中国杜鹃花科植物新记录种——埃氏越橘

该文报道了国产杜鹃花科(Ericaceae)一新记录种,即埃氏越橘(Vaccinium eberhardtii Dop)。该种隶属于越橘属(Vaccinium)南烛组(Vaccinium sect. Bracteata),与同属于该组的南烛(V. bracteatum)和海岛越橘(V. wrightii)近缘,但与前者的区别在于花序梗、花梗、萼筒无毛,花冠球状坛形,药室背部明显具2个距,与后者的区别在于花梗较短,短于苞片,药室背后的距直立,长超过药管的一半。据文献记录,该种原来仅分布于越南中部和泰国,此次发现该种的分布范围可以北延至中国的广西东兴市的沿海地区,不仅丰富了越橘属分类、分布的数据,也为今后该属的分类学修订提供了新资料。凭证标本保存在中国科学院华南植物园标本馆(IBSC)和中国科学院广西植物研究所标本馆(IBK)中。     

越南苦苣苔科植物国家级分布新记录——大苞漏斗苣苔

漏斗苣苔属(Raphiocarpus Chun)是分布于中国至中南半岛一带的小属,主要产于中国华南西南抵越南北部至中部,但之前中越两国共有分布的该属物种仅有3个种。大苞漏斗苣苔[Raphiocarpus begoniifolius(Lévl.)Burtt]一度被认为是中国的特有种,仅分布在中国的广西西北部、贵州西南部、云南东南部和湖北西北部,尚未见有在越南的相关研究报道。该文首次报道了越南植物区系中大苞漏斗苣苔的国家级分布新记录,使得中越两国共有分布的该属物种上升到了4个种,并着重讨论了大苞漏斗苣苔与其近缘种长筒漏斗苣苔[Raphiocarpus macrosiphon(Hance)Burtt]的区别特征,进一步完善了越南所分布的漏斗苣苔属植物检索表。根据中越两国的各自与联合野外考察工作对该种的濒危现状进行了讨论,为中越两国开展该种乃至该属植物的保育提供了直接证据。凭证标本保存于越南生物资源与生态研究所标本馆(HN)中。     

Distribution, production and role of aquatic macrophytes in a southern Michigan marl lake

A typical marl lake of the Upper Great Lakes region has very few quantitatively important aquatic macrophytes. The macrophytes, however, dominate the total primary production of the lake. Submersed vegetation is extremely sparse on the shallow (less than I m) marl bench that characterizes the littoral of these lakes, and is completely dominated by one. little-known species (Scirpus subterminalis Torr.) between 1 and 7 m. A detailed investigation of the spatial and seasonal distribution of macrophytic species and biomass showed that S. subterminalis strongly dominated the lake (79% of total biomass). S. suhterminalis represented an almost pure stand (to 200 g m^?2 mean annual ash-free dry weight) at all times of the year at intermediate depths of macrophytic growth (1–6 m). Two species of Chara (of eight varieties and forms) were present in significant quantities (12% of total biomass; to 100 g m^?2) but were severely limited to shallow depths (0-S-l m) and protected areas. Several annual submersed angiosperms were present (9% of total biomass), but only two species were quantitatively important. Potamogeton illinoensis Morong. and P. praelongus Wulfen formed brief summer peaks (less than 100 g m^?2) at 3 and 4–6 m, respectively. A striking feature of the seasonal biomass distribution of Scirpus subterminalis was the higher, viable biomass (to 150g m^?2) throughout the winter under ice cover. Cyclic fluctuations of the S. subterminalis populations were discerned at different depths, each with different periodicities. The population at 2 m exhibited a fall peak; that at 4 m had a summer maximum. The lowest overall biomass of S. subterminalis occurred in the 2 m population in June. Chara populations at 0–2 m also exhibited a relatively constant biomass throughout the year. The appearance of Nitella at 7 m in July-October and of Chara at 5 m in September-October was interpreted as an interaction between light, thermal, and carbon stratification. Estimates of macrophytic productivity of perennial (‘evergreen’) species populations whose biomass remains relatively constant throughout the year were made employing several different methods of calculation and turnover factors. All methods resulted in productivity estimates in good agreement with the conservative value of 178 g m^?2 year^?1 for the entire lake. In comparison to the other components (phyto-planktonic, epiphytic and epipelic algae) of the primary production of Lawrence Lake, the aquatic macrophytes constituted a major portion (anuual mean 82·77 g C m^?2 year^?1 or 48·3 %) of the total production of the lake. The low diversity but relatively high quantitative importance of macrophytes in marl lakes is attributed to an adverse dissolved inorganic and organic chemical milieu which inhibits phytoplanktonic production and allows only certain adapted macrophytes to develop strongly. The phenomenon of perennial biomass levels throughout the year is believed to be much more common than previously suspected and has iikely resulted from adaptations of submersed macrophytes to ameliorated conditions of water and temperatures relative to the terrestrial situation in winter.     

New species of Barwing Actinodura (Passeriformes: Sylviinae: Timaliini) from the Western Highlands of Vietnam

On the basis of field observations and museum diagnosis of two specimens collected from Ngoc Linh in the Western Highlands (sometimes termed Central Highlands) of Vietnam, we here describe a new species of Actinodura. This species is most closely related to A. ramsayi of Burma, China, Laos, Thailand and Vietnam. Among other differences, it has a distinctive black crown - a feature otherwise unknown in the genus Actinodura , of which it is the southernmost known taxon. It occurs in montane evergreen forest from at least about 1100–2400 m asl and is likely to occur widely in this habitat and at this altitude elsewhere in the Western Highlands and in adjacent Laos. We present notes on the taxonomic affinities, ecology, behaviour and conservation of this new species.
A partir d'observations effectuées sur le terrain et de l'analyse en laboratoire de deux spécimens collectés au Mont Ngoc Linh dans le massif de Kontum, nous décrivons ici une nouvelle espèce du genre Actinodura. Cette espèce est la plus proche de A. ramsayi de Chine, Birmanie, Laos, Thaïlande et Viêt-nam. Elle possède une calotte noire distincte, un caractère jusqu'à présent inconnu du genre Actinodura dont elle occupè l'atire la plus mAeridionale connue. Cette espèce vit dans la forêt sempervirente de montagne entre 1100 m et 2400 m d'altitude et se trouve probablement dans un habitat et à une altitude similaires dans les montagnes environnantes du massif de Kontum et du Laos adjacent. Nous présentons ici des informations sur la taxonomie, l'écologie, le comportement et la conservation de cette nouvelle espèce.     

