全球气候变化对我国西北地区农业的影响

在比较系统总结全球气候变化对我国西北地区农业影响的主要研究成果的基础上,揭示了我国西北地区现代气候变化对全球气候变暖响应的基本特征,阐述了现代气候变化对土壤水分、地表蒸发和作物气候生产力的影响规律;并且比较全面地概括了西北地区冬、春小麦、玉米、马铃薯、冬油菜、棉花、胡麻、牧草、葡萄等9种主要农作物的生长发育、病虫害、种植面积、气候产量以及畜牧业活动等对气候变化的响应特征,发现气候变化对农业生产过程的影响利弊皆存,而且不同农作物对气候变化的响应特征差异较大.研究对西北地区农业生产具有比较重要的科学指导意见.     

重金属在食用菌中的富集及对其生长代谢的影响

本文报导食用菌对重金属的吸收积累性能及重金属对食用菌生长代谢的影响。从供试的香菇、凤尾菇、金针菇及木耳等食用菌研究表明:对Hg、Pb、As、Ni、Cd、Cu、Zn等重金属均有不同程度的富集作用,其中对Hg的富集是极显著的,但对Pb则不明显。从福建省食用菌生产点采样测定结果看,子实体中的重金属含量均不超标。上述重金属对食用菌生长均有不同程度的不良影响,尤其以Hg和As为突出。对产量影响的顺序以香菇最大、凤尾菇次之、金针菇较弱。重金属在一定范围内对香菇抗坏血酸氧化酶活性有激活作用,对纤维素酶有抑制作用。     

有机酸对Pb、Cd的土壤化学行为和植株效应的影响

有机酸对Pb、Cd的络合作用将其对土壤吸附Pb、Cd的影响和植株效应差异的研究表明,柠檬酸、草酸与Pb、Cd络合能力的大小与重金属本身的性质有关,络合作用影响土壤对Pb、Cd的吸附量,柠檬酸降低土壤对Pb、Cd的吸附,草酸则增加土壤对Pb、Cd的吸附.水培试验表明,柠檬酸可减轻Pb对小麦、水稻幼苗的毒害.柠檬酸对Cd的植株外观毒性效应影响不显著,但能促使植株茎叶、根中Cd含量下降.Pb和Cd复合处理条件下,Cd存在促使水稻植株对Pb吸收量增加,Pb存在抑制水稻植株对Cd的吸收.     

中华草龟荧光假单胞菌的分子鉴定及分析

从患病草龟病灶分离到几株优势菌,对该菌进行革兰氏染色、镜检,在普通肉汤培养基上进行观察。对分离菌株进行生化鉴定及16S rRNA基因序列的克隆、测定,并对其DNA进行测序,在NCBI上进行比对,构建系统进化树,对该菌的基因序列进行分析比对,基于形态学、生理学、生物化学和基因序列分析,将这些菌株鉴定为荧光假单胞菌。药敏实验结果表明该菌对复方新诺明、氧氟沙星、恩诺沙星、诺氟沙星高度敏感,对卡那霉素、四环素、庆大霉素、新霉素、氟苯尼考、氯霉素中度敏感,对头孢噻吩、甲氧苄啶有耐药性。     

