广西被子植物二新记录属

在第四次中药资源普查中采集了大量标本,经过对这些标本进行仔细鉴定并查阅相关资料,确定其中两号标本为香茜属(Carlemannia Benth.)和粘腺果属(Commicarpus Standl.)植物。这两属植物在广西尚无报道,为首次记录。香茜属植物叶对生,子房下位,无托叶,雄蕊仅有2枚,这和茜草科相似但又不同,系统位置较混乱,以前曾放于茜草科( Rubiaceae)和忍冬科( Caprifoliaceae)中,最近该属和蜘蛛花属独立成香茜科( Car-lemanniaceae)。该属植物共有3种,沿喜马拉雅山脉向东一直分布到缅甸、越南北部。我国西藏东南、云南南部、广西西北部分布一种即香茜( Carlenannia chinenesis Hook. f.)。粘腺果属是紫茉莉科( Nyctaginaceae)主产热带地区的1个属,全世界约25种分布于热带非洲和阿拉伯半岛南部,在南亚、东南亚和墨西哥至热带美洲也有少量分布。中国产2种,其中广西产1种即中华粘腺果[ Commiaicarpus chinensis ( L.) Heim.]。该种植物分布广泛,从南亚次大陆向东至中南半岛、马来半岛,向北到我国西沙群岛、海南岛以及广州附近,在广西首次记录,产凤山县和凌云县。     

栅锈菌属一新种

本文报告在包头市采于茜草科六月雪[Serissa serissoides(DC.)Druce]上的锈菌一新种——六月雪栅锈菌[Melampsora serissicola Shang,R.X.Li et D.S.Wang]。茜草科和六月雪属为栅锈菌属真菌的新报道寄主科、属。     

陕西胡椒科一新记录属--胡椒属

报道了陕西省胡椒科一新记录属——胡椒属(Piper Linn．)及一新记录种——竹叶胡椒(P．bambusifolium Y．C．Tseng)。     

阿萨姆石丁香一新异名(英)

在修订茜草科绣球茜届（DunniaTutch．）过程中,笔者注意到Ridsdale在发表阿萨姆绣球茜（Dunniaassamica（Hook.f．）Ridsd．）新组合时,因忽视了花萼裂片和苞片的区别而将阿萨姆石丁香（HymenopogonassamicusHook．f）错误地转隶绣球茜属,现予以更正,并将其作为新改名的阿萨姆石丁香（Neohymenopogonassamicus（Hook．f．）Bennet）的新异名。     

阿萨姆石丁香一新异名(英)

在修订茜草科绣球茜属过程中,笔者注意到Ｒｉｄｓｄａｌｅ在发表阿萨姆绣球茜新组合时,因忽视了花萼裂片和苞片的区别而将阿萨姆石丁香错误地转隶绣球茜属,现予以更正,并将其作为新改名的阿萨姆石丁香的新异名。     

中国条脊牙甲科昆虫及一新种记述

条脊牙甲科(Hydrochidae)仅两属,我国仅报道一属二种,即越南条脊牙甲Hydrochus annamita Regimbart和日本条脊牙甲Hydrochus japonicus Sharp。该文记述了一新种脊鞘条脊牙甲Hydrochus rhytipterus sp.nov. 和一新记录种瘤鞘条脊牙甲Hydrochus binodosus Motschulsky。     

玉叶金花一新变种

报道了茜草科玉叶金花属玉叶金花一新变种,即白花玉叶金花Mussaenda pubescens Ait．f.var．alba X．F．Denget D．X．Zhang,var．nov．     

广东省野生植物一新记录科——蜡梅科

报道了广东省野生植物一新记录科--蜡梅科(Calycanthaceae)、一新记录属--蜡梅属(Chimonanthus)及一新记录种--山蜡梅(Chimonanthus nitens Oliv.).标本存放于华南农业大学林学院树木标本室(CANT).     

