Effects of larval density and feeding rates on larval life history traits in Anopheles gambiae s.s. (Diptera: Culicidae)

Mosquito larval habitat determines the fitness, survivorship, fecundity, and vector capacity of emerging adults. We manipulated larval density and food provisioning in the laboratory to determine their effects on a number of life history parameters of Anopheles gambiae. Larval mortality was positively correlated with larval density. In addition, increased density skewed sex ratios that favored females.     

Structure of host-odour plumes influences catch of Anopheles gambiae s.s. and Aedes aegypti in a dual-choice olfactometer

The effects of structure, concentration and composition of host‐odour plumes on catch of female Anopheles gambiae Giles sensu stricto and Aedes aegypti (L.) (Diptera: Culicidae) were investigated in a dual‐choice olfactometer. We demonstrate that the fine‐scale structure of host‐odour plumes modulates capture of An. gambiae and Ae. aegypti. In both species homogeneous skin‐odour plumes result in trap entry, whereas homogeneous CO₂ plumes reduce trap catch. Reduced trap catch also result from combining skin odour with a homogeneous CO₂ plume. Trap capture rates in homogeneous CO₂ plumes were concentration‐dependent and differed between the two species. Electric nets placed in front of the trap entrances intercepted mosquitoes before they could enter the traps. This showed that An. gambiae flew along CO₂ plumes, but did not enter the traps. Survivorship analysis of the trap‐entry times of Ae. aegypti indicated interactions between the time until capture and treatment. The assay's duration therefore can alter the distribution in a dual‐choice olfactometer.     

广义紫菀属(菊科紫菀族)系统学研究的现状

广义的紫菀属(Asters.l.)曾是个大包大揽的类群,产于北美和欧亚大陆.Nesom主要根据瘦果的形态和细胞学性状对Asters.l.进行了评价,将北美紫菀类植物从Aster中独立出去,使Aster成为欧亚特有类群.但是,在欧亚各国对Aster有定为一属和分为十多个属等不同的分类学处理,分歧较大.狭义紫菀属(Asters.s.)与从Asters.l.中分出的各属之间的系统学关系,以及后者中某些属与北美紫菀类和紫菀族其他亚族间的系统学关系,都存在很大疑问.过去一直认为北美是Aster的发源地,现在欧亚Asters.l.的起源与演化需要重新研究,而青藏高原是探讨Asters.l.物种多样性形成的关键地区.DNA尤其是DNA序列资料在研究Asters.l.的系统发育和分类上将发挥关键作用.     

广义金钱菌属真菌研究概况

广义金钱菌属分布广泛,物种多样性丰富,包括了许多具有食药用价值的种类,具有较高的经济、生态和科研价值,但我国对该类真菌的关注较少。本文回顾了金钱菌属的建立与发展历程,以及分子生物学研究方法应用于该类真菌后其系统学的变化过程;介绍了欧洲与北美地区对栎裸脚伞复合群物种的区分过程;总结了广义金钱菌属真菌在生物防治和药用功效及化学成分研究等方面的研究进展。同时,还发现了各地对广义金钱菌属真菌的分类学研究水平差异较大,各地区研究水平不均衡和分子系统学研究不完善等问题,所以我国亟需对该类真菌资源调查与挖掘,以期为后续研究提供参考依据。     

土圞儿属和旋花豆属(豆科)的孢粉学研究

在扫描电子显微镜下,对豆科土儿属(Ap ios)和旋花豆属(Coch lianthus)7个种植物的花粉进行了观察.结果表明,2个属的花粉均为三孔沟,形状为三角球形或球形.土儿属的花粉可划分为2种类型:肉色土儿(A.carnea)的花粉外壁为典型的网状纹饰,其它种的花粉外壁较光滑,具颗粒状或短条纹状纹饰,研究结果不支持土儿属下亚属的划分;肉色土儿花粉外壁的网状纹饰式样可能反映了其在土儿属中处在较进化的位置.土儿属东亚分布种的花粉类型较为多样,原始和进化2种类型并存,表明东亚可能是土儿属的起源地和演化中心.旋花豆属的花粉特征和肉色土儿相似,说明两者之间的亲缘关系可能较近.     

