小麦-簇毛麦新种质山农05078的鉴定(简报)

簇毛麦（Dasypyrum villosum,VV,2n=14）属禾本科小麦族小麦亚族簇毛麦属,分蘖力比较强,多花,籽粒蛋白质含量高,耐旱,抗寒性好,高抗锈病、全蚀病和白粉病。硬簇麦（AABBVV,2n=42）是利用硬粒小麦和簇毛麦杂交人工合成的双二倍体,保留了簇毛麦的优良性状和特点,是进行小麦遗传改良的优良中间材料。人工合成小麦Am3（AABBDD,2n=42）是利用波斯小麦与粗山羊草杂交后染色体加倍而形成的双二倍体,但它所具有的A、B、D染色体组可能与经过多年分化的普通小麦所含的A、B、D染色体组不同,     

簇毛麦及其与普通小麦杂种双二倍体的C一分带分析

本研究对簇毛麦(Haynaldia villosa),普通小麦“农大146" (Tritieum aestivum）及其产生的双 二倍体进行了C一分带分析,结果表明：(1) 7对簇毛麦染色体均可显示清晰的带型、根据带型可以把各 簇毛麦染色体与小麦染色体相互区别开来; (2)普通小麦一簇毛麦双二倍体的染色体数变幅在”-56 之间,其中2n - 5‘的个体占,7.680%     

簇毛麦和硬粒小麦-簇毛麦双二倍体的染色体N-分带

利用染色体N-分带技术可鉴别簇毛麦(Haynaldia villosa)V染色体组的所有7条染色林,并且可与硬粒小麦(Triticum durum)A、B染色体组的14条染色体相区别。利用染色体N-分带技术,一个硬粒小麦-簇毛麦双二倍体得到了进一步证实。     

利用AABBDDDD八倍体培育小麦-簇毛麦二体附加系的研究

对普通小麦（Triticumaestivum）-节节麦（Aegilopssquarrosa）八倍体（2n=8x=56,AABBDDDD）与硬粒小麦（Triticumdurum）-簇毛麦（Haynaldiavillosa）六倍体（2n=6x＝42,AABBVV）杂交后,将所得七倍体杂种（AABBDDV）进行连续自交,在F4代中利用C-分带鉴定出可能的簇毛麦6V二体附加系95－7和2V二体附加系26－7,其花粉母细胞染色体在减数分裂中期I的配对构型分别为0.14I＋20．42＋1．5和0．10I＋20．07＋1.82;进一步将95－7和26－7的基因组DNA用EcoRI酶切,分别用小麦族第6部分同源群短臂探针Psr113和第2部分同源群长臂探针BCD240进行Southern杂交,结果显示具有簇毛麦的特异杂交带,进一步确证了95－7和26－7分别是普通小麦-簇毛麦6V和2V二体附加系。     

簇毛麦NBS类R基因相关序列的分子标记开发及其染色体定位

小麦近缘种簇毛麦携带许多尚未克隆的抗病(R)基因。NBS-LRR类型的R基因占已克隆植物R基因的绝大多数,因此,本研究根据NBS-LRR类型R基因的保守序列设计引物,从簇毛麦基因组DNA和cDNA中扩增获得23条相关序列。基于其中5条抗病基因同源序列(RGAs)H-56/d6、H-66/b2和CDS40设计引物,对小麦、簇毛麦、硬-簇双二倍体及其杂种以及已知携带个别簇毛麦染色体或染色体臂的小麦材料进一步进行PCR扩增,结果表明:3对引物均可对簇毛麦、硬-簇双二倍体进行特异扩增;同时,源于序列H-66/b2的引物可对1VL和6VL染色体臂进行特异扩增;源于序列CDS40的引物可在同时携带1VL和2VS或同时携带2VS和4V的小麦材料以及具有6VL的小麦材料中特异扩增,而H-56/d6的引物在携带1VL、2VS、4V和6V染色体臂或染色体的小麦背景中都不能获得目的片段的扩增。这些结果不仅为外源染色体臂在小麦背景中的追踪与鉴定提供了新的分子标记,而且这些标记还与外源染色体或染色体臂上的抗病基因或抗病基因同源物紧密连锁或共分离。     

簇毛麦染色体组特异性RAPD标记的筛选、定位和应用

以普通小麦中国春、中国春－簇毛麦二体附加系以及不同来源的簇毛麦为材料,用100个10碱基随机引物进行RAPD扩增。引物OPF02能在不同来源的簇毛麦及所有中国春－簇毛麦二体附加系中扩增出一条长约750bp的片段OPF02 750。普通小麦和硬粒小麦不能扩增出该片段。因此,OPF02 750为分布于簇毛麦所有染色体上的一个簇毛麦染色体组特异片段。用引物OPF02对普通小麦－簇毛麦双二倍体、硬粒小麦－簇毛麦双二倍体以及几个普通小麦的簇毛麦二体代换系、二体附加系进行检测,发现NAU302已经丢失了其所附加的簇毛麦3V染色体。     