2016-2018年医院血培养病原菌的分布及耐药性分析

目的:分析2016-2018年医院血培养病原菌的分布及其耐药性。方法:对2016年1月至2018年12月遵义医科大学附属医院各科室送检的血标本进行培养、鉴定和药敏试验,并对主要病原菌的分布和药敏结果进行统计分析。结果:2016-2018年分别分离出病原菌1459、1647、1711株,其中革兰氏阴性杆菌分别为占57.78%、55.43%、54.24%,革兰氏阳性球菌分别占37.97%、39.34%、43.25%,真菌分别占4.25%、5.22%、2.51%。2016-2018年,大肠埃希菌对头孢呋辛、头孢曲松的耐药率逐年降低,对厄他培南耐药率呈明显的升高趋势;肺炎克雷伯菌对头孢呋辛、头孢曲松、头孢吡肟的耐药率逐年降低,对头孢哌酮/舒巴坦、氨苄西林/舒巴坦耐药率上升;凝固酶阴性葡萄球菌对左氧氟沙星、苯唑西林、庆大霉素的耐药率明显降低,对环丙沙星、克林霉素的耐药率有明显的上升趋势;金黄色葡萄球菌对环丙沙星、克林霉素的耐药率明显升高,对左氧氟沙星的耐药率明显降低,对呋喃妥因、万古霉素、利奈唑胺、替加环素均不耐药;白色假丝酵母菌、热带假丝酵母菌对两性霉素B均不耐药,白色假丝酵母菌对氟康唑、伏立康唑不耐药,热带假丝酵母菌对氟康唑、伊曲康唑均高度耐药。结论:造成血流感染(BSI)的主要病原菌为革兰氏阴性杆菌,病原菌对常用的抗菌药物都有不同程度的耐药,临床应合理使用抗菌药物,以降低耐药性,并加强医院感染控制措施减少耐药菌的传播。     

令箭荷花紫色素稳定性的研究

研究了酸度、热、光、淀粉、糖、抗坏血酸、苯甲酸钠、金属离子对令箭荷花紫色素稳定性的影响。结果表明：该色素在酸性、中性稳定;光、热对色素有一定的降解作用;淀粉、糖、抗坏血酸、Na＋、Zn2＋对色素无不良影响;苯甲酸钠、Fe3＋、Cu2＋对色素有一定影响。     

9种农药对家蚕和蚯蚓的急性毒性

【背景】当前农药品种及其使用量日益增多,测试农药对环境生物的急性毒性成为农药环境安全监测的重要途径。【方法】采用食下毒叶法和药土法分别测定了甲氨基阿维菌素苯甲酸盐、阿维菌素、氰氟虫腙、螺螨酯、螺虫乙脂、嘧菌酯、苯醚甲环唑、戊唑醇、2,4-D二甲胺盐等9种农药对家蚕和蚯蚓的急性毒性,并根据其毒性等级划分标准进行分级,评价其对环境的安全性。【结果】甲氨基阿维菌素苯甲酸盐、阿维菌素、氰氟虫腙、螺螨酯、螺虫乙脂、嘧菌酯、苯醚甲环唑、戊唑醇和2,4-D二甲胺盐对家蚕的LC50(96 h)分别为2.05×10-3、8.59×10-4、2.79、250.48、11.52、272.18、2.50、1.93×10-2和534.47 a.i.mg·L-1,对蚯蚓的LC50(14 d)分别为11.05、6.29、100、100、100、100、99.13、115.31和100 a.i.mg·kg-1干土。其中,甲氨基阿维菌素苯甲酸盐、阿维菌素和戊唑醇对家蚕"剧毒",氰氟虫腙、螺虫乙脂和苯醚甲环唑对家蚕"高毒",其余农药对家蚕均为"低毒";阿维菌素对蚯蚓为"中毒",其余农药对蚯蚓均为"低毒"。【结论与意义】9种农药对家蚕和蚯蚓的急性毒性存在差异,为农药的合理使用和环境保护提供了依据。     

硼、锌对平欧杂交榛光合生理、结实和果仁品质的影响

通过对黑龙江省东宁地区的4年生平欧杂交榛（Corylus heterophylla×Corylus avellana）联合施用不同浓度的硼（0.2%、0.3%、0.4%）、锌（0.3%、0.4%、0.5%）肥处理,研究两种微量元素对平欧杂交榛光合生理、结实、果仁和叶片营养状态的影响。研究结果表明：（1）硼、锌对净光合速率影响显著,其交互作用对净光合速率影响极显著。（2）硼对出仁率影响极显著,对果仁重影响显著,对单果重和座果率影响不显著。锌对单果重和果仁重影响极显著,对出仁率影响显著,对座果率影响不显著。硼、锌交互作用对出仁率影响显著,对单果重、果仁重和座果率影响不显著。（3）硼、锌和其交互作用对果仁脂肪酸含量、果仁蛋白质含量影响不显著。硼、锌和其交互作用对4年生平欧杂交榛的生理和结实影响明显,提高了平欧杂交榛叶片的净光合速率,同时对果仁重、出仁率和单果重有不同程度的促进作用。本地区4年生平欧杂交榛硼、锌叶面施肥的浓度分别以0.3%和0.4%为宜。     

