榆树黄化病植原体的分子检测与鉴定   总被引：5，自引：0，他引：5  

ZHU Tian-sheng  潘一展  CUI Ting-tao  高瑞  LI Xiang-dong  朱水芳 《植物病理学报》2008,38(4):401-406

 利用植原体16SrRNA基因的通用引物R16rrLF2/R16mR1和R16F2n/R16R2对山东泰山上发生的榆树(Ulmus parvifolia)黄化病感病植株总DNA进行巢式PCR扩增,得到了约1.2kb的特异性片段,从分子水平证实了榆树黄化病的病原(EY-China)为植原体。将扩增到的片段测序,并进行一致性和系统进化树分析。结果表明,该分离物属于植原体榆树黄化组(Candidatus Phytoplasma ulmi),与该组成员16SrRNA序列的一致性均在98.2%以上,其中与16SrV-B亚组中的纸桑丛枝(Paper mulberry wiches'-broom)和枣疯病(Jujube witches'-broom)植原体一致性最高,达到99.4%,在系统进化树中与该亚组成员聚类到同一个分支,说明该分离物属于植原体16SrV-B亚组。本研究首次对在中国引致榆树黄化病的植原体进行了分子检测,并通过核酸序列分析将其鉴定到亚组水平。  相似文献   

Analysis of Spanish populations of Ophiostoma ulmi and O. novo-ulmi using phenotypic characteristics and RAPD markers     

A. Solla  M. C. Dacasa  C. Nasmith  M. Hubbes  L. Gil 《Plant pathology》2008,57(1):33-44

One hundred and six isolates of the Dutch elm disease (DED) fungi Ophiostoma ulmi and Ophiostoma novo-ulmi were collected from elm trees with symptoms in 15 regions of Spain. Isolates were compared with eight reference strains belonging to O. ulmi and the two subspecies of O. novo-ulmi. The purpose of this study was to assign Spanish isolates to species and subspecies of the DED fungi and to analyse the genetic variability within the Spanish populations of these pathogens. Isolates were examined for their growth rates, colony morphologies and fertility responses and by using random amplified polymorphic DNA (RAPD) markers. Six isolates were identified as O. ulmi , 16 as O. novo-ulmi ssp. novo-ulmi and 78 as O. novo-ulmi ssp. americana . Nei's and Shannon's diversity indices and the upgma dendrogram from RAPD profiles indicated a high level of variation among isolates, probably reflecting post-epidemic status of DED in Spain. Although most isolates were separated into three major clusters representing the three taxa of DED fungi in the RAPD analysis, two isolates from central Spain clustered between O. novo-ulmi ssp. americana and O. novo-ulmi ssp. novo-ulmi , and four isolates from Mallorca clustered between O. ulmi and the group representing O. novo-ulmi ssp. novo-ulmi . Mating tests conducted with these isolates revealed a variety of fertility responses. The novel combinations between molecular profile and fertility reaction suggest that three isolates from Mallorca may be interspecific hybrids of the DED fungi.  相似文献   

Elm tree bark extract inhibits HepG2 hepatic cancer cell growth via pro-apoptotic activity     

Tae Myoung Kim  Sang-Kyung Shin  Tae-Wang Kim  So-Young Youm  Dae Joong Kim  Byeongwoo Ahn 《Journal of veterinary science (Suw?n-si, Korea)》2012,13(1):7-13

Control of inflammation is widely accepted as an important strategy for cancer chemoprevention. Anti-inflammatory effects of bark extracts of elm tree (BEE) have been amply reported. Therefore, BEE may be a good candidate cancer chemopreventive agent. Considering the high incidence of hepatic cancer and limited therapeutic approaches for treating this disease, it is important to develop liver cancer-specific chemopreventive agents. To evaluate the chemopreventive potential of BEE, we investigated the growth inhibition effect of BEE on the HepG2 human hepatocellular carcinoma cell line. We performed a cell counting kit-8 assay to determine cell viability, and 4,6-diamino-2-phenylindole staining and flow cytometry to measure apoptotic cell death. Finally, the expression levels of pro- and anti-apoptotic proteins were measured. BEE inhibited the growth of HepG2 cells and induced apoptosis in a dose-dependent manner. Pro-apoptotic activity was promoted via the mitochondrial pathway of apoptosis, as demonstrated by the activation of pro-apoptotic proteins Bax, caspase-9, caspase-3, and poly (ADP-ribose) polymerase as well as the down-regulation of the anti-apoptotic protein Bcl-2. These results suggest that BEE may have potential use in hepatic cancer chemoprevention by suppressing cancer cell growth via pro-apoptotic activity.  相似文献   

