二倍体石蒜在安徽发现

本文以根尖细胞为材料,观察了石蒜Lycoris radiata(L′Her．)Herb．三个不同居群植物的染色体数目和核型,发现石蒜为一复合体,包括两种不同类型：(1)三倍体类型,主要包括一群以鳞茎无性繁殖的园艺栽培植株,其染色体数目和核型为2n＝33=33t(st),属“4A”核型,且极其稳定。(2)二倍体类型,主要包括一群野生植株,变异较大,我们发现有下列几种情况：一是芜湖产石蒜(L．radiata)的野生材料,其染色体数目和核型为2n=21+1B=1m+12st+8t+1B,属“3A”核型,在石蒜种内迄今未见有类似报道;另一是黄山产野生材料,观察到两个细胞型,绝大多数细胞为2n=22＝12st+1Ot,极个别细胞出现2n＝22+1B=6st+14t+2T+1B的情况,均属“4A”核型。芜湖和黄山野生材料的染色体数目和核型均为首次报道。石蒜(L．radiata)的二倍体类群也是首次在安徽发现。     

六个石蒜居群的核型及四倍体石蒜的发现

染色体与核型的变化是植物系统发育和进化的一个重要方面。石蒜属Lycoris植物特别是石蒜L.radiata在染色体数目和核型上存在较大的变异。通过对不同居群的石蒜核型研究,可以为石蒜和石蒜属植物的核型演化及演化机制提供一些重要的基础资料。本文对分布于中国安徽省和浙江省的6个石蒜居群进行了细胞学研究。结果表明,6个石蒜居群的染色体数目和核型分别为：霍山居群2n=44=28st＋8t＋8T,2n=22=6st＋12t＋4T;黄山居群2n=22=22t,2n=22=18st＋4t,2n=21=12st＋7t＋2T;滁州居群2n=33=33t;马鞍山居群2n=33=18st＋15T,2n=25=1m＋20st＋2t＋2T;宣城居群2n=22=20st＋2T,2n=21=1m＋20st;杭州居群2n=22=12st＋4t＋6T,2n=21=18st＋3t。其中,部分居群的核型类型为首次报道;并首次发现了四倍体的石蒜居群。此外,对石蒜的核型进化和多倍体起源进行了初步探讨。     

安徽产石蒜两个居群的核型研究

观察了石蒜(Lycoris radinta)两个不同居群植物的染色体数目和核型,发现野生石蒜在一个植株的不同根尖细胞里,存在两种倍性的细胞,如生于宣城敬亭山的居群既有正常三倍体：2n=33=18st 15T,属于“4A”核型;还有异常二倍体：2n=20 1B=2st 18T 1B,属于“4B”核型;生于芜湖的居群核型为：2n=20 1B=lm 9T 4t 6st 1B和2n=20 1B=1M 9T 10st 1B,属于“3B”和“3C”核型。     

黄精属5种植物的核型研究

本文报道了安徽省黄精属Polygonatum Mill．5种植物的染色体数目和核型。玉竹P. odoratum (Mill.)Druce黄山材料2n=16=10m(3sc)+6sm,滁县琅琊山材料2n=18=10m(1sc) +2sm+6st(2sc),二者均属2B核型． 长梗黄精P．filipes Mirr. 黄山材料2n=22=8m+8sm(2sc)+6st,属3B核型,安徽繁昌材料2n=14=10m+4sm和2n=16=8m +4sm+4st,二者均属2B核型。多花黄精(P.cyrtonema Hua)安徽黄山材料2n=20=8m+6sm+6st和2n=22=6m+8sm +4st+4t,二者均属3B核型,安徽滁县琅琊山材料2n=18=8m(2sc)+6sm+4st,属2B核型。长苞黄精(P．desoulayi kom．) 2n=22=10m(2sc)+6sm(1sc)+6st,属3B核型;轮叶黄精(P．verticillatum(L．)All．)2n=18=2m+2sm+10st+2t+2T和2n=24=6m+4sm+12st+2T,二者均属3B核型。其中玉竹2n=16,长梗黄精2n=14和2n=22,长苞黄精2n=22,轮叶黄精2n=18的染色体数目和核型均为首次报道。     

