云南南部不同种源地小桐子遗传多样性的ISSR 分析

应用ISSR 分子标记方法对采自云南的8 个居群的小桐子( Jatropha curcas) 共158 个个体进行遗传多样性分析。8 个ISSR 引物共扩增到了67 个位点, 其中61 个是多态性位点。分析结果表明: (1) 云南小桐子的遗传多样性水平很高。在物种水平上, 平均每个位点的多态位点百分率PPB = 91.04% , 有效等位基因数N_e = 1.5244, Nei′s 基因多样性指数H_e= 0.3070, Shannon 多样性信息指数H_o = 0.4618; 在居群水平上, PPB = 55.04%, N_e = 1.3826, H_e = 0.2171, Shannon 多样性信息指数H_o = 0.3178。(2) 居群间的遗传分化低于居群内的遗传分化。基于Nei''s 遗传多样性分析得出的居群间遗传多样性分化系数G_st = 0.2944。AMOVA分析显示: 云南小桐子的遗传变异主要存在于居群内, 占总变异的63.50%, 居群间的遗传变异占36.50%。(3) 居群间的地理距离及遗传一致度并不存在相关性。鉴于以上指标, 我们推测云南小桐子可能来自不同的地区。     

内蒙古地区刺叶柄棘豆(Oxytropis aciphylla Ledeb.)种群遗传多样性分析

用ISSR分子标记对内蒙古地区刺叶柄棘豆(Oxytorpis aciphylla Ledeb.) 5个地理种群进行了种群遗传多样性分析。结果表明：刺叶柄棘豆种群具有较高的遗传多样性,11个ISSR引物扩增出215条带,总的多态位点百分率为98.14%,Shannon多样性指数I=0.2108,Nei基因多样性指数 H=0.341 6,种内总基因多样性(H_t) 为0.2108,种群内基因多样性(H_s)为0.160 4, 大部分遗传变异(76.11%)的遗传变异存在于种群内, 23.89%的遗传变异存在于种群间。遗传分化系数(Gst)为0.238 9,基因流(Nm)为1.592 9。5个居群间已有遗传分化趋势,遗传漂变不会引起遗传分化。UPGMA遗传距离聚类结果表明, 5个地理种群中,植被类型为荒漠草原的4个种群之间遗传距离较近,与1个荒漠种群距离较远。     

云南松居群核型变异及其分化研究

在分析研究6个云南松居群核型变异的基础上,应用常规统计方法和巢式分析方法,在常规染 色体水平上探讨云南松居群间、个体间和细胞间的变异式样及其分化。结果如下:(1)云南松居群核型 变异不显著,6个居群的核型公式均为2n=24m(6～10SAT),核型类型均为1A。(2)云南松居群仅相 对长度系数、臂比和次缢痕数目及其分布有小的变化。6个居群染色体相对长度系数(I．R．L)分别为: 滇中居群P1=16M₂+6M₁+2S;滇东南居群P2=14M₂+8M₁+2S;滇西居群P3=12M₂+10M₁+2S; 地盘松居群P4=14M₂+8M₁+2S;细叶云南松居群P5=14M₂+8M₁+2S;云南松与思茅松渗入杂交 居群P6=10M₂+12M₁+2S。(3)巢式方差等级分析表明,云南松染色体结构变异有10％左右来源于居群间,有90％左右来源于居群内个体间或细胞间。     

中华猕猴桃和美味猕猴桃自然居群遗传结构及其种间杂交渐渗

 利用9对SSR引物对中华猕猴桃（Actinidia chinensis）和美味猕猴桃（A. deliciosa）两近缘种的5个同域分布复合体和各自1个非同域分布居群进行了遗传多样性、居群遗传结构的分析以及种间杂交渐渗的探讨。结果表明：1）两物种共有等位基因比例高达81.13%,物种特有等位基因较少（中华猕猴桃：13.27%,美味猕猴桃：5.61%）,但共享等位基因表型频率在两近缘种间存在差异,而且与各同域复合体中两物种样本的交错程度或间距存在关联;2）两种猕猴桃均具有极高遗传多样性,美味猕猴桃的遗传多样性（H_o＝0 .749, PIC＝0.818）都略高于中华猕猴桃（H_o＝0.686,PIC＝0.799）;3）两猕 猴桃物种均具有较低的Nei’s居群遗传分化度,但AMOVA分析结果揭示种内异域居群间（F_ST=0.091 5）和同域复合体种间（F_ST=0.111 5）均存在一定程度的遗传分化;中华猕猴桃居群遗传分化（G_ST=0.086; F_ST=0.212 1）高于美味猕猴桃（G_ST= 0.080;F_ST=0.142 0）;4）同域分布复合体两物种间的遗传分化（G_ST=0.020）低于物种内异域居群间的遗传分化（中华猕猴桃：G_ST=0.086; 美味猕猴桃：G_ST=0.080）,同域复合体物种间的基因流（N_m＝7.89 -29.75）远远高于 同种异域居群间（中华猕猴桃：N_m =2.663; 美味猕猴桃：N_m=2.880）; 5）居群UPGMA聚类揭示在同一地域的居群优先聚类,个体聚类结果显示多数个体聚在各自居群组内,但各地理居群并不按地理距离的远近聚类,这与Mantel相关性检测所揭示的居群间遗传距离与地理距离没有显著性相关的结果一致。进一步分析表明两种猕猴桃的遗传多样性和居群遗传结构不仅受其广域分布、远交、晚期分化等生活史特性的影响,同时还与猕猴桃的染色体基数高 (x=29)、倍性复杂和种间杂交等因素密切相关,其中两种猕猴桃的共享祖先多态性和同域分布种间杂交基因渗透对两猕猴桃的居群遗传结构产生了重要影响。     

