吉祥草的花部器官发生及其系统学意义

利用扫描电镜（SEM）观察了吉祥草（Reineckia carnea）（铃兰科）的花部器官发生发育过程。吉祥草花被片、雄蕊的发生方式是由近轴端向远轴端发生的逆单向型（reversed unidirection）,花发育后期花被片合生形成花被筒,花丝与之贴生。伴随花被片、雄蕊发生,三枚心皮也由近轴向远轴方向相继发生,随后彼此合生发育。花序顶部的花易发生花器官数目变异。结合早期花原基形态以及花器官数目变异情况分析,吉祥草的花被片与雄蕊可能是由共同原基分化而成。从花部器官发生式样和花被筒形成时间两方面比较吉祥草属、白穗花属和铃兰属的特征发现,三属中,铃兰属处于相对进化的位置,而白穗花属比吉祥草属更为原始。     

渐危植物鹅掌楸的授粉率及花粉管生长

对鹅掌楸Liriodendron chinense 3个自然居群连续3年直接统计落置柱头上的花粉量,其中 61.9％以上的柱头接受了花粉。每柱头上的平均花粉量为4.4～42.6粒,明显超过胚珠数2。授粉率是 结实率的6～8倍,鹅掌楸结实率低的主要原因可能不是由于花粉的限制。落置柱头的花粉几乎均可萌 发,少数花粉管穿过花柱道,经珠孔端进入胚囊,暗示花粉间存在着强烈的竞争。授粉率和柱头上的平 均花粉量与结实率呈正相关(R＝0.77,R=0.69)。在柱头上人工授同株和异株的花粉,花粉管生长速 率看不出明显差异,到达胚珠的时间在48～60 h之间。花开花药未裂时柱头上落置较高比例的花粉, 由于先期到达柱头的花粉最有可能受精,表明鹅掌楸有异交为主的繁育系统。人工处理包括套袋、套网、去除花被片,其结实率大大降低,而去雄后的结实率接近自然传粉结实率支持了这一观点。     

高原红细胞增多症患者红细胞二磷酸甘油酸和氧亲和力变化的探讨

在海拔４３００ｍ地区,对１８名移居汉族、２４名世居藏族和２１名高原红细胞增多症（ＨＡＰＣ）患者测定了２,３—二磷酸甘油酸（２,３—ＤＰＧ）和肺通气功能,并进行了血气分析。结果显示：ＨＡＰＣ患者的全血和红细胞内２,３—ＤＰ６浓度均显著高于健康组,但世居、移居健康组之间无明显差异。ＨＡＰＣ组的红细胞２,３—ＤＰＧ和Ｐｄｏ＿２呈显著负相关（ｒ＝—０．７７１,Ｐ＜０．０１）,而在健康组无显著相关（ｒ＝—０．２６,Ｐ＞０．０５）。ＨＡＰＣ组与健康组相比,ｐＨ、Ｐａｏ＿２和Ｓａｏ＿２降低,Ｐａｃｏ＿２和肺泡动脉氧分压差增高。ＨＡＰＣ病人Ｐ＿（５０）为３．７５±０．６６ｋＰａ,健康组为３．４０±０．１２ｋＰａ（Ｐ＜０．０５）,Ｐ＿（５０）与２,３－ＤＰＧ呈正相关（ｒ＝０．５９２,Ｐ＜０．０５）。ＨＡＰＣ组最大呼气中段流量和５０％肺活量最大呼气量明显低于健康组（Ｐ＜０．０１）。本研究提示：①ＨＡＰＣ患者的低氧血症可能与血中２,３－ＤＰＧ浓度过高有关;②轻度肺功能异常亦可促使红细胞进一步增多。     

