The occurrence of genomic changes in transgenic rice plants produced by infecting calli with Agrobacterium tumefaciens has been verified by molecular tools. The AFLP and RAPD analysis of ten non-transgenic and ten transgenic plants showed genomic homogeneity among controls and verified genomic changes within the transgenic population. The comparison of data produced in this and in previous analyses of transgenic rice populations obtained with different transformation approaches showed that transgenic rice produced by A. tumefaciens treatment is characterised by fewer genomic changes than plants produced via protoplast treatment, but far more than those produced with particle bombardment or cell electroporation. From a practical point of view, none of the rice transformation protocols avoid genomic changes. The use of the ones that result in the lowest level of genomic modification may considerably reduce somaclonal variation in the selected transgenic plants.

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1) Dipartimento di Biologia, Università di Milano, Via Celoria no 26, 20123 Milan, Italy E-mail: francesco.sala@unimi.it Phone: +39-2-26604322

(2) DBSF, Università dell' Insubria, via Dunant 3, 21100 Varese, Italy