栀子花香飘初夏

初夏,栀子花开,乳白色的花朵或亭亭玉立,或若隐若现在翠绿的叶中,芳香扑鼻,深受人们喜爱。栀子(Gardenia jasmineoides)又名白蟾花,黄栀子、越桃、木丹、林兰,是茜草科栀子属的常绿灌木或小乔木,是名贵的花木之一。它在我国栽培历史悠久,早在2100多年以前司马相如《上林赋》就提到:“鲜支黄励”,鲜支即栀子,当时的栀子是重要的经济作物,其果实采收后可作黄色染料,用来染缯帛,可以给种植者带来利润。西汉司马迁《史记货殖列传》记载:“千亩栀茜,其人与千户侯等。”说明当时栀子是重要的经济作物。由于栀子花香芬芳,花瓣晶莹如玉,具有很高的…     

陕西省百合科一新记录属——独尾草属

报道了陕西省百合科一新记录属——独尾草属(Eremurus M.Bieb.),及一新记录种——独尾草(Eremurus chinensis Fedtsch.).     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.     

Composition and diversity of bird communities in Swedish farmland–forest mosaic landscapes

CapsuleThe amount of forest (at local and landscape scales) and occurrence of residual habitats at the local scale are shown to be the major factors influencing bird community composition in farmland–forest landscapes in central Sweden.

Aims To investigate the importance of local habitat and landscape structure for breeding birds in farmland–forest landscapes in central Sweden.

Methods Breeding birds were censused at 292 points. A detailed habitat mapping was made within 300 m of the points. Within a 300–600 m radius only two major habitats (forests and arable fields) were identified.

Results Cluster analyses of bird communities identified three site types that also differed in habitat composition: (i) partially forested sites in forested landscapes; (ii) heterogeneous sites with residual habitats in mosaic landscapes; and (iii) field-dominated farmland sites in open landscapes. A total of 19 of 25 farmland bird species (restricted to farmland or using both farmland and forest) had the highest abundance in farmland sites with mosaics of forest and farmland, while only six farmland species had the highest abundance in field-dominated sites. The bird community changed from being dominated by farmland species to being dominated by forest species (common in forest landscapes without farmland) at small proportions (10–20%) of forest at the local scale. A major difference in habitat composition between heterogeneous and field-dominated sites was the occurrence of different residual habitats (e.g. shrubby areas and seminatural grasslands). These habitats seemed to influence bird community composition more than land-use, despite covering <10% of the area. Seminatural grasslands were important for bird community composition and species-richness, but grazing seemed to be less important. Among different land-use types, cereal crops were the least preferred fields. Set-asides with tall vegetation and short rotation coppices were positively associated with species-richness of farmland birds.

Conclusion In general, the composition of the landscape was important for bird community composition, although amount and distribution of forests, occurrence of residual habitats and land-use of fields at the local scale had the strongest influence on bird community composition. The possible implications of these patterns for managing farmland–forest landscapes are discussed.     

Chemical constituents from the fruits of Rhus typhina L. and their chemotaxonomic significance

This work describes the isolation and characterization of twenty-nine compounds from the fruits of Rhus typhina L., including eleven flavonoids (1–11), eleven phenols (12–22), two pentacyclic triterpenes (23–24), two organic acids (25–26), one lumichrome (27), one courmarin (28) and one pyrimidine (29) on the basis of their spectroscopic data. Compounds apigenin (1), daidzein (4), orobol (5), 3′, 5, 5′, 7-tetrahydroxyflavanone (6), naringenin (7), butein (8), (-)-catechin (9), quercetin-3-O-α-L-(3″-O-galloyl)-rhamnoside (11), 2-hydroxybenzoic acid (13), 4-hydroxybenzaldehyde (14), vanillin (15), methyl 3,4-dihydroxybenzoate (16), 3,5-dihydroxybenzamide (18), tyrosol (19), caffeic acid (20), 3-(2,4,6-trihydroxyphenyl)-1-(4-hydroxyphenyl)-propan-1-one (21), phlorizin (22), friedelin (23), oleanolic acid (24), 4,4-dimethyl-heptanedioic acid (25), anthranilic acid (26), lumichrome (27), scoparone (28) and uracil (29) have not been recorded before in this plant. This is the first report on the occurrence of compounds 4–7, 9, 11, 13–14, 16, 18–21, 25–29 from the genus Rhus. Moreover, the chemotaxonomic significance of these isolated compounds was also summarized.