跗线螨属两新种：蜱螨亚纲：跗线螨科

本文记述了跗线螨属新种,长毛跗线螨Ｔａｒｓｏｎｅｍｕｓ ｌｏｎｉｓｅｔａｃｅｕｓｓｐ．ｎｏｖ．,泰氏跗线螨Ｔａｒｓｏｍｅｍｕｓ ｔｅｌａａｋｉ ｓｐ．ｎｏｖ．,并与近似种比较。模式标本促存在德国联邦农林生物研究中心,葡萄保护研究所及甘肃农业大学。     

福建迷跗线螨属一新种（蜱螨亚纲：跗线螨科）

本文记述迷跗线螨属Ｄａｉｄａｌｏｔａｒｓｏｎｅｍｕｓ一新种,卵斑迷跗线螨Ｄ．ｂｉｏｖａｔｕｓ ｓｐ．ｎｏｖ．,模式标本保存于福建省农科院植保所。     

福建角跗线螨属一新种（蜱螨亚纲：跗线螨科）

本文记述角跗线螨属一新种,罩角跗线螨Ｃｅｒａｔｏｔａｒｓｏｎｅｍｕｓ ｔｅｇｍｅｎ ｓｐ．ｎｏｖ．雌螨前足体背板呈罩状覆盖颚体,颚体背面具背中表皮内突。背片Ｈ上ｈ毛内前侧有１对孔隙ｉｈ。正模♀,副模１♀,采自福建南靖县乐土亚热带雨林自然保护区枯死树干的树皮内扁蝽科昆虫Ｍｅｚｉｒａ ｓｐ．体上。模式标本保存于福建省农科院植保所。新种与Ｃ．ｓｃｉｔｕｓ Ｄｅｌｅｏｎ相似,但与后者区别：１）背片Ｃ无斑纹     

中国跗线螨属二新纪录：蜱螨亚纲：跗线螨科

中国跗线螨属二新纪录（蜱螨亚纲：跗线螨科）林坚贞,张艳璇（福建省农科院植保所福州３５００１３）范青海（福建农业大学植保系福州３５０００２）ＴＷＯＮＥＷＲＥＣＯＲＤＳＯＦＴＡＲＳＯＮＥＭＵＳＦＲＯＭＣＨＩＮＡ（ＡＣＡＲＩ：ＴＡＲＳＯＮＥＭＩＤＡＥ）￥Ｌ...     

跗线螨属一新种：蜱螨亚纲：跗线螨科

本文记述德国跗线螨属１新种－Ｔａｒｓｏｎｅｍｕｓ ｇｅｒｍａｉｎｉｓｉｓ,ｓｐ．ｎ．。标本分别呆存在德国联邦农林生物研究中心（ＢＢＡ）,葡萄保护研究怕（正模♀和副模３♀♀）和甘肃农业大学植物保护系（副模３♀♀）。     

跗线螨属一新种（蜱螨亚纲：跗线螨科）

本文描述跗线螨属一新种,英氏跗线螨。新种以作者在德国进修时的导师Ｗ．Ｄ．Ｅｎｇｌｅｒｔ的姓氏命名。其特点是：２ａ毛生于第２表皮内突近远端１／３处,Ｃａ毛短于其相互间距;跗节Ⅱ的Ｔαβ感棒生于该节的基部;３ａ毛的位置不高于后中表皮内突的前端点。     

福建狭跗线螨属一新种(蜱螨亚纲:跗线螨科)

在研究跗线螨期间,我们发现一个新种。隶属于跗线螨科Tarsonemidae Kramer,1877狭跗线螨属Steneotarsonemus Beer,1954拟叉毛狭跗线螨Steneotarsonemus su-bfurcatus,新种模式标本保存于福建省农科院植保所。文中长度单位为μm。 拟叉毛狭跗线螨Steneotarsonemus subfurcatus新种(图1—6) 雄成螨 体长177—190(从颚体须肢的前端至生殖乳突的末端),体宽87—90(测量3个标本的数据)。     

中国跗线螨科二新纪录种（蜱螨亚纲：真螨目）

中国跗线螨科二新纪录种（蜱螨亚纲：真螨目）林坚贞,张艳璇（福建省农科院植保所福州３５００１３）范青海（福建农业大学植保系福州３５０００２）ＴＷＯＮＥＷＬＹＲＥＣＯＲＤＥＤＳＰＥＣＩＥＳＯＦＴＡＲＳＯＮＥＭＩＤＡＥＦＲＯＭＣＨＩＮＡ（ＡＣＡＲＩ：ＡＣＡ...     

血厉螨属一新种（蜱螨亚纲：厉螨科）

本文记述血厉螨属一新种,角跗血厉螨Ｈａｅｍｏｌａｅｌａｐｓ ｓｃｌｅｒｏｔａｒｓｕｓ ｓｐ．ｎｏｖ．,标本采自宁夏中卫县,该种足Ｉ跗节角化特别强,色深超过背板;躯体表面覆有白色膜状物为其主要特征。     

福建跗线螨属一新种：蜱螨亚纲：跗线螨科

本文记述采自福建双孢蘑菇Agaricus bisporus上跗线螨属一新种,主要寄生在蘑菇培养料内,常集中为害菌种块菌丝,直接影响出菇;其次寄生在蘑菇栽培种內,吸食蘑菇菌丝,造成菌丝不能萌发。     

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.