Genetic Relationships among Prunus mume var. pendula Using AFLP Markers

Genetic relationships among Prunus mume var. pendula were studied by using AFLP markers. 18 accessions representing 14 cultivars ofPrunus murne var. pendula were selected from the germplasm collection at the Research Center of China Mci Flower. Seven Mse I-EcoR I AFLP primer combinations revealed 450 legible bands, and 269 of which were polymorphic markers. A similarity matrix was prepared using the simple matching coefficient of similarity and Nei‘s (72) distance coefficient. A UPGMA dendrogram demonstrated the genetic relationships of the cultivars. The information given by AFLP markers was basically consistent with the morphological classification and the evolutionary history of the morphotypes, and roughly supported the new revised classification system for Chinese Mci Cultivars. But there were still several exceptions: 1) the ‘Guhong Chuizhi‘ inserted between the ‘Tiaoxue Chuizhi‘ and the ‘Danfen Chuizhi‘; 2) the ‘Wufu Chuizhi‘ kept off the Pink Pendant Form, and the ‘Moshan Chuizhi‘ was removed from Viridiflora Pendant Form; 3) the ‘Danbi Chuizhi‘ and the ‘Shuangbi Chuizhi‘ of Viridiflora Pendant Form got together well but fell within the Pink Pendant Form.     

华山新麦草穗发芽抗性相关基因AIP2的克隆及其序列分析

为了挖掘和利用华山新麦草(Psathyrostachys huashanica,2n=14,NsNs)的优良基因,拓宽小麦穗发芽抗性基因资源,以华山新麦草为材料,采用同源克隆的方法克隆AIP2基因,利用生物信息学软件分析其基因结构及功能。结果表明,从华山新麦草中成功克隆AIP2基因,该基因的开放阅读框为840bp,编码279个氨基酸残基,结构域预测结果显示AIP2蛋白含有完整的Ring保守域,属于锌指环家族成员。AIP2的gDNA含5个外显子,4个内含子,华山新麦草AIP2氨基酸序列与感穗发芽小麦品种中优9507的AIP2氨基酸序列的相似性为84%,与中优9507相比缺失了44个氨基酸,与抗穗发芽的乌拉尔图小麦的AIP2氨基酸序列的相似性为80%,华山新麦草和乌拉尔图小麦都有氨基酸缺失,推测这些缺失的氨基酸可能与华山新麦草穗发芽抗性强有很大关系。本研究为小麦穗发芽抗性改良提供了新的候选基因。     

凡纳滨对虾6个养殖群体遗传多样性的比较分析

中国多批次引进凡纳滨对虾Litopenaeus vannamei并结合生产开展了相对独立的育苗工作,但对引进群体及引进后留种形成的本地群体的遗传变异水平缺乏了解,不利于种质管理及利用。此研究采用AFLP技术对抽查的6个养殖群体进行分析,发现进口群体具有相对较高的遗传多样性水平;养殖性能较好的东方、海星和旭明群体遗传多样性水平与进口群体相近;而乾塘群体遗传变异水平最高,推测可能是与其种质混杂有关;广益群体遗传多样性水平最低,可能已出现近交衰退。通过对各个群体间的遗传距离进行分析,为下一步根据亲缘关系的远近开展群体问杂交育种提供技术依据。     