5种湿地植物对土壤重金属的富集转运特征

选择芦苇、水葱、千屈菜、扁秆藨草、长苞香蒲5种湿地植物进行盆栽实验,比较它们对土壤中的5种重金属镉、铬、汞、铅、锌的富集特性,分析重金属在各植物体和土壤中的动态分布,以评价所测植物对土壤中重金属的综合富集能力,为利用植物修复金属污染土壤提供理论依据和技术支持。结果表明:(1)种植湿地植物对土壤重金属的富集效果显著高于无植物对照,且随着处理时间的延长,土壤中重金属镉、铬、汞、铅、锌的含量均呈下降趋势。(2)湿地植物对重金属镉、铬、汞、铅、锌的富集效果差异显著,其中水葱根部对重金属镉的富集系数最大,芦苇根部对重金属铬、汞、铅、锌的富集系数均最大,千屈菜、扁秆藨草和长苞香蒲根部对5种重金属的富集系数均较小;芦苇地上部分对金属镉的富集系数最大,千屈菜地上部分对金属铬、汞、铅的富集系数均最大,水葱地上部分对金属锌的富集系数最大。(3)5种湿地植物对重金属镉、铬、汞、铅、锌的转移系数差异显著,其中扁秆藨草对土壤中镉、铬、铅、锌的转移系数均为最大,对铬和锌的转移系数均大于1,长苞香蒲对铬的转移系数大于1,仅次于扁秆藨草。其他3种植物对5种重金属的转移系数均小于1。研究表明,5种湿地植物对重金属Cd、Cr、Hg、Pb、Zn都有富集和转移的能力,但不同植物对不同重金属的富集效果不同。     

福建主要烟区烟蚜抗药性

采用浸渍法测定了福建三明、南平和龙岩烟区的烟蚜种群对6种常用杀虫剂的抗性水平.结果表明:与相对敏感种群相比,福建南平、三明和龙岩三个烟区烟蚜种群对灭多威的抗性倍数为11.68、5.60和3.69倍;对辛硫磷的抗性倍数分别为2.08、6.04和4.21倍;对吡虫啉的抗性倍数分别为2.72、2.70和5.89倍;对氰戊菊酯的抗性倍数分别为1.20、15.21和2.02倍;对高效氯氟氰菊酯的抗性倍数分别为1.74、14.87和1.19倍;对啶虫脒的抗性倍数分别为35.03、4.57和9.26倍.     