中国伞形科狭义当归属果实表面微形态特征及其分类学研究

采用扫描电镜方法对中国31种狭义当归属植物的果实表面微形态特征进行了观察比较,结果表明:(1)狭义当归属植物外果皮细胞轮廓均不可见,但依据表面突起度可将其分为粗糙型和平滑型。(2)表面蜡质纹饰主要为粗条状和细线状,并呈现出或疏或密的交错或平行排布。(3)表面附属结构主要包括表皮毛、皮刺以及根枝状和块状结构等,并具有或多或少的颗粒状分泌物。上述果实表面微形态特征均表现出较丰富的多样性和一定的规律性,可作为狭义当归属果实形态研究的重要补充,为其物种鉴别和种间关系研究提供重要的参考依据。据此,该研究将31种狭义当归属植物分为4种类型:类型Ⅰ.果实表面无显著的蜡质纹饰,包括大巴山当归、带岭当归、紫花前胡和峨眉当归等4种;类型Ⅱ.果实表面有蜡质纹饰且较平滑,包括阿坝当归和东川当归等10种;类型Ⅲ.果实表面粗糙并有交错蜡质纹饰,包括城口当归和朝鲜当归等9种;类型Ⅳ.果实表面粗糙并有平行蜡质纹饰,包括东当归和当归等8种。本研究亦对属下的分类鉴定和部分近缘种的鉴别进行了探讨。     

Odour sensitivity of antennal olfactory cells underlying grooved pegs of Anopheles gambiae s.s. and An. quadriannulatus

In female mosquitoes of the anthropophilic species Anopheles gambiae Giles s.s. and the zoophilic An. quadriannulatus Theobald single sensillum recordings from grooved pegs were made. In both species, the majority of these sensilla responded to ammonium hydroxide, butylamine and propanoic acid, whereas a smaller part responded to acetone. Lactic acid, butanone, 3-methyl phenol and 1-octen-3-ol evoked responses in a minority of grooved pegs only. In An. gambiae these four substances evoked either excitatory or inhibitory responses. In An. quadriannulatus excitatory and inhibitory responses were only found on stimulation with lactic acid; butanone, 3-methyl phenol and 1-octen-3-ol only evoked inhibition in the pegs of this species. More than half of the grooved pegs responded to water vapour with an increase in spike frequency. As opposed to this, in some pegs inhibitory responses were found upon stimulation with vapour of low humidity. This suggests that grooved pegs may play a role in humidity perception in Anopheles. Dose-response relations were investigated for cells excited by ammonium hydroxide, butylamine and propanoic acid. Excitatory responses to these three substances were dose-dependent. No significant differences were found between the dose-response curves of the two species. It is concluded that in both species the host odours tested are not perceived by specialist cells. Combined information from generalist cells may provide a detailed `odour profile' of the host.     

Assortative mating in mixed swarms of the mosquito Anopheles gambiae s.s. M and S molecular forms,in Burkina Faso,West Africa

The molecular form composition of Anopheles gambiae Giles s.s. (Diptera: Culicidae) mating swarms and the associated mating pairs (copulae) were investigated during two rainy seasons (July to October, 2005 and July to November, 2006) in the villages of Soumousso and Vallée du Kou (VK7). Although the habitats of these villages differ markedly, sympatric populations of M and S molecular forms of An. gambiae s.s. occur in both places periodically. The main aim was to assess the degree to which these molecular forms mate assortatively. In Soumousso, a wooded savannah habitat, the majority of swarm samples consisted of only S‐form males (21/28), although a few M‐form males were found in mixed M‐ and S‐form swarms. In VK7, a rice growing area, the majority of swarm samples consisted of only M‐form males (38/62), until October and November 2006, when there were nearly as many mixed‐form as single‐form swarms. Overall, ～60% of M‐ and S‐form swarms were temporally or spatially segregated; the two forms were effectively prevented from encountering each other. Of the remaining 40% of swarms, however, only about half were single‐form and the rest were mixed‐form. Of the 33 copulae collected from mixed‐form swarms, only four were mixed‐form pairs, significantly fewer than expected by random pairing between forms (χ² = 10.34, d.f. = 2, P < 0.01). Finally, all specimens of inseminated females were of the same form as the sperm contained within their spermatheca (n = 91), even for the four mixed‐form copulae. These findings indicate that assortative mating occurs within mixed‐form swarms, mediated most probably by close‐range mate recognition cues.     

广义飞蛾藤属(旋花科)的分支系统学分析

基于33个广义的形态学性状,对广义飞蛾藤属Porana s．l．进行了分支系统学分析。经过简约性分析,得到了10个同等简约的分支树。10个同等简约树的严格一致化树表明,广义飞蛾藤属是一较为自然的分类群。与广义飞蛾藤属的孢粉学、种皮微形态学研究结果一致,分支分析的结果不支持将广义飞蛾藤属拆分为4个或5个独立的属,应在属内划分分类等级。在整个形态分支树中广义飞蛾藤属4个亚属呈并列2个分支,其中飞蛾藤亚属(subg．Porana)和白花叶亚属(subg．Poranopsis)形成姐妹群构成一分支,三翅藤亚属(subg．Tridynamia)和棒状亚属(subg．Dinetus)以姐妹群的关系构成另一支。鉴于分支分析的Bootstrap支持率不高,广义飞蛾藤属范畴的最后界定和属内等级的划分仍有待于进一步研究。     

