Four Streptomyces spp isolates from rhizosphere soils showing somaclonal variation were screened of morphological, antimicrobial, pigment, pectinase activity, isozymes and DNA-fingerprint. Based on visual observation by light and electron microscopes of four St. isolates were identified as St. scab ; St. viridiviolaceus ; St. capillispirales and St. refuineus. They showed different in mycelium and conidia spores as well as variable diffusible pigment in experimental medium. The extend of antibiotics , St. isolates were differed against microbial that exhibited a strong activity against +VG bacteria , yeast ; a weak activity against -VG bacteria and no exhibited fungi . DISC-PAGE of pectinase activity and isozymes appeared differences among four isolates in number and density 5, 5, 4, 5 isozymes of St. isolates respectively. DNA-finger printing was used for molecular analysis of somaclonal variation among four St. isolates. Only three arbitrary primers (among ten tested) were chosen as producing -++polymorphic DNA fragments differentiating four St. isolates. RAPD-PCR revealed polymorphism among four St. isolates, 8 polymorphic fragments (specific bond) with 94% ; 5 monomorphic fragments and revealed unique fragments (genetic marker) 127, 950 and 575 bp of St.scab ,St.capillispirales and St.refuineus respectively. The phylogenetic tree between four isolates appeared that, 4 isolates are close similarity within one group. The results showed that, the somaclonal variation among four ST. isolates depending on genetic variability. |