利用抗性基因替换的方法将两个拷贝外源基因表达单元整合到枯草芽孢杆菌染色体基因组同一位点

本研究提供了一种新的整合多拷贝外源基因表达单元到枯草芽孢杆菌染色体同一位点的方法。以β-淀粉酶表达单元作为应用实例,本方法包括以下步骤：首先,构建含有一个拷贝β-淀粉酶表达单元的整合质粒pMLK83-CTBA,通过同源双交换获得单拷贝β-淀粉酶表达单元整合到枯草芽孢杆菌1A751染色体α-淀粉酶基因位点的菌株1A751[CTBA]Neo＋;然后,利用抗性基因替换质粒pVK71,将新霉素抗性基因替换为状观霉素抗性基因,得到1A751[CTBA]Neo-Spe＋;最后,整合质粒pMLK83-CTBA再以同源单交换方式整合到1A751[CTBA]Neo-Spe＋染色体,通过新霉素抗性和状观霉素抗性筛选出两个拷贝β-淀粉酶基因整合的重组菌1A751[CTBA2]Neo＋Spe＋。结果显示,利用此方法增加β-淀粉酶基因的拷贝数,能够显著和稳定地提高β-淀粉酶的表达量。     

Genetic diversity in Cynara cardunculus revealed by AFLP markers: comparison between cultivars and wild types from Sicily*

Genetic diversity in 49 plants of 16 accessions representing one wild and two cultivated taxa of Cynara cardunculus L. (wild cardoon, cultivated cardoon and globe artichoke) was investigated using amplified fragment length polymorphic (AFLP) analysis. Four pairs of primers identified a total of 264 scorable loci, 196 of which were polymorphic. The number of markers scored per primer combination ranged from 41 to 107, with an average of 66 markers per primer combination. All the primer combinations detected polymorphism. The data were used for cluster analysis and AMOVA. The clusters obtained are in agreement with the current botanical classification and the differences among the taxa were substantial. The eco‐geographical groups within wild cardoon are clearly separated in relative subclusters, and reflect the geography of the collection areas. The six clones of the four cultivated artichoke varieties were clearly separated into four subclusters, corresponding to the current classification which is based on morphological traits. The results obtained may have a direct and important bearing on plant genetic resource conservation and management and on breeding.     

水稻南方黑条矮缩病毒湖南鼎城株系S10片段的基因组序列分析

运用RT-PCR技术克隆了水稻南方黑条矮缩病毒（southern rice black-streaked dwarf virus,SRBSDV）湖南鼎城株系的基因组S10片段（SRBSDV-HuNDCS10）,并对其全序列进行了测定和生物信息学分析。结果显示,SRBSDV-HuNDC S10片段全长为1797bp（登录号：JQ337964）,含有1个ORF,编码557个氨基酸残基的衣壳蛋白,推测分子量约62.6kD,推测等电点为7.62,与已报道的广东、海南和云南分离物病毒的S10作比较,它们的核苷酸相似性分别为99.7%、99.0%和98.4%,氨基酸相似性分别为100.0%、99.5%和99.3%。对SRBSDV-HuNDCS10及部分Fijiviruses病毒对应片段在5＇URT与3＇URT存在的保守序列和互补序列进行了归纳,对其ORF编码的氨基酸序列进行了motif查找,得到该属（Fijiviruses）氨基酸序列的10个保守区段。此外,进行了糖基化位点、磷酸化位点及B细胞抗原表位预测,发现了3个可能的N端豆蔻酰基化位点,可能与病毒的侵染机制有关。     

猪D型产毒素多杀性巴氏杆菌毒素分段基因的原核表达

根据GenBank已发表的产毒素多杀性巴氏杆菌（T＋Pm）toxA基因序列（AF240778）设计1对引物,从猪源D型T＋Pm中扩增出toxA基因片段（3858 bp）,再根据toxA基因序列设计3对引物,分别扩增出ZQ（1084 bp）、ZH（1092 bp）、HM（906 bp）3个分段基因,将其克隆至原核表达载体pET32a,转入大肠杆菌BL21中进行融合表达。经SDS-PAGE和West-ern blotting检测分析,发现ZQ、HM基因的表达产物以包涵体形式存在,大小分别为75、50 kDa,ZH基因不表达。动物试验结果表明,HM重组蛋白具有良好的免疫原性、反应原性及一定的生物学活性,而ZQ重组蛋白没有免疫原性、反应原性及生物学活性。通过间接ELISA的方法检测抗毒素的阳性猪血清,结果表明,HM重组蛋白较天然蛋白具有更高的特异性。     

