Crown gall caused by Agrobacterium spp. has been observed in various crop species and in several provinces of Iran in recent years. In an attempt to identify the Agrobacterium species causing the disease in different areas of the country, strains were isolated from various infected crop species and characterized by phenotypic features, electrophoretic profile of cell proteins and BOX IR fingerprinting.On the basis of their phenotypic features, the strains were differentiated into three separate groups. The phenotypic characteristics of the first group of strains were closely similar to those of A. tumefaciens (Rhizobium tumefaciens). Members of the second group, isolated from infected grapevines were also identified as A. tumefaciens. Strains of the third group were phenotypically different from all described species, but appeared to be more similar to A. tumefaciens. These strains were not able to grow on any of the selective media tested and displayed a limited host range, infecting mainly sweet cherry All strains had a similar plasmid profile. The electrophoretic profile of cell proteins of the strains was different, although some similarity of the pattern was noted in the high-molecular weight region. In fingerprinting using BOX IR primer, a high level of heterogeneity was observed, nonetheless two major groups were differentiated. Phenotypic features appeared to be reliable criteria in identification of Agrobacterium species encountered in this study.

During the years 1997-1998, thirty-one Agrobacterium isolates were obtained from gall and sap of infected grapes as well as from soil in vineyards of Fars and Kohkilouyeh and Boyerahmad province. Two pathogenic and one non- pathogenic isolates of Agrobacterium tumefaciens Biovar1 were selected and their cell protein patterns compared through gel electrophoresis. A pathogenic and one non- pathogenic isolate of A. vitis and A. tumefaciens Biovar1 were selected from which antisera were prepared. Serological studies based on agar gel diffusion placed bacterial isolates in 4 serogroups while slid agglutination test placed the isolates in 6 sergroups. A comparison of cell proteins pattern showed that A. vitis and A. tumefaciens Biovar1 isolates were heterogenous, even though similar protein bands existed among the isolates.

Atropa belladonnais one of the most important medicinal plants in Solanaceae family.It contains tropani alkaloids that often are synthesised in root. Present study was conducted in order to induction of hairy root in A.belladonna using gene transfer via Agrobacterium rhizogenesmethod. The stem explants with Agrobacterium suspensions harbouring rolB gene were inoculated. Then, in order to direct regeneration, five compounds (MS, MS+3 mg/l Kin , B5, MS+12 mg/l Kin, B5+5 mg/l Kin)) in a completely randomized design with three replications was used. The statistical analysis indicated that among treated hormone, 12 mg /l KIN level in MS medium showed the most shoots direct regeneration. Two methods for the analysis of transgenic plants, phenotypic (observed in hair roots of transgenic seedlings), gene amplification of the rolB (using PCR) was used.

Agrobacterium tumefaciens mediated transformation may offer a better alternative than the biolistic gun for genetic transformation of maize plants. This gene delivery system results in a greater proportion of stable, low-copy number transgenic events than does the biolistic gun, and is highly efficient. In the present work, we studied maize transformation using A. tumefaciens by identifying some important factors that affect transformation efficiency subsequent tissue culture and regeneration of transgenic plants. Although, all genotypes produced embryogenic calli, S61 and A188 lines had higher percent (75% and 71% respectively) of regeneration than the other ones. Transformant events obtained when immature embryos (1.5-2 mm) were inoculated with A. tumefaciens LBA4404 harboring a standard binary vector pCAMBIA3301 after 72 h pretreatment culture of the embryos. Polymerase chain reaction (PCR) confirmed the presence of the gus and bar genes in the genome of regenerated plants. The transformation frequency (the number of independent, PCR-positive transgenic plants per 100 embryos infected) was 6.45% for S61 genotype. Therefore, our results identified suitable genotype (S61), embryo size (1.5-2 mm), A. tumefaciens strain (LBA4404), pretreatment culture, and appropriate antibiotic (Timentin) for Agrobacterium mediated transformation of Z. mays.

Stunting and declining symptoms on 3-5 year old apple trees grafted on Maling rootstocks were associated with uneven growth of root and presence of numerous thin and tender roots, similar to hairy root symptoms, on the main and lateral roots of the trees. The growth of the main root appeared to be arrested. Symptoms were observed on trees grown in two orchards in Semirom in Isfahan province and on apples grafted on Maling-Morton (MM) rootstocks in a nursery in Mashhad, Khorasan province. Segments of roots with hairyroot symptoms were thoroughly washed under tap water, rinsed in sterile distilled water (sDw), and then minced with a sterile razor blade in a few drops of SDW in a Petri plate. The suspension, following a 20-30 min standing at room temperature, was streaked onto plates of 2E and potato dextrose agar + calcium carbonate media and incubated at 25-27°C. White mucoid colonies appearing on both media after 4-5 days of incubation were isolated and used in phenotypic and genotypic characterization and identification. All isolates induced formation of copious amounts of callus on carrot root slices, but none produced any noticeable number of roots on the slices, up to one month post-inoculation. Twenty five of the 60 strains isolated were used as representatives in further characterization tests. The strains were motile, oxidase positive, and catalase positive, could grow on media containing 2% sodium chloride and at 33°C. They formed pellicle on ferric ammonium citrate and used sucrose and citrate as the sole carbon sources for growth. None produced 3-ketolactose nor utilized melezitose or malonate. In polymerase chain reaction (PCR) assays, with ipt and vir D primers, the species-specific fragments of 427 bp and 224 bp long were amplified, respectively, using from DNAs of all strains as templates. Based on the results of phenotypic tests and PCR assays, the strains belong to Agrobacterium tumefaciens (Rhizobium radiobacter). Similar root-inducing strain of A. tumefaciens have also been isolated from cucumber roots in England and named rhizogenic A. tumefaciens .