Characterization of Tomentosa cherry (Prunus tomentosa Thunb.) genotypes using SSR markers and morphological traits     

Qijing Zhang  Guijun Yan  Hongyan Dai  Xinzhong Zhang  Chunmin Li  Zhihong Zhang 《Scientia Horticulturae》2008

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黄瓜cpSSR引物的多态性与通用性     

梁芳芳  李琼  胡建斌  李建吾 《江西农业学报》2010,22(3):1-4

从黄瓜叶绿体基因组序列中设计15对以A或T为重复单元的微卫星引物,其中12对处于基因组非编码区,3对位于基因编码区。这15对引物在21份黄瓜材料中均有扩增产物,但只有非编码区的微卫星表现出位点多态性。每对引物可检测1~3个等位基因,平均2.0个,引物的多样性值(polymorphic information content PIC)从0至0.484,平均值0.202。15对引物在甜瓜和南瓜中均能通用,13对可在西瓜中通用。这些叶绿体引物可用于黄瓜及其近缘种的叶绿体遗传研究。  相似文献   

棉花SSR分子标记在香蕉中通用性的研究   总被引：4，自引：0，他引：4  

郑丽珊  袁有禄  王静毅  冀小蕊  黄秉智  武耀廷 《分子植物育种》2007,5(5):667-672

香蕉栽培品种是由尖叶蕉(Musa acuminata Colla,记为A基因组)和长梗蕉(Musa bilbisiana Colla,记为B基因组)这两个原始野生蕉种内或种间杂交后代进化而成的.目前,香蕉SSR分子标记开发的数量和应用研究非常有限,需要开展其它物种SSR分子标记在香蕉中的通用性研究.棉花(Gossypium spp.)是重要的经济作物,已经从基因组和EST开发了大量SSR分子标记.本研究应用1595对棉花SSR引物首先对A基因组的代表品种贡蕉和B基因组的代表品种野蕉进行转移扩增,得到183对有效扩增的引物.然后以20个香蕉栽培品种和4个野蕉品种对183对有效扩增的引物进行多态性筛选,最后得到111对多态性引物,共扩增到797个等位基因,平均每对引物的等位基因数为7.2.引物多态信息含量(PIC)在0.61～0.91之间.应用非加权类平均聚类方法,在相似系数0.61处将24个品种分为两大类群,类群Ⅰ是以A基因组为主的品种群,类群Ⅱ是以B基因组和A基因组与B基因组杂交的品种群.  相似文献   

IncK plasmid-mediated tetracycline resistance in Edwardsiella ictaluri isolates from diseased freshwater catfish in Vietnam     

Tu Thanh Dung  Freddy Haesebrouck  Patrick Sorgeloos  Nguyen Ahn Tuan  Frank Pasmans  Annemieke Smet  Annemie Decostere   《Aquaculture (Amsterdam, Netherlands)》2009,295(3-4):157-159

Eight tetracycline resistant Edwardsiella ictaluri isolates obtained from diseased freshwater catfish (Pangasianodon hypophthalmus) in Vietnam, and showing different resistance phenotypes to other antimicrobial agents, were studied. The tet genes were determined using PCR. Conjugation experiments were performed to assess transferability of the tetracycline resistance determinant and the size and incompatibility group (Inc) of each tet-carrying plasmid were determined. PCR and sequencing were used for characterization of the co-transferred resistance genes. A tetA gene was demonstrated in the E. ictaluri isolates and for all of them, Escherichia coli transconjugants were obtained. All transconjugants contained high-molecular weight tetA-carrying plasmids (~ 140 kb) belonging to the incK group, as was shown with the PCR-based replicon typing method. The strA–strB, dhfr1 and sul 2 genes were detected on the tetA-carrying plasmids of the transconjugants showing resistance to streptomycin, trimethoprim and sulfonamides, respectively. The dhfr1 gene was found to be located in a class 1 integron as determined by PCR and sequencing. Interestingly, the 3′ CS region of class 1 integrons was not detected by PCR. This study shows the presence of incK plasmid-mediated tetracycline resistance among E. ictaluri isolates from diseased freshwater catfish in Vietnam.  相似文献