血小板生长因子(PDGF-BB)刺激体外培养兔肺动脉平滑肌细胞DNA和蛋白质合成

应用细胞培养、３Ｈ－ＴｄＲ和３Ｈ－Ｌｅｕｃｉｎｅ掺入方法,观察血小板生长因子ＢＢ（Ｐｌａｔｅｌｅｔ－ｄｅｒｉｖｅｄＧｒｏｗｔｈＦａｃｔｏｒＢＢ）对体外培养兔肺动脉平滑肌细胞ＤＮＡ和蛋白质合成的影响。结果表明：（１）当ＰＤＧＦ－ＢＢ浓度为１０ｎｇ／ｍｌ时,３Ｈ－ＴｄＲ掺入值已较对照组显著增高（６２６２．５±４１２．９ｖｓ８３３．５±１２４．０,Ｐ＜０．０５）;当ＰＤＧＦ－ＢＢ浓度为２０ｎｇ／ｍｌ时,３Ｈ－Ｌｅｕｃｉｎｅ掺入值亦较对照线显著增高（１０２１２．８±６３８．３ｖｓ７３４０．３±１１９７．９,Ｐ＜０．０５）。（２）ＰＤＧＦ－ＢＢ浓度在５－２５ｎｇ／ｍｌ范围内,３Ｈ－ＴｄＲ,３Ｈ－Ｌｅｕｃｉｎｅ掺入值与剂量直线相关（ｒＤＮＡ＝０．９７,ｒｐｒｏｔ＝０．９０Ｐ＜０．０５）。说明ＰＤＧＦ－ＢＢ刺激体外培养兔肺动脉平滑肌细胞ＤＮＡ和蛋白质合成。     

高原红细胞增多症患者红细胞二磷酸甘油酸和氧亲和力变…

在海拔４３００地区,对１８名移居汉族、２４名世居藏族和２１名高原红细胞增多症（ＨＡＰＣ）患者测定了２,３－二磷酸甘油酸（２,３－ＤＰＧ）和肺通气功能,并进行了血气分析。结果显示：ＨＡＰＣ患者的全血和红细胞内２,３－ＤＰＧ深度均显著高于健康组,但世居、移居健康组之间无明显差异。ＨＡＰＣ组的红细胞２,３－ＤＰＧ和Ｐａｏ２呈显著负相关（ｒ＝－０．７７１,Ｐ＜０．０１）,而在健康组无显著相关（ｒ＝－０＼２     

渐危植物鹅掌揪的授粉率及花粉管生长

对鹅掌揪Ｌｉｒｉｏｄｅｎｄｒｏｎｃｈｉｎｅｎｓｅ３个自然居群连续３个直接统计落置柱头上的花粉量,其中结实率在６－８倍,鹅掌揪结实率低的主要原因可能不是由于花粉的限制,落置柱头的花粉几乎均可萌发,少数花粉管穿过花柱道,经珠孔端进入胚囊,暗示花粉间存在的强烈的竞争,授粉率和柱头上的平均花粉量与结实率呈正相关（Ｒ＝０．７７,Ｒ＝０．６９）在柱头上人工授同株和异株的花粉,花粉管生长速率看不出明显差异,到达     

山东四种草本植物的核型研究

本文对山东４种草本植物进行了染色体研究。结果表明：阿尔泰狗哇花（Ｈｅｔｅｒｏｐａｐｐｕｓａｌ ｔａｉｃｕｓ（Ｗｉｌｄ）Ｎａｖｏｐｏｋｒ）的染色体数目为２ｎ＝３６,核型公式为Ｋ（２ｎ）＝３６＝３６ｍ,核型“１Ａ”型;求米草（Ｏｐｌｉｓｍｅｎｕｓｕｎｄｕｌａｔｉｆｏｌｉｕｓ（Ａｒｄｕｉｎｏ）ＲｏｅｍｅｔＳｃｈｕｌｔ）的染色体数目为２ｎ＝１２,核型公式为Ｋ（２ｎ）＝１２＝８ｍ＋４ｓｍ,核型“２Ａ”型;红秋葵（Ｈｉｂｉｓｃｕｓｃｏｃｉｎｅｕｓ（Ｍｅｄｉｃ）Ｗａｌｔ）的染色体数目为２ｎ＝３８,核型公式为Ｋ（２ｎ）＝３８＝１４ｍ＋２２ｓｍ＋２ｓｔ,核型“２Ｂ”型;蟋蟀草（Ｅｌｅｕｓｉｎｅｉｎｄｉｃａ（Ｌ）Ｇａｅｒｔｎ）的染色体数目为２ｎ＝１８,核型公式为ｋ（２ｎ）＝１８＝１６ｍ＋２ｓｍ,核型“２Ａ”型。     