中国山芹属的核型演化及地理分布的研究

本文报道了山芹属Ostericum 5种1变种13个居群的核型,其中4种为首次报道。其核型如下：隔山香 O．citriodorum 广东宝安的居群,2n=22=16m+6sm;江西鹰潭的居群,2n=22=14m+6sm+2st;华东山芹 O．huadongensis本所药物园居群,2n=22=16m+6sm;安徽广德的居群,2n=22=16m+4sm+2sm(SAT);绿花山芹 O．viridiflorum内蒙古额右旗的居群,2n=22=18m+4sm;黑龙江双鸭山居群,2n=22=18m+2sm+2st(SAT);山芹 O．sieboldii 辽宁庄河居群,2n=22=4sm+16st+2st(SAT);吉林长白山居群,2n+22+2sm+20st;狭叶山芹 O. sieboldii var．praetieritum 辽宁鞍山的居群,2n=22=2sm+20st;大齿山芹 O.grosseserratum 辽宁庄河居群,2n=18=2sm+16st;江苏宜兴居群,2n=18=2sm+16st;安徽广德居群,2n=18=18st;浙江天目山居群,2n=18=18st。隔山香、华东山芹和绿花山芹具较原始的2A型,山芹和大齿山芹则具较为进化的4A型。此外,大齿山芹具有下行性的染色体基数n=9,这在整个前胡族中都具独特性。根据各居群在种分布区内的核型演化方向及现代地理分布格局并结合形态和孢粉学资料,提出本属的起源是从近缘的当归属起源地横断山区沿着东北和东南两个方向迁移扩散,演化发展形成两个现代次生分布中心,一个是东北向具温带性广布型的分布中心(东北地区),另一个是东南向具亚热带性特有种型的分布中心(华东地区),两个分布中心之间有一个分化活跃、演化最高的纽带种一大齿山芹。     

六种葱属植物核型研究

葱属粗根组和根茎组6种11个居群的染色体数目和核型的研究结果如下:A．cyathophorum: 2n=2x=16=12m+4sm(2SAT)。A．przewalskianum:西藏察雅和四川理县居群分别为2n=4x=32 =28m+4st(2SAT)and 2n=4x=32=28m+2sm+2st(2SAT)。A． polyrhizum :2n=2x=20m+8sm+ 4t(2SAT)。A．mongolicum:2n=2x=16=14m+2st(2SAT)。A.senescens:朝鲜郁陵岛和中国内蒙古 科尔沁左翼后旗居群分别为2n=4x=32=28m+2sm+2st(2SAT)and 2n=4x=32=24m+4sm+4st (2SAT)。A．tuberosum:所研究的四个居群中,山西永济居群为二倍体,2n=2x=16=14m=2st (2SAT),另三个分别来自四川的理县、汶川玉龙和成都三瓦窑的居群均为四倍体,2n=4x=32=28m +4st(2SAT)。A．przewalskianum,A．polyrhizum and A. mongolicum的核型为首次报道;并首次 在中国发现了A．tuberosum的野生二倍体居群。此外,还讨论了栽培韭的起源以及A．cyathophorum,A．przewalskianum和A. senescens种内居群间的核型分化问题。     

三倍体短葶飞蓬的发现及其在育种上的意义

对云南省野生居群的短葶飞蓬有丝分裂的细胞学特征进行观察研究。在云南省大理苍山、腾冲杨家坪的二倍体野生居群中,发现有三倍体个体的存在。苍山居群的两种核型分别为2n=2x=18=4m 10sm 4st,2n=3x=27=6m 12sm 9st;杨家坪居群的两种核型分别为2n=2x=18=6m 10sm 2st,2n=3x=27=3m 15sm 9st。通过对其生物学特性及表型的分析,认为短葶飞蓬可以采取多倍体育种方式获得更优良的品种。     

宽叶韭居群间核型研究

对宽叶韭 1 0个居群的核型进行了研究 ,结果如下 :四川武隆居群 2 n=2 x=2 2 =1 6sm+6st;四川大飞水居群 2 n=2 x=2 2 =1 6sm +4st+2 t(2 SAT) ;四川南川居群 2 n=2 x=2 2 =2 m+1 4sm+4st+2 t;四川宝兴居群 2 n=2 x=2 2 =1 4sm+6st+2 t;四川青神居群 2 n=2 x=2 2 =2 m+6sm+1 0 st+4t;四川沐川居群 2 n=2 x=2 2 =2 m+1 4sm+2 st+4t;四川屏山居群 2 n=3 x=3 3 =3 m+2 1 sm+9st;云南西双版纳居群 2 n=2 x=2 2 =1 4sm+6st+2 t(2 SAT) ;广东乳源居群 2 n=3 x=3 3 =2 1 sm+6st+6t(3 SAT) ;广西龙胜居群 2 n=3 x=3 3 =2 1 sm+6st+6t(3 SAT)。研究表明 ,除四川屏山居群、广东乳源居群、广西龙胜居群是三倍体外 ,其余均为二倍体。它们都属于 Stebbins的 3 A型。此外 ,宽叶韭的不同居群间还存在随体染色体和核型组成的多态性。本文最后讨论了宽叶韭种内居群间核型分化的原因。     