略论棕榈科与新分出的省藤科的系统分类、演化、区系地理及主要的经济用途

棕榈科原省藤亚科因其子房壁及外果皮被倒生、螺旋状排列的鳞片所覆盖,而区别于其他亚科,因而独立分出成一新科--省藤科。作者讨论了棕榈科的祖先种可能在石炭纪时,自原始裸子植物开以顿目在分化、衍生出苏铁目祖先种的进化干上,于白垩纪时分化出的一个分支。在棕榈科的祖先种出现不久后,在其进化的分支上,于白垩纪后期又分化出一旁支,成为棕榈科的姊妹科--省藤科的祖先种。从两祖先种分别再分化、衍生出现今分布地球上该二科的属与种。两科、尤其前者是被子植物、尤其是单子叶植物中最原始的类群之一。作者还提出棕榈科象牙椰亚科与贝叶棕亚科是该科最原始或较原始的两类群;槟榔亚科和腊材榈亚科是较进化的两类群;而水椰亚科祖先种可能源于象牙椰亚科的祖先种,但又演化为该科最进化与特化的类群。省藤科省藤亚科略比鳞果榈亚科原始。作者讨论了两科为泛热带分布的科,指出两科的"现代分布区"在南北两半球热带地区,少数种还延伸分布到两半球暖亚热带、甚至达中亚热带地区,分布区边缘最北达日本中部、中国长江流域及黄河下游的南部,美国加利佛尼亚州与佛罗里达州和地中海北部;最南达智利中部和新西兰南部;而"现代分布中心"在热带与暖亚热带的亚洲,中、南美洲,大洋洲及非洲的东、南、西部;但分布区的"密集中心"则在热带亚洲、热带中及南美洲、南太平洋群岛及非洲东南部。作者还介绍了近50年我国南方引种驯化成功的两科植物近400种(见^*图谱),其中少数为耐寒的种类,有的种已引种到长江流域或更北的地区。引种的大部分种都有其重要的经济用途,包括:1. 食用,如淀粉和树液可制"西米"或制糖,酿酒、醋或作饮料;果或种子榨油,供食用或工业用;某些种的嫩芽作蔬菜,甚至种子代咖啡饮用;2. 药用,有消炎、止血、活血、驱虫、抗癌等用;3. 建筑、工艺与日用品,包括不少种的树干供建普通房子、桥梁、小船;少数种可提制工业用蜡;许多种的纤维制高级缆绳和编织品;还制工艺品与日用品等;4. 代表热带景观的园林工程、绿化及美化环境的观赏树和人行道树及建造园林景观生态类型的树种等。     

On molecular taxonomy: what is in a name?

Gene sequences of small portions of the genome are often used for premature detailed taxonomic changes, neglecting polyphasic taxonomy, which should also consider phenotypical characteristics. Three examples are given: (i) Recently, members of the genera Eperythrozoon and Haemobartonella have been moved, correctly so, from the Rickettsiales to the Mycoplasmatales, but were assigned to the genus Mycoplasma, mostly on the basis of 16S rRNA sequence analysis. Not only is the 16S rRNA sequence similarity between 'classical' Mycoplasma and these species of Eperythrozoon and Haemobartonella less than that between some other well-recognised bacterial genera, but their biological differences amply justify their classification in different genera of the Mycoplasmatales. Furthermore, the move creates considerable confusion, as it necessitates new names for some species, with more confusion likely to come when the 16S rRNA sequences of the type species of Eperythrozoon, a name which has priority over Mycoplasma, will be analysed. (ii) In the Rickettsiales, members of the genera Anaplasma, Ehrlichia, Cowdria, Neorickettsia and Wolhbachia are so closely related phylogenetically on the basis of 16S rRNA sequences, and for some also of groESL operon sequences, that they have recently been fused, correctly so, into one family, the Anaplasmataceae, while the tribes Ehrlichieae and Wolbachieae have been abolished. Sequence diversity within the 'classical' genus Ehrlichia has led to classifying E. phagocytophila (including E. equi and the agent of human granulocytic ehrlichiosis), E. platys and E. bovis in the genus Anaplasma, while others have been retained in Ehrlichia, which also includes Cowdria ruminantium. E. sennetsu and E. risticii have been transferred to the genus Neorickettsia. 16S rRNA and GroEL sequences of 'classical' Anaplasma and some members of 'classical' Ehrlichia do show a close relationship, but differences in citrate synthase gene sequences, the GC content of this gene, and sequences of the gene encoding the beta-subunit of RNA polymerase, not to speak of the phenotypical differences, do not justify the fusion into one genus. Because of the phylogenetical diversity in Ehrlichia it is recommended that a new genus name be created for the E. phagocytophila genogroup (and E. platys and E. bovis). (iii) One of the conclusions of studies on the phylogeny of ticks of the subfamilies Rhipicephalinae and Hyalomminae, based on nucleotide sequences from 12S rRNA, cytochrome c oxidase I, the internal transcribed spacer 2, 18S rRNA, as well as morphological characters, is that Boophilus should be considered as a subgenus of Rhipicephalus. While Boophilus and Rhipicephalus are undoubtedly close, the obviously important morphological and biological differences between the genera Rhipicephalus and Boophilus are thus overruled by similarities in the sequences of a number of genes and this leads to considerable confusion. Polyphasic taxonomy amply justifies maintaining Boophilus as a separate genus, phylogenetically near to Rhipicephalus. This note is a plea for a cautious and balanced approach to taxonomy, taking into account molecular genotypical information, as far as is possible from different genes, as well as phenotypical characteristics.     

