摘要
把引起豌豆枯萎病的丁香假单胞菌丁香致病变种 Pseudomonas syringae pv.syringae 菌株3319和丁香假单胞菌豌豆致病变种 P.syringae pv.pisi 的模式菌株2452的染色体 DNA 分别用限制性核酸内切酶 HindⅢ完全消化,再用 T_4DNA 连接酶把消化好的 DNA 片段连接到用HindⅢ内切酶消化的质粒载体 pUC19上,然后把重组的质粒载体转化到大肠杆菌(E.coli RR1)中去克隆.把菌株3319和2452的 DNA 用 p^(32)标记做成探针,分别与克隆菌落杂交,筛选出只对菌株3319的 DNA 有特异性的1个重组 DNA 的克隆和对菌株2452的 DNA 有特异性的2个重组 DNA 克隆.再把这3个重组质粒 DNA 分别用 P^(32)标记做成探针,与菌株3319和2452的 DNA 杂交,也显示只对各自 DNA 来源的菌株具有特异性.这3个重组质粒中,有2个携带有菌株2452的 DNA 片段,1个为0.82 kb。另1个略小于0.58 kb,还有1个质粒携带有菌株3319的 DNA 片段,为0.85 kb.
Plasmid vector pUC19 and chromosomal DNAs from strains,pseudomonas syringae pv.syringae 3319 and P.syringae pv.pisi,were seperately completely digested with restriction endonuclease Hind Ⅲ.The fragments were ligated with the digested vector using T_4 DNA ligase.The ligation products were transformed into E.coli RR1.Recombinants were probed with DNAs from P.syringae pv.syringae 3319 and P.syringae pv.pisi 2452.Two recombinants for P.syringae pv.pisi and one recombinant for P.syringae pv.syringae were obtained.The three recombinants were labelled and hybridized to the DNAs from P.syringae pv.syringae 3319 and P.syringae pv.pisi 2452.They were only specific to their homologous chromosonal DNA.The DNA fragments from P.syringae pv.pisi seperately were 0.82 kb and less 0.58 kb.The DNA fragment from P.ksyringae pv.syringae was about 0.85 kb.