国产8种蜘蛛抱蛋属植物的核型研究

首次报道了8种蜘蛛抱蛋属植物的核型,其中6种的染色体数目为首次报道。结果如下：峨边蜘蛛抱蛋A．ebianensis,2n=2x=36=18m+2sm(2sat)十16st;盈江蜘蛛抱蛋A．yingjiangensis,2n=2x=36=14m+6sm(2sat)十16st;海南蜘蛛抱蛋A．hainanensis,2n=2x=36=20m(2sat)十14st十2t;石山蜘蛛抱蛋A．saxicola,2n=2x=36=16m十4sm(2sat)十16st;糙果蜘蛛抱蛋A．muricata,2n=2x=36=18m+2sm(2sat)十16st;啮边蜘蛛抱蛋A．marginella,2n=2x=38=22m+4sm(2sat)十12st;西林蜘蛛抱蛋A．xilin-ensis,2n=4x=76=48m(4sat)十2sm+26st;十字蜘蛛抱蛋A．cruciformis,2n=4x=76=46m(4sat)十12sm十18st。核型类型都为2C型。首次在中国发现了A．cruciformis和A．xilinensis的野生四倍体。根据外部形态性状及已有的38种植物的核型资料分析,认为该属染色体的原始基数可能为x=18,核型向对称性增强的方向演化,其主要表现在中部着丝粒染色体数目的增多,这种演化趋势似与其花部结构的进化密切相关。关键词 蜘蛛抱蛋属;染色体数目;核型;进化     

云南淡黄花百合10居群核型研究

对云南淡黄花百合 10个居群核型进行了研究 ,结果如下 :普洱居群 2n =2x =2 4 =4m(4SAT ) 8st (1SAT ) 12t;大湾居群 2n =2x =2 4 =4m (4SAT ) 4sm (1SAT ) 6st 10t ;宝山居群 2n =2x =2 4 =4m (4SAT ) 4st (1SAT ) 16t ;元阳居群 2n =2x =2 4 =4m (4SAT ) 8st(1SAT ) 12t;玉屏山居群 2n =2x =2 4 =4m (4SAT ) 4sm (1SAT ) 12st 4t;易门居群 2n =2x =2 4 =4m (4SAT ) 2sm 14st (1SAT ) 4t ;峨山居群 2n =2x =2 4 =4m (4SAT ) 2sm 14st(1SAT ) 4t;老鹰地居群 2n =2x =4m (4SAT ) 2sm 14st (1SAT ) 4t;双柏居群 2n =2x =2 4 =4m (4SAT ) 12st (1SAT ) 8t;牟定居群 2n =2x =2 4 =4m (4SAT ) 8st (1SAT ) 12t。研究表明各居群的核型都属于Stebbins的 3B型 ,不同居群间存在染色体类型和随体染色体的多型性 ,同时还发现了B染色体和 4倍体染色体数目变异 ,本文最后讨论了云南淡黄花百合种内居群间核型分化的原因。     

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     

Mink Circovirus Can Infect Minks,Foxes and Raccoon Dogs

正Dear Editor,Mink circovirus (MiCV), which is clustered in the genus Circovirus of the family Circoviridae, was first described in minks from farms in Dalian, China in 2013 (Lian et al.2014). The complete single-stranded circular genome of the virus is 1,753 nucleotides long and contains two major open reading frames (ORFs), designated ORF1 (Rep gene)and ORF2 (Cap gene)(Lian et al. 2014; Ge et al. 2018).Sequence analysis has shown that MiCV is most closely     

CypA Regulates AIP4-Mediated M1 Ubiquitination of Influenza A Virus

Cyclophilin A (CypA) is a peptidyl-prolyl cis/trans isomerase that interacts with the matrix protein (M1) of influenza A virus (IAV) and restricts virus replication by regulating the ubiquitin–proteasome-mediated degradation of M1. However,the mechanism by which CypA regulates M1 ubiquitination remains unknown. In this study, we reported that E3 ubiquitin ligase AIP4 promoted K48-linked ubiquitination of M1 at K102 and K104, and accelerated ubiquitin–proteasome-mediated degradation of M1. The recombinant IAV with mutant M1 (K102 R/K104 R) could not be rescued, suggesting that the ubiquitination of M1 at K102/K104 was essential for IAV replication. Furthermore, CypA inhibited AIP4-mediated M1 ubiquitination by impairing the interaction between AIP4 and M1. More importantly, both the mutations of M1 (K102 R/K104 R) and CypA inhibited the nuclear export of M1, indicating that CypA regulates the cellular localization of M1 via inhibition of AIP4-mediated M1 ubiquitination at K102 and K104, which results in the reduced replication of IAV.Collectively, our findings reveal a novel ubiquitination-based mechanism by which CypA regulates the replication of IAV.