Absence of evidence for linkage between Booroola gene and genetic markers at 11 sheep blood polymorphic loci

Summary. Genetic linkage between the Booroola locus ( Fec ) and 11 sheep blood polymorphic loci (i.e. Tf, Hb, CA, OLA, and A, B, C, D, M, R, F41 red cell blood groups) was investigated in six large sire families (163 informative female offspring). The six sires tested were heterozygous for the Booroola allele ( Fec^B ) and for several genetic markers. No evidence in favour of linkage was found. Moreover, depending on the marker locus considered, linkage closer than or as close as the recombination frequency of 10–30% was excluded.     

Investigating the Comparative Biology of the Heterokonts with Nucleic Acids1

During the last decade investigations of heterokont protists utilizing molecular methods have challenged established biosystematic concepts. Most investigations emphasized the chloroplast genome or sequences from nuclear-encoded, ribosomal genes. Refinement of DNA isolation protocols, advent of “universal primers” and the polymerase chain reaction, automated sequencing and increased accessibility of DNA sequence databases have expanded data-gathering efficiency and increased dataset sizes. Because independent datasets have been easier to obtain, the testing of specific phylogenetic hypotheses has been facilitated, altering relationship concepts, primarily at phylum/class levels, and perceptions of cellular evolution. New approaches have emphasized ecological studies and extended studies to genus/species levels and poorly investigated genomes. This paper reviews studies documenting these impacts and identifies some current limitations. Additionally, new DNA sequence data from our laboratory on nuclear-encoded rDNA internal transcribed spacers and the chloroplast-encoded psb A gene suggest that these regions will provide taxonomic resolution for the Synu-rophyceae, at the class/order level and subspecies level, respectively.     

Vibrio cholerae laboratory infection of the adult house fly Musca domestica

The present study was designed to test the hypothesis that house flies may be capable of specifically harbouring ingested Vibrio cholerae in their digestive tracts. Flies were continuously fed green fluorescent protein (GFP)‐labelled, non‐O1/non‐O139 environmental strains of V. cholerae. Bacterial burdens were quantitatively measured using plate counts and localization was directly observed using confocal microscopy. Vibrio cholerae were present in the fly alimentary canal after just 4 h, and reached a plateau of ～10⁷ colony‐forming units (CFU)/fly after 5 days in those flies most tolerant of the pathogen. However, individual flies were resistant to the pathogen: one or more flies were found to carry < 180 V. cholerae CFU at each time‐point examined. In flies carrying V. cholerae, the pathogen was predominantly localized to the midgut rather than the rectal space or crop. The proportion of house flies carrying V. cholerae in the midgut was dose‐dependent: the continuous ingestion of a concentrated, freshly prepared dose of V. cholerae increased the likelihood that fluorescent cells would be observed. However, V. cholerae may be a transient inhabitant of the house fly. This work represents the first demonstration that V. cholerae can inhabit the house fly midgut, and provides a platform for future studies of host, pathogen and environmental mediators of the successful colonization of this disease vector.     

Correlations between genetic variance and adiposity measures,and gene × gene interactions for obesity in postmenopausal Vietnamese women

Although environmental factors are important, there is considerable evidence that genes also have a significant role in the pathogenesis of obesity. We conducted a population-based study to investigate the relationship between candidate genes for obesity (UCP1, UCP2, ADRA2B, ADRB3, LEPR, VDR and ESR1) and adiposity measures (body mass index, body fat percentage, weight, waist circumference and waist–hip ratio) in terms of individual gene and gene × gene interaction in models unadjusted and adjusted for covariates (age, years since menopause, educational level and total energy intake). Postmenopausal women with TC genotype of ESR1 gene had higher body fat percentage than those with TT genotype in the models unadjusted and adjusted for the covariates (P = 0.006 in adjusted model). In multiple logistic regression analysis, BsmI and ApaI SNPs of VDR genes were significantly associated with overweight and obesity. The UCP2–VDR ApaI interaction to susceptibility of overweight and obesity was first observed from logistic regression analysis, and then confirmed in the multifactor dimensionality reduction method unadjusted and adjusted for the covariates. This interaction had 69.09% prediction accuracy for overweight and obesity (P = 0.001, sign test). In conclusion, the study suggests the significant association of ESR1 and VDR genes with adiposity measures and the UCP2–VDR ApaI interaction to susceptibility to being overweight and obesity in postmenopausal Vietnamese women.     

合柱秋海棠——越南北部喀斯特地区秋海棠科盾叶一新种

描述了采自越南北部喀斯特地区秋海棠科（Begoniaceae）盾叶一新种,即合柱秋海棠（Begonia holostyla）。该新种在盾形叶和具黑色斑点的果实特征上相似于肿柄秋海棠（B. pulvinifera）,但是在合生到一半的花柱和新月形的柱头方面则不同,后者花柱基部合生,柱头2次分裂成1个螺旋状的带。此外,讨论了与近缘种肿柄秋海棠的形态差异和地理联系。