中国板栗自然居群微卫星（SSR）遗传多样性

采用8对微卫星分子标记对中国板栗(Castanea mollissima)的28个自然居群进行了遗传多样性与遗传结构分析。在849个个体上扩增得到128个等位基因, 每位点平均等位基因数(A)为16。中国板栗居群的平均预期杂合度(H_E)为0.678, 平均观察杂合度(H_O)为0.590。华中地区的中国板栗居群遗传多样性最高(A = 8.112, H_E = 0.705, H_O = 0.618), 其次为西北地区和华东地区, 而西南地区遗传多样性最低(A = 6.611, H_E = 0.640, H_O = 0.559)。基于无限等位基因模型(IAM)和基于逐步突变模型(SMM)的遗传分化系数分别为F_ST = 0.120和R_ST = 0.208。分子方差分析(AMOVA)结果表明中国板栗野生居群的遗传变异主要存在于居群内(87.16%)。Mantel检测揭示遗传距离与地理距离之间无显著相关性, 表明基因流不是主导中国板栗居群遗传结构的关键因素。华中地区(尤其是神农架及其周边地区)是中国板栗遗传多样性的现代分布中心, 因而应该得到优先保护, 同时该区域的野生板栗居群可优先作为栽培板栗遗传育种的材料和基因库。     

陕西唐棣遗传多样性和遗传分化的AFLP分析

采用扩增片段长度多态性分子标记技术对陕西省分布的6个野生唐棣居群的96个个体进行了遗传多样性分析, 以明确野生唐棣资源的亲缘关系,为唐棣资源的保护、良种选育和开发利用提供理论依据。结果显示：(1)从64对引物组合中筛选出8对扩增条带清晰、多态性高的引物组合,共扩增出277条清晰条带,其中多态性条带116条,多态性位点百分率为42.86%。(2)UPGMA聚类、主坐标分析(PCoA)和遗传结构分析结果相似,将6个陕西野生唐棣居群分成2大支,秦岭南北居群间遗传分化明显,且群体间存在一定基因流。(3)分子方差分析(AMOVA)结果显示遗传变异主要存在于居群内(63%),居群间遗传变异为37%。Mantel检验表明陕西唐棣居群地理距离与遗传距离之间无明显相关性(r = 0.192,P = 0.220)。研究表明,AFLP分子标记可以准确、有效地用于唐棣遗传多样性分析;唐棣遗传变异主要来源于居群内,居群间的基因交流有限;陕西野生唐棣遗传多样性水平较低,但部分居群的遗传多样性较高。该研究结果可为野生唐棣资源的保护、良种选育和开发利用提供理论依据。     

硬核资源遗传多样性的AFLP分析

为了解云南省硬核[Scleropyrum wallichianum（Wight et Arn.）Arn.]的遗传多样性,采用AFLP标记分析了7个居群84份种质材料的遗传变异。结果表明,从64对引物组合中挑选出多态性较好的引物8对,共扩增出1 728条带,其中多态性条带1 388条,多态性百分率为80.14%。硬核在物种水平的多样性指数分别为Na=1.416,Ne=1.179,H=0.137,I=0.225,在居群水平上分别为H=0.111,I=0.175;在遗传相似性系数为0.52时,这些种质材料可分为3组,其中易武居群具有丰富的遗传变异,大部分的遗传变异存在于居群内,而在0.05置信区间内居群间遗传变异仅为11.5%;居群间的遗传距离和地理距离无显著相关性（r=0.0323,P=0.5820）。因此,硬核资源可采用就地和迁地保护策略,以增加其遗传多样性。     

