Genotypic variation of Agrobacterium-mediated transformation of Italian ryegrass

In the present study, genotypic variation of Agrobacterium-mediated transformation of Korean Italian ryegrass has been evaluated. Mature seed-derived calli of seven cultivars were inoculated and co-cultured with Agrobacterium tumefaciens carrying the binary vector pCAMBIA1301, which contains a reporter gene (gus) and a plant selectable marker gene conferring resistance to hygromycin (hpt) in the T-DNA region. The effects of several factors such as callus type and callus age on transformation effectiveness and the expression of the GUS gene were investigated. The highest transformation effectiveness (6.7 percent) was obtained with the Hwasan 101 cultivar when 9-week-old calli (type-I) were inoculated with Agrobacterium. The overall transformation rates of the examined cultivars ranged from 0.4 percent to 6.7 percent. GUS histochemical assays, PCR, and southern analysis of transgenic plants demonstrated that transgenes were successfully integrated into the genome of Italian ryegrass. Thus, evaluation of transformation effectiveness and selection of a suitable cultivar of Italian ryegrass may improve molecular breeding of this species.

Genetic similarities among Iranian populations of Festuca, Lolium, Bromus and Agropyron using amplified fragments length polymorphism [AFLP] markers

The study of genetic variation and phylogenetic relationships is essential for the efficient selection of superior plant material and conducting introgression breeding programs. In Iran, despite the wide geographical distribution of grasses no report is available on the genetic diversity and relationships of cool season grass populations. In this study amplified fragment length polymorphism [AFLP] was used to study 42 populations from eight species of Festuca arundinacea Schereb., Festuca. pratensis Huds., Festuca. rubra L., Festuca. ovina L., Lolium perenne L., L. rigidum Gaud., Bromus tomentellus Boiss. and Agropyron cristatum [L] Gaertn. The number of amplified products ranged from 11 to 78 per primer combination and a total of 497 markers were scored. Jaccard's genetic similarity coefficients among populations ranged from 0.15 to 0.88 showing high levels of inter and intra-specific genetic diversity. The cluster analysis and principle coordinate analysis [PCOA] reflected the phylogenetic relationships among species and clearly demonstrated differences in the degree of similarity among accessions. Results indicated that AFLP is a useful technique to reveal genetic diversity at different taxonomic levels of grasses and might facilitate the selective introgression of useful genes in plant breeding programs