Genetic diversity of sulfonylurea-resistant and -susceptible Monochoria vaginalis populations in Japan

Monochoria vaginalis is one of the most serious weeds of rice fields in Asia. The species is predominantly selfing. To reveal the potential for multiple mutational events, outcrossing and gene flow in the sulfonylurea‐resistant (SU‐R) M. vaginalis populations, we investigated (i) if each SU‐R population was a single SU‐R biotype or a mixture of several SU‐R biotypes using restriction analysis or direct sequencing of acetolacatate synthase (ALS) genes and (ii) genetic diversity of SU‐R and ‐susceptible (S) populations using amplified fragment length polymorphism (AFLP) analysis. Nineteen or 20 individuals were sampled from four SU‐R and five SU‐S populations respectively. Amino acid substitutions conferring resistance in the SU‐R populations were Pro₁₉₇Ser in the ALS1 or ALS3, or Asp₃₇₆Glu in the ALS1 and each SU‐R population was composed of a single SU‐R biotype. In cluster analysis each SU‐R individual formed a cluster, whereas the individuals from a SU‐S population belonged to different clusters. Some SU‐R populations showed polymorphic AFLP loci. The results indicated that these SU‐R biotypes emerged from a single mutational event and any gene flow of SU‐R genes from adjacent populations did not occur. A low level of outcrossing and recombinations of SU‐R genes occurred within some SU‐R populations of M. vaginalis.     

含岩屑紫色土水分扩散规律

紫色土中存在的岩屑显著影响土壤水分扩散。以往研究主要集中在> 2 mm岩屑上而忽视了<2 mm岩屑的作用。因此,探讨>2 mm岩屑对紫色土水分扩散的影响基础上,明确<2 mm岩屑的作用对完善含岩屑紫色土水分扩散规律的研究具有重要的意义,从而为土壤水动力学模型的构建提供理论依据。以四川盆地紫色页岩发育的暗棕紫泥土和泥岩发育的红棕紫泥土为研究对象,设置3种岩屑粒径(0.25~2,2~5,5~10 mm)和4种岩屑含量(0,30%,50%,70%),利用水平土柱吸渗法测定含岩屑土壤湿润锋变化特征、水分扩散率D(θ)和土壤含水率θ,并拟合D(θ)、Boltzmann参数λ与θ之间的关系。结果表明:对于暗棕紫泥土,岩屑粒径为2~5 mm时,土壤湿润锋前进速率和D(θ)随岩屑含量增加呈先增加后降低再增加的趋势;岩屑粒径为0.25~2,5~10 mm时,土壤湿润锋前进速率和D(θ)随岩屑含量增加逐渐增加。对于红棕紫泥土,岩屑粒径为2~5,5~10 mm,随岩屑含量增加,70%岩屑含量的土壤D(θ)明显大于其余3个岩屑含量的土壤,而30%岩屑含量和50%岩屑含量土壤之间的D(θ)无显著差异,且土壤湿润锋前进速率均呈先增加后降低再增加的趋势;岩屑粒径为0.25~2 mm时,土壤湿润锋前进速率和D(θ)随岩屑含量增加逐渐增加。因此,随岩屑含量提高,土壤水分扩散速率整体呈现增加趋势;且泥岩发育的土壤水分扩散速率高于页岩发育的土壤。     

利用RNA-seq筛选调控当归抽薹主要候选基因

当归提前抽薹严重影响产量,而当归抽薹分子遗传机理尚不清楚.本研究利用RNA-seq技术对连续五代抽薹当归的叶片、茎段、种子、根进行测序,对所有组装后的Unigenes进行功能注释,寻找调控当归抽薹主要候选基因.结果表明:在当归的叶片、根、种子、茎段转录本中分别得到7.1、7.63、7.23、6.59Gb数据,通过Nr、...