The first record of Botryodiplodia canker in Poland     

Czes&#x;aw Bartnik  Piotr Boro&#x;  Jakub Michalcewicz  Micha&#x; Ciach 《Forest Pathology》2019,49(4)

This study describes the first observation of Botryodiplodia canker in the Western Carpathians in south‐eastern Poland caused by Botryodiplodia hypodermia (Sacc.) Petr. (syn. Sphaeropsis hypodermia, S. ulmicola). The canker occurred on an approximately 17‐year‐old Ulmus glabra sapling in a mixed conifer/deciduous stand with elm trees severely damaged by Dutch elm disease. This paper describes disease symptoms and provides information on the macro‐ and micromorphology of the fungus isolated from the cankered tissues. The results of BLAST search using DNA sequences obtained for our cultures and subsequent phylogenetic positioning of the fungus among closely related Botryosphaeriaceae indicate that the species is much more closely related to Phaeobotryon than to the other Botryodiplodia or Sphaeropsis species. Moreover, a total of 16 polymorphisms within the ITS region were detected between S. ulmicola associated with Botryodiplodia canker in North America and B. hypodermia associated with the canker observed in Poland. Thus, the “European” variant of “Sphaeropsis” ulmicola can now be easily identified with our barcode sequences. The Botryodiplodia canker is much less prevalent in Europe than in North America. Differences in virulence of “American” and “European” linages and differences in susceptibility of various elm species may be the reason for the higher prevalence of the disease in North America.  相似文献   

Detection and Indentification of European Stone Fruit Yellows and Other Phytoplasmas in Wild Plants in the Surroundings of Apricot Chlorotic Leaf Roll-affected Orchards in Southern France     

W. Jarausch  B. Jarausch-Wehrheim  J.L. Danet  J.M. Broquaire  F. Dosba  C. Saillard  M. Garnier 《European journal of plant pathology / European Foundation for Plant Pathology》2001,107(2):209-217

Between 1994 and 1998 a field study was conducted to identify plant hosts of the European stone fruit yellows (ESFY) phytoplasma in two apricot growing regions in southern and southwestern France where the incidence of apricot chlorotic leaf roll was high. A total of 431 samples from 51 different plant species were tested for the presence of phytoplasmas by PCR using universal and ESFY-specific primers. ESFY phytoplasma was detected in six different wild growing Prunus species exhibiting typical ESFY symptoms as well as in symptomless dog rose bushes (Rosa canina), ash trees (Fraxinus excelsior) and a declining hackberry (Celtis australis). The possible role of these plant species in the spread of ESFY phytoplasma is discussed. PCR-RFLP analysis of ribosomal DNA amplified with the universal primers was carried out to characterize the other phytoplasmas found. Thus, elm yellows phytoplasma, alder yellows phytoplasma and rubus stunt phytoplasma were detected in declining European field elm trees (Ulmus carpinifolia Gled), in declining European alder trees (Alnus glutinosa) and in proliferating Rubus spp. respectively. The presence of rubus stunt phytoplasma in great mallow (Malva sylvestris) and dog rose was demonstrated for the first time. Furthermore, the stolbur phytoplasma was detected in proliferating field bindweed (Convolvulus arvensis) and a previously undescribed phytoplasma type was detected in red dogwood (Cornus sanguinea). According to the 16S rDNA-RFLP pattern this new phytoplasma belongs to the stolbur phytoplasmas group.  相似文献   

Nucleotide Sequence of Citrus Tristeza Virus Seedling Yellows Isolate     

Cede SUASTIKA  Tomohide NATSUAKI  Hirotsugu TERUI  Takeshi KANO  Hiroyuki IEKI  Seiichi OKUDA 《Journal of General Plant Pathology》2001,67(1):73-77

The complete nucleotide sequence of a seedling-yellows-inducing isolate NUagA of Citrus tristeza virus (CTV) was determined. It consisted of 19302 nucleotides and contained 12 open reading frames (ORF) organized identically to those of previously sequenced isolates. This genome is the largest among the CTV genome sequenced so far ; it is 6 nucleotides (nt), 76 nt, 43 nt, and 53 nt longer than that of T36 (quick decline, Florida), VT (seedling yellows, Israel), T385 (mild, Spain), and SY568 (stem pitting, California), respectively. Sequence comparison of NUagA and the other isolates revealed approximately 90% identities throughout the 3′ half of the genome. The 5′ half of the genome was only about 70% identical to that of T36 but still high at about 90% to those of VT, SY568, and T385. Comparison of amino acid sequences on ORF1a encoding polyproteins, the most variable region, reflects the CTV isolate relationship ; NUagA is closely related to VT, SY568, and T385, but distantly related to T36. Received 29 May 2000/ Accepted in revised form 16 November 2000  相似文献   