Leaf epidermal morphology of Zanthoxylum s.l. (Rutaceae) from China

Leaf epidermis characters in 40 of ca. 250 species of Zanthoxylum (Rutaceae) were investigated using light microscopy (LM) and scanning electron microscopy (SEM). The stomata are anomocytic and exist only on the abaxial epidermis except in Z. nitidum, which also has stomata on the adaxial surface. The epidermal cells are usually polygonal or irregular in shape, with anticlinal walls straight, arched, repand, or sinuous. Under the SEM, the inner margin of the outer stomatal rim is nearly smooth, sinuolate or erose, and the cuticular membrane of the leaf epidermis is smooth, striate, or sometimes striate to wrinkled. These data of leaf epidermis of Zanthoxylum demonstrated that there exist many common characters between subgen. Fagara and subgen. Zanthoxylum, sug-gesting a close relationship between the two subgenera. The utility of some characters in identifying some species of Zanthoxylum was also discussed.     

广义飞蛾藤属(旋花科)花粉形态

对广义飞蛾藤属Porana s.l.18个分类群的花粉进行了光学显微镜和扫描电镜观察。除前人报道过的7种1变种外,其余均为首次报道。根据花粉粒的大小、形状、外壁纹饰、沟膜特征,该属花粉可细分为4个类型。研究结果不支持Staples(1993)把该属分为4个独立属的观点,而认为在属内划分为4个亚属较为合理。除毛果飞蛾藤外,花粉形态支持Staples对其它种、变种的归并。从花粉萌发孔类型上看,广义飞蛾藤属在旋花科内应处于较为原始的位置。     

乌拉甘草(豆科)的3个新异名

在考证了模式标本和查阅了大量腊叶标本的基础上,结合野外居群生物学调查工作,作者对分布于蒙古和我国境内的Glycyrrhiza alaschanicaGrankina、G.gobicaGrankina和G.soongoricaGrankina 3种甘草做了归并处理。认为它们属于乌拉甘草(G.uralensisFisch.ex DC.)的变异类型,均处理为乌拉甘草的异名。     

铁线莲属单性铁线莲组修订

对毛茛科铁线莲属Clematis L.的单性铁线莲组sect. Aspidanthera Spach s.l.进行了全面修订,确定此组共含72种和15变种,这些被归类于6个亚组中,其中包括首次描述的1系、5种和2变种,以及做出的2新等级。对单性铁线莲组的分类学简史和地理分布做了介绍。写出了组、亚组、系的形态特征和地理分布,分亚组检索表及各亚组的分种检索表;以及各种植物的形态描述、地理分布、生长环境等,并附有多幅插图。在研究了此组全部种类的标本之后,观察到此组几个重要形态特征的演化趋势：(1)萼片在数目上由     

A revision of Clematis sect. Aspidanthera s.l. (Ranunculaceae)

1　BrieftaxonomichistoryInthefirstrevisionofthegenusClematisL .madebydeCandolle (1818) ,some 17unisexualspecieswererecognizedandallputinthelargeheterogeneoussectionFlammulaDC .,andtogetherwithotherbisexualspecieswereclassifiedintofivegroups:C .peruvianaDC .andC .caracasanaH .B .K .(=C .guadeloupaePers.)with 14speciesofsect.Clematis,sect.Brachiatae ,sect.Meclatis,andsect.Viornasubsect.Connataewereplacedintothefirstgroup ,whichwasdiag nosedas“Floribuspaniculatis,foliispinnatimbipinnatim…     

Phylogeny and classification of the Sematophyllaceae s.l. (Hypnales,Bryophyta)

The Sematophyllaceae s.l. (Sematophyllaceae s.str. + Pylaisiadelphaceae) is one of the most diversified families of pleurocarpous mosses, distributed worldwide. The familial definition and subfamilial delimitation of the family have been controversial since their inception. Phylogenetic analyses were carried out using Bayesian inference, maximum likelihood, and maximum parsimony analyses. Our molecular phylogenetic analysis using five molecular markers (nad5, rbcL, rps4, trnL-F, and 26S) from mitochondrial, chloroplast, and nuclear genomes revealed the paraphyly of the Pylaisiadelphaceae and the monophyly of Sematophyllaceae s.l. Based on the molecular and morphological evidence, the Sematophyllaceae s.l. were further divided into six subfamilies, Taxithelioideae, Isopterygoideae, Pylaisiadelphoideae, Aptychelloideae, Platygyrioideae, and Sematophylloideae. The Taxithelioideae is established to accommodate Taxithelium, Taxitheliella, and Vernieri, the Isopterygoideae is established to accommodate Isopterygium and Yakushimabryum, the Pylaisiadelphoideae is newly circumscribed to accommodate Brotherella, Pylaisiadelpha, and Orientobryum, the Aptychelloideae is established to accommodate Aptychella, the Platygyrioideae is temporarily established to accommodate Clastobryella, Clastobryum, Gammiella, Platygyrium, and Trachyphyllum, the Sematophylloideae is resurrected to accommodate the Sematophyllaceae s.str., and Isocladiella, Isocladiellopsis, Mastopoma, Heterophyllium, Pseudotrismegistia, Trismegistia, and Wijkia are transferred to the subfamily. A new classification for the Sematophyllaceae s.l. is then proposed.     