Effects of Microbial and Other Antagonistic Organism and Competition on Entomopathogenic Nematodes

Antagonistic factors, broadly identified as antibiosis, competition and natural enemies, impact on entomopathogenic nematodes. Antibiosis can occur through the release of plant chemicals from the roots into the soil, which may adversely affect the host-finding behavior of the infective stage nematode, or the presence of these chemicals in the host insect may negatively affect nematode reproduction. In laboratory studies, intra-specific and inter-specific competition reduces nematode fitness, and inter-specific competition can cause local extinction of a nematode species. For example, after concomitant infection of a host, a steinernematid species usually excludes a heterorhabditid species. The mechanism for the steinernematid superiority has been postulated to be a bacteriocin(s) produced by Xenorhabdus, the symbiotic bacterium of the steinernematid, which prevents Photorhabdus, the symbiotic bacterium of the heterorhabditid, from multiplying. Inter-specific competition between two steinernematid species shows that both can co-exist in a host, but one species will eventually prevail in the environment. By having different foraging strategies, however, both steinermatid species may co-exist in the same habitat. An important issue is whether the introduction of an exotic entomopathogenic nematode species will competitively displace an indigenous nematode species. Although the environmental risks are small, the recommended policy is that the introduction of exotic nematodes be regulated. With other pathogens, entomopathogenic nematodes can out-compete entomopathogenic fungi, but not Bacillus thuringiensis, for the same host individual when both the nematode and entomopathogen are applied simultaneously. The best studied natural enemy is the nematophagous fungus, Hirsutella rhossiliensis, which causes higher mortality in Steinernema glaseri compared with Heterorhabditis bacteriorphora. Differential susceptibility to the fungus may be associated with the retention of the second-stage cuticle by H. bacteriophora. Invertebrate predators including mites and collembolans feed on entomopathogenic nematodes. Although a number of studies have been conducted with antagonists, there is a dearth of field data. We suggest that long-term research plots be established where natural populations of entomopathogenic nematodes occur and include antagonists as a component of such studies.     

山东山旺Palaeomeryx化石的初步研究

Palaeomeryx 在含义、性质和分类位置上,一直是一个争论较多的属.最近在山旺发现的 Palaeomeryx 完整骨架,为解决上述问题提供了有价值的资料和证据. Palaeomeryx 雄性具有一对眶上"皮骨角"和单一的"枕顶角".根据共近裔性状的分析,本文作者认为 Palaeomeryx 应该归入长颈鹿,作为这一支中最早分出的一个旁支.长颈鹿和鹿科有较近的亲缘关系,而和牛科的关系较远. Palaeomeryx 大概位于 Blastomeryx 和 Leptomeryx 之间,从反刍类主干中分出.山旺的材料,代表本属中一个较原始的新种: Palaeomeryx tricornis. 它的时代,可能相当于欧洲的 MN4 或 MN5.     

世界柽麦蛾属支序生物地理学研究（鳞翅目： 麦蛾科）

基于对世界柽麦蛾属昆虫外部形态和外生殖器的形态学研究,选择了66个性状演变系列,通过PAUP*4b10软件对柽麦蛾属51种昆虫进行了支序系统学分析。分析结果认为heluanensis种团并不是一个单系群,柽麦蛾属被重新作了7个种团的划分。在支序系统学分析的基础上,柽麦蛾属昆虫的14个地理分布区域等级关系被重建,显示出古地中海地区复杂的历史,同时说明在该属分布格局中扩散事件客观存在。     

Phylogenetic analysis of the Brachyura (Crustacea, Decapoda) based on characters of the foregut with establishment of a new taxon