燕麦草（Arrhenatherum elatius）多倍体复合体的等位酶多样性研究

对欧洲及地中海地区燕麦草复合体２７个居群的等位酸电泳调查表明,燕麦草复合体维持比较高的等位酶多样性（Ｈｅ＝０．４４７,Ａ＝３．２９）,亚种间遗传分化较小（Ｇ（ＳＴ）＝０．０５３）;在四个亚种内,也维持着比较高的多样性（Ｈｅ：０．３２５—０．５３３）,各亚种内的基因多样度主要存在于居群之内,居群间分化较小．四倍体的基因多样性高于二倍体的．燕麦草复合体内居群间基因流较高,表明燕麦草繁育方式主要为风媒远交．对Ｎｅｉ氏标准遗传距离的ＵＰＧＭＡ聚类结果表明,四倍体是从二倍体有鳞茎的ｓｓＰ．ｂａｅｔｉｃｕｍ中产生的．     

七种药用植物的染色体研究

对山东７种药用植物的染色体进行了研究。结果表明：田旋花（ＣｏｎｖｏｌｖｕｌｕｓａｒｖｅｎｓｉｓＬ）的染色体数目为２ｎ＝７８;蜜柑草（ＰｈｙｌａｎｔｈｕｓｍａｔｓｕｍｕｒａｅＨａｖａｔａ）的染色体数目为ｎ＝８８;挂红灯（ＰｈｙｓａｌｉｓａｌｋｅｋｅｎｇｉＬｖａｒｆｒａｎｃｈｅｔｉ（Ｍａｓｔ）Ｍａｋｉｎｏ）的染色体数目为２ｎ＝２４,核型公式为Ｋ（２ｎ）＝２４＝２ｍ＋１８ｓｍ＋２ｓｔ＋２ｓｔ（ｓａｔ）,核型“２Ａ”型;无剌曼陀罗（ＤａｔｕｒａｓｔｒａｍｏｎｉｕｍＬｖａｒｉｎｅｒｍｉｓ（Ｊａｃｑ）ＳｃｈｉｎｚｅｔＴｈｅｌ）的染色体数目为２ｎ＝２４,核型公式为Ｋ（２ｎ）＝２４＝２０ｍ＋４ｓｍ,核型“１Ｂ”型;决明（ＣａｓｉａｔｏｒａＬ）的染色体数目为２ｎ＝２６,核型公式为Ｋ（２ｎ）＝２６＝２４ｍ＋２ｓｍ,核型“１Ａ”型;荔枝草（ＳａｌｖｉａｐｌｅｂｅｉａＲＢｒ）的染色体数目为２ｎ＝１６,核型公式为Ｋ（２ｎ）＝１６＝６ｍ＋１０ｓｍ,核型“２Ａ”型;车前（ＰｌａｎｔａｇｏａｓｉａｔｉｃａＬ）的染色体数目为２ｎ＝３６,核型公式为Ｋ（２ｎ）＝３６＝３２ｍ＋４ｓｍ,核型“１Ａ”型。     

糖基化对乙型肝炎表面抗原疫苗的影响

哺乳动物（ＣＨＯ）细胞表达的三种糖基化程度不同的乙肝表面抗原（ＨＢｓＡｇ）Ａ（含ＧＰ３０,ＧＰ２７,Ｐ２３）,Ｂ（含ＧＰ２７及Ｐ２３）,Ｃ（只有Ｐ２３）,在免疫原性、放置后抗原的稳定性以及对不同单克隆抗体亲和力等方面都有明显的差异;（１）免疫ＢＡＬＢ／Ｃ小鼠后血清中抗体工（ＥＤ５０）。平均结果为Ａ＝１：８０,Ｂ＝１：１１７,Ｃ＝１：１４,表明有糖基的ＨＢｓＡｇ疫苗对小鼠的免疫力明显高于无糖基的ＨＢ     

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.     

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     

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.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV