国产樟科一新名称

Phoebe reticulata Y. K. Li et X. M. Wang是P. reticulata Mez的晚出同名,建议用一个新名称P. liana Y. Yang替代P. reticulata Y. K. Li et X.M.Wang。     

蔷薇科植物二新异名

将太行梨(Pyrus taihangshanensis S. Y. Wang et C. L. Chang)作为新异名归并入木梨(P. xerophila Yü);将小瓣委陵菜(Potentilla parvipetala B. C. Ding et S. Y. Wang)作为新异名归并入三叶朝天委陵菜(P. supina L. var. ternata Peterm.)。     

东北蒿属新分类群

本文发表了中国东北菊科蒿属1个新亚种,3个新变种,即;北牡蒿Artemisia eriopoda Bge.subsp.jiagedaqiensis.G.Y.Chang et X.J.Liu,subsp.nov.,兴凯光沙蒿A.oxycephala kitag.var.xinkaiensis G.Y.Chang.et L.S.Wang,var.nov.,塔河柔毛蒿A.pubescens Ledeb.var.taheensis G.Y.Chang et L.S.Wang,var.nov.和线叶沙蒿A.desertorum Spreng.var.lineata G.Y.Chang,var.nov。     

河南榆科植物二新异名

将太行榆 Ulmus taihangshaneasis S．Y．Wang并入脱皮榆U．lamellosa Wang ex S．L．Chang ex L．K． Fu作为新异名;将毛叶朴Celtis pubescens S．Y. Wang et C．L. Chang并入朴树C．sinensis Pers．作为新异名。     

荩草属的新分类等级

本文报导荩草属Arthraxon Beauv.中4新组,4新种,2新变种,即小叶荩草组Sect.Microarthraxon S.L.Chen et Y.X.Jin,三蕊荩草组Sect.Triandroarthraxon S.L.Chen et Y.X.Jin,无篦齿组Sect.Monostrichi S.L.Chen et Y.X.Jin,篦齿组Sect.Tristrichi S.L.Chenet Y.X.Jin,多脉荩草A.multinervus S.L.Chen et Y.X.Jin,茅坪荩草A.maopingensis S.L.Chen et Y.X.Jin,贵州荩草A.guizhouensisS.L.Chen et Y.X.Jin,西南荩草A.xinanensis S.L.Chen et Y.X.Jin,疏序荩草A.xinanensis var.laxiflorus S.L.Chen et Y.X.Jin及光轴荩草A.lanceolatus var.glabrous S.L.Chen et Y.X.Jin.     

中国光沙蒿的一新亚种及一新变型

笔者于1987及1990年在东北、河北地区的采集中,发现菊科蒿属光沙蒿形态和体形特征有所差异,经过5年的播种,栽培观察,仍保持着植物野生的特色,故作为种下分类等级报导。 本文发表了东北产蒿属植物的一个新亚种和一个新变型。即:山海光沙蒿Artemisia oxycephala Kitag。subsp.shanhaiensis G.Y.Chang,L.S.Wang et H.X.Ma,subsp.nov.、太阳光沙蒿A.oxycephala Kitag.f.taiyangensis G.Y.Chang,L.S.Wang et H.X.Ma.f.nov.     

山东新植物

本文发表了山东产的柳属1新种即鲁中柳Salix luzhongensis X.W.Li et Y.Q.Zhu及黄龙柳Salix liouana C.Wang et Ch.Y.Yang, 小叶山毛柳Salix pseudopermollis C.Y.Yu et Ch.Y.Yang雄株补遗, 还有栎属1新变种, 即大果麻栎Querocus acutissima Carr.var.macrocarpa X.W.Li.et Y.Q.Zhu.     

鹿药属一新种

中甸鹿药新种图1Smilacina zhongdianensis H.Li et Y.Chen,sp.nov.Species haec nova S.henryi(Baker)Wang et Tang Similis.sed foliispetiolatis,perianthio haud tubuloso,filamentis basi manifeste connatis differt;floribus S.forrestii(W.W.Smith)Wang et Tang affinis,sed foliis subtuspubescentibus,segmentis perianthii liberis haud connatis in cupulam,stigmateconspicue tripartito et lobis reflexis distincta.     

中国石楠属的两个新种

正本文发表了中国贵州石楠属的两个新种, 即单齿石楠Photinia simplex Y.K.Li et X. M. Wang, 黎平石楠Photinia lipingensis Y. K. Li et M. Z.Yang。     

新疆唇形科新植物

本文发表了新疆唇形科的三个新种,即帕米尔分药花Perovskia pamirica C.Y.Yang et B.Wang;昆仑荆芥Nepeta kunlunshanica C.Y.Yang et B.Wang;塔城荆芥Nepeta tarhagatacia C.Y.Yang et B.Wang.     

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.