国产广义大丁草属的订正及地理分布

依据最新广义大丁草属的概念对中国产这一属群的植物进行了订正,亦即中国有大丁草属Leibnitzia Cass,火石花属Gerbera Cass.和兔耳一支箭属Piloselloides(Less.)C.Jeffrey ex Cufod。并对一些名称进行了认真的查考和相应的分类学处理,讨论了相应的地理替代与地质历史的关系。经整理,中国大丁草属含4种,火石花属可能含6种,兔耳一支箭属含1种。以横断山为核心的中国西南部也许是该属群的一个多样化中心和分化中心。     

Conformational analysis of the Galpha(s) protein C-terminal region.

The C-terminal domain of the heterotrimeric G protein a-subunits plays a key role in selective activation of G proteins by their cognate receptors. Several C-terminal fragments of Galpha(s) (from 11 to 21 residues) were recently synthesized. The ability of these peptides to stimulate agonist binding was found to be related to their size. Galpha(s)(380-394) is a 15-mer peptide of intermediate length among those synthesized and tested that displays a biological activity surprisingly weak compared with that of the corresponding 21-mer peptide, shown to be the most active. In the present investigation, Galpha(s)(380-394) was subjected to a conformational NMR analysis in a fluorinated isotropic environment. An NMR structure, calculated on the basis of the data derived from conventional 1D and 2D homonuclear experiments, shows that the C-terminal residues of Galpha(s)(380-394) are involved in a helical arrangement whose length is comparable to that of the most active 21 -mer peptide. A comparative structural refinement of the NMR structures of Galpha(s)(380-394) and Galpha(s)(374-394)C379A was performed using molecular dynamics calculations. The results give structural elements to interpret the role played by both the backbone conformation and the side chain arrangement in determining the activity of the G protein C-terminal fragments. The orientation of the side chains allows the peptides to assume contacts crucial for the G protein/receptor interaction. In the 15-mer peptide the lack as well as the disorder of some N-terminal residues could explain the low biological activity observed.     

Molecular heterogeneity in the 18s DNA gene of Alternaria sp. and Fusarium sp. producing mycotoxins in rice and maize grains

Background

Food contaminated with fungi and their toxins is a problem that threatens many developing countries. Kingdom of Saudi Arabia depends on the exported grain and legume seeds.

柴胡皂甙s的结构鉴定

从南柴胡（ＢｕｐｌｅｕｒｕｍｓｃｏｒｚｏｎｅｒｉｆｏｌｉｕｍＷｉｌｄ．）根中分得５个三萜皂甙。根据理化性质和波谱数据,鉴定其中新皂甙为３β,１６α,２３,２８四羟基齐墩果烷１１,１３（１８）二烯３ＯβＤ吡喃葡萄糖基（１→６）［αＬ吡喃鼠李糖基（１→４）］βＤ吡喃葡萄糖甙,命名为柴胡皂甙ｓ（ｓａｉｋｏｓａｐｏｎｉｎｓ）。另４个皂甙分别为柴胡皂甙ａ、ｃ、ｂ１、ｂ２。     

Mitochondrial DNA analysis of Rhipicephalus sanguineus s.l. from the western Iberian peninsula

Rhipicephalus sanguineus Latreille (1806) (Ixodida: Ixodidae) is considered to be the most widely distributed tick and to have a vast range of habitats and hosts, including livestock, pets and wildlife. In addition to morphological differences, recent investigations using approaches based on molecular genetic markers have revealed the existence of different R. sanguineus lineages in different geographic regions. In this study, 475 ticks collected from dogs in the western Iberian peninsula were studied both morphologically and genetically, using 12S and 16S rDNA and COI gene markers in order to clarify the controversy over the systematic status of R. sanguineus sensu lato in Western Europe, and to compare the present data with those sourced from studies conducted in other regions of the world. Despite the high morphometric variability, particularly on spiracles in both genders and in female genitalia, data obtained with different genetic molecular markers show very low variability, suggesting the existence of a unique species. In addition, the phylogenetic analysis showed genetic uniformity, supporting the existence of a well‐defined clade consisting of R. sanguineus s.l. specimens from Western Europe that are distinct from R. sanguineus s.l. from Africa. Furthermore, these data corroborate the existence of a polymorphic species in Western Europe, which requires to be consensually redescribed in view of its medical and veterinary importance in pathogen transmission.