The incubation period of beet yellowing viruses in sugar-beet under field conditions     

W. Van Der Werf  C. Kempenaar  D. Peters 《European journal of plant pathology / European Foundation for Plant Pathology》1989,95(5):241-258

In three years field trials, the incubation period, i.e. the time between infection and the appearance of symptoms, of beet yellows virus (BYV) and beet mild yellowing virus (BMYV) increased with later infection during the growing season. The incubation period of BYV, a closterovirus, increased from 3 weeks in young plants infected before canopy closure, to 9 weeks in old plants infected in August. The incubation period of BMYV, a luteovirus, increased from 4 to 5 weeks in young plants to 9 weeks in old plants. Symptoms were observed c. one week earlier on the inoculated leaves than on those infected systemically, except on young BYV-infected plants. On these plants, symptoms developed in 3 weeks on both leaf types.The incubation period decreased at increasing temperature, a fixed temperature sum being required for the development of symptoms on plants of a certain age. This temperature sum increased with plant age. Symptom development was related to leaf growth; the systemic symptoms appeared after the infected leaves attained their final size. Young, expanding leaves did not show symptoms. Thus the development of symptoms seems to be related to physiological conditions occurring only in full-grown leaves. A low rate of leaf expansion may constitute the underlying reason for the long incubation period of virus symptoms in old plants and at low temperatures.The incubation period was not substantially affected by: (1) the number ofMyzus persicae used to inoculate the plants, (2) the number of leaves inoculated, (3) the development stage of the inoculated leaf and (4) the source plant of BMYV, beet or shepherd's-purse,Capsella bursapastoris. The incubation period can be used to obtain rough estimates of the infection-date of individual plants, given the date on which symptoms appear.Samenvatting De incubatieperiode van het bietevergelingsvirus, BYV, en het zwakke-bietevergelings-virus, BMYV, nam toe naarmate suikerbieteplanten later in het seizoen geïnfecteerd werden. Jonge planten ontwikkelden BYV-symptomen na ongeveer 3 weken terwijl na gewassluiting de incubatieperiode geleidelijk toenam tot 9 weken. De incubatieperiode van BMYV nam toe van 4 à 5 weken na inoculatie in juni tot 9 weken na inoculatie in augustus. Geïnoculeerde bladeren ontwikkelden ongeveer een week eerder symptomen dan de systemisch geïnfecteerde bladeren, behalve bij jonge planten, geïnfecteerd met BYV, waar de symptomen zich op beide typen bladeren tegelijkertijd ontwikkelden.De incubatieperiode nam bij hogere temperatuur af en, afhankelijk van de leeftijd van de plant (aantal bladeren) was een bepaalde temperatuursom nodig voor de ontwikkeling van symptomen. Deze temperatuursom nam toe met de ouderdom van de plant. Van alle systemisch besmette bladeren, vertoonden de oudste, welke juist verschenen op het moment dat de plant werd geïnfecteerd, als eerste symptomen. Dit gebeurde zodra of kort nadat ze hun uiteindelijke grootte hadden bereikt. Groeiende bladeren vertoonden nooit vergelingssymptomen. De trage bladexpansie in oude planten en bij lage temperaturen is een mogelijke oorzaak van de lange incubatieperiode aan het einde van het seizoen.De incubatieperiode werd niet duidelijk beïnvloed door inoculatieomstandigheden, zoals (1) het aantal groene perzikluizen,Myzus persicae, dat werd gebruikt voor inoculatie, (2) het aantal geïnoculeerde bladeren, (3) de ouderdom van het geïnoculeerde blad, (4) de bronplant van BMYV, biet of herderstasje, of (5) de vector species. Omdat de incubatieperiode niet in belangrijke mate afhankelijk is van deze factoren kan bij kennis van de datum waarop symptomen verschenen de infectiedatum worden bepaald op basis van de incubatieperiode.  相似文献   