The Brachyura, within the decapod crustaceans, is one of the most species-rich taxa with up to 10 000 species. However, its phylogenetic history, evolution and fossil record remain subjects of controversy. In our study, we examined the phylogenetic relationships of the Brachyura based on morphological characters of the foregut. The cladistic analysis supports a monophyletic Brachyura including the Dromiidae and Raninidae. A clade comprising Dromiidae and Dynomenidae forms the most basal assemblage within the Brachyura, followed by the Homolidae and Latreilliidae. As a result, neither Podotremata nor Archaeobrachyura form a clade. In contrast, foregut data suggest that the classical taxon Oxystomata, comprising Calappidae, Parthenopidae, Dorippidae, Leucosiidae, Cymonomidae and Raninidae, is monophyletic. This makes the Heterotremata paraphyletic or polyphyletic. A newly established taxon, Neobrachyura, embraces some representatives of the Heterotremata and the monophyletic Thoracotremata.     

Floral elaiophore structure in four representatives of the Ornithocephalus clade (Orchidaceae: Oncidiinae)

Background and Aims A significant number of species assigned to the Neotropical orchid sub-tribe Oncidiinae reward insect pollinators with oil produced in floral glands termed elaiophores. The latter may be glabrous (epithelial elaiophores) or hirsute (trichomal elaiophores). Although the detailed anatomy and ultrastructure of epithelial elaiophores have been studied for a number of genera, such as Oncidium Sw., Gomesa R. Br. and Trichocentrum Poepp. & Endl., hitherto, trichomal elaiophores have been investigated only for a single species of Oncidiinae, Ornithocephalus ciliatus Lindl. Furthermore, this is the only representative of the Ornithocephalus clade to be investigated to date. Here, an examination is made of the elaiophore anatomy and ultrastructure of a further four species currently assigned to this clade (Ornithocephalus gladiatus Hook., Phymatidium falcifolium Lindl., Zygostates grandiflora (Lindl.) Mansf. and Zygostates lunata Lindl.) and the results compared with those obtained for other Oncidiinae. Methods Elaiophore structure was examined for all species at three stages of flower development: closed bud, first day of anthesis and final stage of anthesis, using light microscopy, fluorescence microscopy, scanning electron microscopy, transmission electron microscopy and histochemistry. Key Results Elaiophores of O. gladiatus occur upon the lateral lobes of the labellum and display characters intermediate between those of typical epithelial and trichomal elaiophores, in that they are largely glabrous, consisting mainly of cuboidal epidermal cells, but bear short, unicellular hairs proximally. By contrast, the elaiophores of all the other species investigated occur on the callus and are of the trichomal type. In P. falcifolium, these unicellular hairs are capitate. In all species, oil secretion commenced at the closed floral bud stage. Ultrastructurally, the mainly trichomal elaiophores of the four representatives of the Ornithocephalus clade closely resembled the epithelial elaiophores of other Oncidiinae, in that their cells displayed an organelle complement typical of lipid-secreting cells. However, in some taxa, a number of noteworthy characters were present. For example, the elaiophore cuticle of O. gladiatus and P. falcifolium was bi-layered, the outer layer being lamellate, the inner reticulate. The cuticle of Z. grandiflora and Z. lunata was also lamellate, but here, a reticulate layer was absent. Accumulation of secreted oil resulted in the localized distension of the cuticle. Cuticular cracks and pores, however, were absent from all species. The walls of the secretory cells of Z. grandiflora were also atypical in that they had short protuberances or ingrowths, and contained cavities which are thought to be involved in the secretory process. Conclusions Of the species investigated, most displayed similar anatomical organization, their trichomal elaiophores occurring on the labellar callus. They, thus, differ from many other members of the Oncidiinae, where epithelial elaiophores are found either on the callus, or on the lateral lobes of the labellum. However, ultrastructurally, all elaiophores, whether those of representatives of the Ornithocephalus clade, or those of other oil-secreting Oncidiinae, possessed a similar complement of organelles, regardless of whether the elaiophores were trichomal or epithelial. In view of the latter, and the similar chemical composition of oils derived from all Oncidiinae investigated to date, it is probable that position and type of elaiophore, and possibly the structure of the overlying cuticle, play an important role in pollinator selection in these oil-secreting orchids.