葫芦苏铁遗传多样性的等位酶分析

采用等位酶技术,分析了葫芦苏铁5个居群的遗传多样性。分析6个酶系统,共获得了13个基因位点, 结果表明:葫芦苏铁具有较高水平的遗传变异性,多态位点百分率(P)为56．9％,等位基因平均数A=1.62,等 位基因多样性指数Ho=0.105,He=0．164,居群杂合体过量的位点为50％。居群遗传结构分析表明,大部分 遗传变异(93．6％)存在于居群内(FST=0．064),居群间分化程度甚微。根据葫芦苏铁的居群遗传结构式样并 结合相关研究,提出了就地保护所有居群,迁地保护从东一、王下和水田三个大居群取样的保护策略。     

粗山羊草居群间遗传分化及多样性的SSR分析

选用分布在粗山羊草14条染色体上的32对SSR引物,对来自中国河南、陕西、新疆和中东地区共147份粗山羊草材料进行遗传分化及多样性分析,结果表明在26个多态性位点中,等位基因数平均为4.15,Ne i基因多样性指数(He)平均为0.243,多态性信息含量指数(PIC)平均为0.226;居群间遗传变异差异明显,中东粗山羊草居群具有丰富的遗传变异(He=0.607,PIC=0.551),而来自陕西和河南的粗山羊草资源遗传多样性较低(He=0.055,PIC=0.047)和(He=0.024,PIC=0.021)。AMOVA分子变异分析显示,居群间遗传变异占总变异的52%,达到显著水平;河南粗山羊草和陕西粗山羊草间发生了一定的遗传分化(Fst=0.210),为研究中国粗山羊草资源的起源与分化问题提供了有用的信息与证据。     

濒危植物版纳青梅保护遗传学研究初报

运用20个10碱基随机引物,对中国龙脑香科(Dipterocarpaceae)特有的珍稀濒危植物版纳青梅(Vatica guangxiensis X. L. Mo)进行了RAPD多态性分析.3个自然居群和1 个迁地保护居群(分布于云南和广西)共扩增出231个位点,多态位点所占比例(PPB)为53.68%;观察等位基因数na=1.536*!8,有效等位基因数ne=1.287*!8,Nei基因多样性指数h为0.168*!6,居群内的遗传多样性水平较低.基于AMOVA和POPGENE的结果均表明居群内的遗传变异大于居群间的遗传变异.居群内的遗传变异为55.09%,居群间的变异为44.91% (AMOVA);基因分化系数Gst为0.374*!6 (POPGENE),表明居群间存在高水平的遗传分化.研究结果对该濒危植物的保护有重要意义.考虑到低水平的遗传多样性和高水平的居群分化,通过居群间种子和幼苗的交换来促进基因流是可行的保护方案.迁地保护居群(ML)不具最高的遗传多样性,表明为了保护此濒危物种的全部遗传变异,需要进一步采集更多个体补充到迁地保护居群中.     

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     

Similar aerosol emission rates and viral loads in upper respiratory tracts for COVID-19 patients with Delta and Omicron variant infection

Highlights
1 Aerosol emission rates of Delta or Omicron patients were similar.
2 Viral loads in upper respiratory tract of Alpha, Delta and Omicron patients were similar.
3 Viral loads in upper respiratory tract of vaccinated or unvaccinated Delta patients had no difference.     

Recombinant human interferon-α1b inhibits SARS-CoV-2 better than interferon-α2b in vitro

Highlights
1) A comprehensive evaluation method for anti-SARS-CoV-2 drugs was established based on RT-qPCR, TCID₅₀ method, and immunofluorescence.
2) A significant antiviral effect of rHuIFN-α1b was shown with EC₅₀=0.12 IU/mL in Vero cells and EC₅₀=0.52 IU/mL in Calu-3 cells, which was better than rHuIFN-α2b (EC₅₀=0.25 IU/mL in Vero cells and EC₅₀=2.48 IU/mL in Calu-3 cells).
3) rHuIFN-α1b has a good potential in the application of anti-COVID-19 therapy.     

Continued antigenic variation of highly pathogenic avian influenza A (H7N9) virus in laying hens in China, 2020–2021

Highlights
1. 13 strains of H7N9 viruses from laying hens in 2020 and 2021 were identified.
2. H7N9 viruses in China comprised at least 11 genotypes.
3. H7N9 viruses are high pathogenic in chickens, not in ducks.
4. The most H7N9 viruses cross-reacted poorly with H7-Re3 antiserum.
5. The H7-Re3 vaccine was unable to prevent H7N9 infection.