الفهرس 
Plasmids and symbiosis in rhizobiumOnly 14 pages are availabe for public view
 |  | from | 142 |  |  |
| | | from | 142 | | |
Abstract
The present investigation was carried out to study the molecular genetics of some Rhizobium strains in Egypt. It aimed also to describe a transformation system depends on transfer of plasmid DNA from some fast grower Rhizobium strains (R. trifolii B200, R. leguminosarum MI, R. phaseoli 401, R. meliloti M5 and R. spp. Ar.2) to some slow grower Rhizobium strains (B. japonicum 110 and 1577 strains and R. spp. Cow. 7). Moreover, there were other two purposes for this study, the first was to test whether the nod and nif genes can be expressed in different Rhizobium strains. The second was to test the production of some ~hizobium strains with wide host-range. The obtained results could be summerized as follows: 1- Test of sensitivity or resistance to some antibiotics Ampicillin (Amp.), Penicillin (Pen.), Streptomysin(Stp.), ~etracyclin (Tet . ) , chloramphenicol (CAMP) , Vilosif (V. ) , Kanamycin (K.) and Erthromycin (E.) were applied for all used ~hizobium strains. Results showed that: 1.a-R. leguminosarum F33, R. trifolii B200, R. trifolii MI and R. phaseoli 401 strains were resistant to Pen. only and sensitive to the other applied antibiotics. 1.b-R. leguminosarum M1 strain was resistant to both Amp. and Pen. while was sensitive to the other antibiotics.