糖和氮对白榆组织培养新梢生根的影响   总被引：3，自引：0，他引：3  

李天珍  李保堂  王笑然 《山西林业科技》2001,(4):9-13

研究糖和无机氮源对白榆组培新梢不定根形成的影响,结果表明,含有高浓度蔗糖的培养基比低浓度蔗糖的培养基新梢生根率高.新梢对糖的这种反应与糖代谢和物理渗透都有关,用甘露作为渗透代替剂在低浓度蔗糖存在下无作用,当蔗糖浓度达到一定程度时(86.65 mmol·L-1)能影响新梢的生根率.在培养基中分别加入NO-3或NH+4作为唯一氮源,或是在MS培养基中加入NO-3/NH+4比率为标准的混合氮源,在测试范围(0 mmol·L-1～120 mmol·L-1)内均降低新梢的生根率,三者对生根的抑制作用依次为NH+4>NO-3+NH+4-N>NO-3-N.NO-3/NH+4比率与生根之间呈现直线正相关.糖/氮比值高有利于生根.插穗中碳、氮的绝对量及碳/氮比率可作为白榆新梢生根的指标.  相似文献   

瓜类蚜传黄化病毒在南疆的检测及系统进化     

麦麦提艾力·阿卜杜纳斯尔  杨渡  韩盛  温且木·阿布列孜  玉山江·麦麦提 《中国蔬菜》2020,1(7):38-44

2019年从南疆7个县/市采集表现瓜类蚜传黄化病毒(Cucurbit aphid-borne yellows virus,CABYV)侵染典型特征的47份甜瓜叶片样品,通过RT-PCR进行CABYV的检测,从县/市各选出1份代表性样本,进行特异性片段的克隆、测序,以及核苷酸多样性、蛋白序列和系统发育分析。结果显示,28份样本呈现CABYV阳性,检出率为59.57%,巴楚县、阿克苏市、莎车县、伽师县、疏勒县、疏附县、洛浦县的检出率分别为80.00%、28.57%、83.33%、60.00%、37.50%、71.42%、66.67%。克隆测序获得了707 bp的核酸序列,核苷酸多样性值在0.012～0.018之间,所有序列均具有2个开放阅读框(ORF)。ORF1编码199个氨基酸的外壳蛋白(CP),各县/市的序列相似性为99.07%。ORF2编码191个氨基酸的运动蛋白(MP),各县/市的序列相似性为98.80%。基于CP和MP序列构建的系统发育树表明,各县/市得到的所有CP和MP均聚在亚洲分支。CABYV在南疆甜瓜主产区普遍发生,且不同区域核苷酸变异很低,这些地区的CABYV与中国及日本分离物的亲缘关系较近,而与欧洲及中国台湾分离物的亲缘关系较远。  相似文献   

Selective transmission of the seedling yellows-type genotypic variants of Citrus tristeza virus by Aphis gossypii in northern Iran     

Saeedeh Pourhamedi  Ali Barzegar  Heshmatollah Rahimian 《Plant pathology》2020,69(4):783-793

Citrus tristeza virus (CTV) has existed in northern Iran for more than five decades. The long-time interaction of different virus genotypes with Aphis gossypii, as the only aphid vector of CTV in northern Iran, has led to the emergence of highly virulent subpopulations, among others, in the established foci. Here, we studied the population structure of the originally established CTV isolates present in Satsuma mandarin (Citrus unshiu) trees imported from Japan, and subisolates thereof, formed following experimental transmission by A. gossypii, as well as those evolved through natural transmission by this aphid species in the groves. Symptoms of the naturally spread and the experimentally aphid-transmitted isolates were similar to those of the Satsuma CTV source isolates for all indicator plants except for sour orange (Citrus aurantium) and grapefruit (Citrus paradisi), with the aphid-transmitted isolates additionally inducing severe seedling yellows and stunting in these two indicators. Studies on the population heterogeneity of these isolates through comparison of their single-strand conformational polymorphism profiles and nucleotide sequences of the 25 kDa capsid protein gene from the predominant haplotypes, and dot-blot hybridization signals, revealed the presence of two major T36- and SY568- (or NUagA-) like genotypes along with a minor poorly characterized one in the originally infected Satsuma trees; in contrast, only a certain genomic variant having the highest similarity to the isolate SY568 (and NUagA) was predominant both in the naturally infected trees and in those infected experimentally by A. gossypii. It seems that transmission by A. gossypii to sweet orange (Citrus sinensis) has led to the preponderance of the CTV genomic variants inducing severe seedling yellows in northern Iran.  相似文献