紫堇属（Corydalis DC.）植物的种子形态及其分类学意义

在光学显微镜下研究了湖北产紫堇属（Corydalis DC.）15种及2变型的种子形态特征。结果表明,其种子小,近圆形、扁圆形或肾形,黑色或深棕色,具油质体。油质体帽状、扇形、条形或不规则,紧贴种子表面或分离。根据种子表面形态,种子可分为4种类型：（1）表面光滑,如大叶紫堇（C.temulifolia Franch.）、川东紫堇（C.acu-minata Franch.）、巴东紫堇（C.hemsleyana Franch.ex Prain）、北岭黄堇（C.fargesii Franch.）、鄂西黄堇（C.shennongensis H.Chuang）和小药八旦子（C.caudata（Lam.）Pers.）;（2）表面具刺或疣状突起,如阜平黄堇（C.wilfordii Regel）、小花黄堇（C.racemosa（Thunb.）Pers.）、地锦苗（C.sheareri S.Moore）和珠芽地锦苗（C.sheareri S.Moore f.bulbillifera Hand.-Mazz.）;（3）表面具凹点状印痕,如刻叶紫堇（C.incisa（Thunb.）Pers.）、紫堇（C.edulis Maxim.）、地柏枝（C.cheilanthifolia Hemsl.）、蛇果黄堇（C.ophiocarpa Hook.f.et Thoms.）、北越紫堇（C.balansae Prain）和延胡索（C.yanhusuo（Y.H.Chou et C.C.Hsu）W.T.Wang ex Z.Y.Su et C.Y.Wu）;（4）表面具凹点状印痕,并被有疣状突起,如伏生紫堇（C.decumbens（Thunb.）Pers.）。种子大小、形状和表面形态以及油质体形态在种内相对稳定,对一些物种的划分具有较重要的意义。     

基于小波包变换的基因微阵列数据预处理方法

目的:基于阿尔茨海默病微阵列基因表达数据,分析研究微阵列基因表达数据预处理的新的有效方法。方法:首先采用标准差滤波、FSC(特征记分准则)和WPT-SAM(小波包变换-微阵列数据显著性分析)方法对微阵列基因表达数据进行预处理,比较处理后获得的基因数和FDR值;然后采用分类聚类方法对处理后的数据进行分类聚类和分层决策聚类,比较分类聚类结果。结果:标准差滤波和FSC方法获得的初筛基因数据较WPT-SAM方法多,但FDR值也高、后续分类聚类结果较WPT-SAM方法差。结论:WPT-SAM方法在预处理微阵列基因表达数据中,是比较灵活理想的分析方法。     

The relationship between specialization and local abundance: the case of helminth parasites of birds

Positive relationships are commonly observed between the abundance of a species in a locality and the frequency of its occurrence among localities on a larger scale. This pattern may not hold for parasitic organisms when the average abundance of a parasite among its hosts is related to the number of host species in which it occurs, because of the additive investment in specific adaptations to counter host immune responses required for each host species in a parasites repertoire. For a rigorous test of the hypothesis that there is a trade-off between the number of host species that can be successfully exploited and the average abundance of parasites in those hosts, one needs to take into account the phylogenetic (or taxonomic) distances among the host species used by a parasite. Differences in immune responses are likely to increase with increasing phylogenetic distances. The trade-off hypothesis was tested in a comparative analysis of 393 species of trematodes, cestodes and nematodes parasitic in birds surveyed from the same geographical area, using an index of host specificity that measures the average taxonomic distances between a parasites known host species. After correcting for the influences of parasite phylogeny and other potential confounding variables, mean abundance was negatively correlated with the average taxonomic distance among host species for nematodes, and with the variance in taxonomic distances among hosts for cestodes. In the case of trematodes, these variables covaried positively. The trade-off between average infection success and how taxonomically distant a parasites host species are from each other was only found in two of the three groups of helminths investigated, possibly because of compensating features in trematodes, such as their ability to multiply asexually in intermediate hosts. These results provide empirical evidence consistent with the hypothesis that specialization allows greater local adaptation and therefore greater local population abundance, supporting key predictions regarding the evolution of ecological specialization.Electronic Supplementary Material Supplementary material is available for this article at     

Monitoring of marine benthic communities and taxonomic resolution: an approach through diverse habitats and substrates along the Southern Iberian coastline

Studies conducted along the southern Iberian coastline validate macrobenthic community analyses at taxonomic levels higher than that of species. Twelve studies on littoral benthic communities, carried out by the same research team, were selected spanning both a variety of sampling strategies (spatial, temporal, spatio-temporal) and substrate/habitat types (sediment, rock, algae). In order to establish differences between the results obtained at the taxonomic levels of species, family and order, similarities among stations were calculated using Spearman’s coefficient for ranges. A subset of three studies was selected to investigate possible differences in ‘best-explaining’ environmental variables with taxonomic level. The environmental variables selected at species level were the same as those found at levels of family and order. It is concluded that studies at the different levels of taxonomic resolution (species, family, order) lead to similar results both with regard to relative community distributions and the environmental variables associated with these. The importance of this result for monitoring similar benthic communities is discussed.     

