蓣(D.zingibiernsis)、黄独(D.bulbifera)和山药(D.polystachya)进行种间分子鉴别研究,并探讨这4个片段在薯蓣属植物系统发育上的意义。结果表明,4种薯蓣属植物共22份材料的matK、rbcL、trnL-F和psbA-trnH序列片段的长度分别为1026~1142 bp、1156~1178 bp、744~822 bp和355~599 bp。用PAUP 4.0b10和贝叶斯推断构建的系统发育树分析表明,云南的黄独与盾叶薯蓣的亲缘关系较近;小花盾叶薯蓣与盾叶薯蓣的亲缘关系很近;而非洲的黄独与云南的黄独的亲缘关系很远。但仅用这4个cpDNA片段还不能完全区分小花盾叶薯蓣和盾叶薯蓣,这说明基于这4个序列片段的系统发育证据与4种薯蓣属植物属内的分类划分并不十分吻合。