外源共生质粒pJB5JI导入紫云英根瘤菌（Rhizobium huakuii）中的稳定性

将碗豆根瘤菌共生质粒ｐＪＢ５ＪＩ导入紫云英根瘤菌７６５３Ｒ及其消除了共生质粒的突变株７６５３Ｒ＋１。两种类型转移接合子在人工合成培养基上繁殖时，ｐＪＢ５ＪＩ能稳定存在，但从它们在碗豆或紫云英上所结根瘤的分离物中，只有部分检测到ｐＪＢ５ＪＩ。以转座子Ｔｎ５及首蓿根瘤菌ｎｏｄ基因为探针，对未检测到ｐＪＢ５ＪＩ质粒的根瘤分离物７６５３ＲＡ９及７６５３Ｒ＋１Ｐａ，进行ＤＮＡ同源性分析，结果表明ｐＪＢ５ＪＩ质粒并没有全部丢失，很可能全部或部分整合到了受体紫云英根瘤菌的染色体中。

THE STABILITY OF EXOGENOUS SYMBIOTIC PLASMID pJB5JI IN RHIZOBIUM HUAKUII

Rhizobium leguminosarum biovar viceae host range plasmid(pJB5JI)was introduced into both the Rhizibium huakuii wild type strain 7653R and its symbiotic plasmid-cured in nodmutant strain 7653R+1.The alien plasmid pJB5JI in both kinds of transconjugants remained stable during frequent transfer on cultural media,but in parts of the isolates from which formed nodules,the pJB5JI was not visualized on gel by Eckhardt procedure,and the DNA of pJB5JI was possibly integrated onto the chromosome of transconjugants.These results indicated that the host plant also exerted an influence on the stability of the exogenous symbiotic plasmids.