中国秋海棠属植物的叶表皮特征及其分类学意义

在光学显微镜下,对中国秋海棠属(Begonia)植物7组52种2变种的叶表皮进行观察。结果表明秋海棠属植物叶表皮形态在属内组间具有较大的相似性,表皮细胞为多边形或近多边形,垂周壁平直或弓形,大多数种类表皮细胞内具有晶体,气孔器仅分布于下表皮,且以不等型为主。叶表皮综合特征,例如表皮细胞形状,表皮毛类型,表皮细胞内晶体的类型和形态,气孔器形态以及与一些种类独有特征的组合,在种间,尤其在近缘种之间具有明显的差异。     

Estimating lagoonal biodiversity in Greece: comparison of rapid assessment techniques

An attempt is made to compare the results of different rapid biodiversity assessment techniques at the pan-Mediterranean, sectorial and local levels. A uniform multivariate pattern exists at the pan-Mediterranean and national (sectorial) levels: lagoons can be different when they host only a few species, but as species numbers increase, lagoons become homogenous in composition. Multivariate techniques cannot distinguish anthropogenically-impacted lagoons from those, which are naturally disturbed. In the pan-Mediterranean context it is the higher taxonomic levels, but in the national and local context it is the most abundant macrobenthic groups (polychaetes, molluscs and crustaceans) and meiobenthos which provide patterns closest to that derived from the species level. Taxonomic distinctness indices applied to polychaete and mollusc inventories provide meaningful results at most levels and scales of observation. These indices seem to be robust enough to discriminate anthropogenically impacted from naturally disturbed lagoons.     

The status of dwarf carnivores on Cozumel Island, Mexico

Cozumel Island in the Mexican Caribbean is inhabited by four carnivores, of which two, the Cozumel coati Nasua nelsoni and pygmy raccoon Procyon pygmaeus, are endemic species. The taxonomic status of a third carnivore, a dwarf gray fox Urocyon cinereoargenteus, is undetermined, but may deserve subspecific or species-level recognition. The fourth species, the kinkajou (Potos flavus), may be a recent introduction. We review the status of these carnivores, report our field observations and results of line transect and trapping efforts, discuss current threats to these taxa, and make recommendations for their conservation. A population density of 0.43 ± 0.27 coatis/km², and a total island population size of 150 ± 95 individuals, was estimated from 386 km of line transects in 1994–1995. Intensive trapping efforts (1479 trap-nights) in 2001 at multiple localities were unsuccessful. Pygmy raccoons were observed in the mangrove and coastal wetland areas of the island and in 2001 we captured 11 individuals with the same sampling efforts as for coatis (8.8 raccoons/1000 trap-nights). The gray fox is also apparently very rare on the island. While a few observations of the animals have been made (1984, 1994 and 2001), no animals were seen along transects and none were trapped. The primary threats to the persistence of these taxa include introduced congeners, introduced predators, parasite and disease spill-over from exotic animals, habitat fragmentation, hunting and collection as pets, and hurricanes. We suggest that the Cozumel coati, pygmy raccoon, and the Cozumel population of the gray fox be considered as Critically Endangered according to the IUCN classification system. Current conservation actions focusing on Cozumel carnivores are extremely limited. We recommend eradication of introduced species, maintenance of habitat connectivity, ex situ conservation programs, explicit public policies on land-use and sustainable development, public awareness campaigns, and continuous scientific research and monitoring.     

Development of a 16S rRNA gene-based prototype microarray for the detection of selected actinomycetes genera

Actinomycetes are known for their secondary metabolites, which have been successfully used as drugs in human and veterinary medicines. However, information on the distribution of this group of Gram-positive bacteria in diverse ecosystems and a comprehension of their activities in ecosystem processes are still scarce. We have developed a 16S rRNA-based taxonomic microarray that targets key actinomycetes at the genus level. In total, 113 actinomycete 16S rRNA probes, corresponding to 55 of the 202 described genera, were designed. The microarray accuracy was evaluated by comparing signal intensities with probe/target-weighted mismatch values and the Gibbs energy of the probe/target duplex formation by hybridizing 17 non-actinomycete and 29 actinomycete strains/clones with the probe set. The validation proved that the probe set was specific, with only 1.3% of false results. The incomplete coverage of actinomycetes by a genus-specific probe was caused by the limited number of 16S rRNA gene sequences in databases or insufficient 16S rRNA gene polymorphism. The microarray enabled discrimination between actinomycete communities from three forest soil samples collected at one site. Cloning and sequencing of 16S rRNA genes from one of the soil samples confirmed the microarray results. We propose that this newly constructed microarray will be a valuable tool for genus-level comparisons of actinomycete communities in various ecological conditions.     

繁缕和无瓣繁缕六个居群的数值分析

对繁缕（Stellaria media）和无瓣繁缕（S.apetala）的6个居群的57个性状进行Q－聚类和R－聚类的研究。结果表明：（1）Q－聚类中,用一条结合线,可以把繁缕的4个居群聚为一类,无瓣繁缕的2个居群聚为一类。这一结果支持肥繁缕和无瓣繁缕划分为两个物种;（2）R－聚类中,发现了呈现完全正相关、极大正相关和极大负相关的性状,并根据R－聚类的结果,运用一条适当的结合线,把繁缕和无瓣繁缕的57个性状划为5个类群,并分析了各性状的分类学意义。     

中国楼梯草属(荨麻科)几种植物的订正

根据对中国楼梯草属Elatostema植物标本的研究,将碧江楼梯草E．bijiangense归并入楼梯草E． involucratum,长叶墨脱楼梯草E．medogense var．oblongum和树志楼梯草E．shuzhii归并入墨脱楼梯草E． medogense,光茎钝叶楼梯草E．obtusum var．glabrescens归并入三齿钝叶楼梯草E．obtusum var．trilobula- tum,三裂楼梯草E．sinense var．trilobatum归并入对叶楼梯草E．sinense,赤水楼梯草E．strigulosum var．semitripilinerve归并入伏毛楼梯草E．strigulosum。