节节麦-簇毛麦属间杂种的形态学和细胞遗传学研究

通过远缘杂交,结合杂种幼胚离体培养,获得了节节麦（Aegilops tauschii,2n=14,DD）和簇毛麦（Dasypyrum villosum,2n=14,VV）的属间杂种F1。对杂种F1花粉母细胞减数(PMC)分裂中期Ⅰ (MⅠ)染色体配对行为进行观察发现,“节节麦×簇毛麦”杂种F1平均每PMC有1.25个棒状二价体, 染色体的平均构型为2n=14=11.49Ⅰ+1.25Ⅱ (Xta=1.25), 大部分被观察的细胞出现1～5个二价体, 表明节节麦D染色体与簇毛麦V染色体间具有相对较高的部分同源配对, D和V染色体之间存在一定的部分同源性。F1植株高度自交不育,经染色体加倍处理后能够自交结实。Abstract: ‘Aegilops tauschii×Dasypyrum villosum’ F1 hybrids were obtained by the combination of hybridization and embryo culture in vitro. Chromosome pairing behavior in meiosis of the hybrid F1 was carried out. Results showed that in an average , 1.25 rod bivalents were observed in one PMC, meiotic configuration was 2n=14=11.49Ⅰ+1.25Ⅱ(Xta=1.25) and most of PMCs possessed 1～5(rod) bivalens, indicating that the relatively high homeology was detected between the D genome of Ae.tauschii and the V genome of D.villosum. The morphological differences between F1 hybrids and their parents were significant. F1 plants were highly self-sterile, but partially self-fertile after treated by chromosome doubling technique.     

小麦-簇毛麦种质系‘山农030713＇的细胞学和SSR鉴定

利用形态学、细胞学以及SSR标记技术对从硬簇麦和Am3的杂种后代中选育的种质系‘山农030713＇进行了鉴定,结果表明：种质系‘山农030713＇大田生长整齐一致,农艺性状较好,且对白粉病免疫;其根尖细胞染色体数目为2n=42,花粉母细胞减数分裂中期Ⅰ（PMC M Ⅰ）染色体构型为2n=21Ⅱ;它与普通小麦的杂种F1PMC MⅠ多数细胞中形成21个二价体,且常有四价体出现,可能伴有染色体的结构变异;SSR分析证明‘山农030713＇基本染色体组成为AABBDD,引物Xgwm99-1A在‘山农030713＇中扩增出簇毛麦的特异带,表明‘山农030713＇中有来自于簇毛麦的遗传物质,此特异带可作为识别‘山农030713＇的SSR标记.综合形态学、细胞学和SSR分析结果推测,‘山农030713＇可能是一个小麦-簇毛麦易位系.     

利用小麦微卫星引物建立簇毛麦染色体组特异性标记

选位于普通小麦1A-7A、1B-7B、1D-7D染色体上的102对微卫星引物对多年生簇毛麦、二倍体簇毛麦、小麦-簇毛麦双二倍体与后代和普通小麦中国春、R25、R111、MY11进行了PCR扩增, 发现引物对Xgwm301可以在含簇毛麦染色体的材料中扩出一条长415 bp的特异片段(命名为Xgwm301/415), 而所有供试小麦均未扩出此片段。进而用一套中国春-二倍体簇毛麦附加系来进行扩增, 发现1V-7V染色体均可以扩出该片段, 说明该片段为簇毛麦1V-7V染色体所共有。因此, Xgwm301/415是簇毛麦染色体组上的一个特异片段, 可以用来快速跟踪检测导入到普通小麦背景中的簇毛麦染色体。     

小麦-簇毛麦种质系'山农030713'的细胞学和SSR鉴定

利用形态学、细胞学以及SSR标记技术对从硬簇麦和Am 3的杂种后代中选育的种质系‘山农030713’进行了鉴定,结果表明:种质系‘山农030713’大田生长整齐一致,农艺性状较好,且对白粉病免疫;其根尖细胞染色体数目为2n=42,花粉母细胞减数分裂中期Ⅰ(PM C MⅠ)染色体构型为2n=21Ⅱ;它与普通小麦的杂种F1PM C MⅠ多数细胞中形成21个二价体,且常有四价体出现,可能伴有染色体的结构变异;SSR分析证明‘山农030713’基本染色体组成为AABBDD,引物X gwm 99-1A在‘山农030713’中扩增出簇毛麦的特异带,表明‘山农030713’中有来自于簇毛麦的遗传物质,此特异带可作为识别‘山农030713’的SSR标记.综合形态学、细胞学和SSR分析结果推测,‘山农030713’可能是一个小麦-簇毛麦易位系.     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.