CONICET | Buscador de Institutos y Recursos Humanos

Molecular markers could allow determining that no genetic changes through somaclonal variation had occurred along the whole process of genetic transformation. In that sense, the aim of this work was to identify and quickly predict similarity to parental line of different transgenic events by using Target Region Amplified Polymorphism (TRAP) markers. DNA of transgenic events, wild type genotypes and other sugarcane varieties was characterized by seven to nine combinations of TRAP primers. Amplification products were separated by electrophoresis on polyacrylamide denaturing gels in a 4300 DNA Analyzer (Li-cor), images were analyzed and bands were transformed into either a 0 or 1 matrix. Similarity was calculated by using Jaccard coefficient and dendrograms were generated using UPGMA analysis. At first instance, TRAP were used to establish whether the close growth resemblance between herbicide tolerant lines and their parental variety, RA 87-3, was also true at the genetic level. The genetic characterization confirmed the preliminary phenotypic evaluations since transformed lines exhibited none or only minor genetic changes whereas lines with growth aberrations also included in the analysis, showed a significant degree of polymorphism. The incorporation of other genotypes as controls allowed us to internally evaluate the accuracy of the survey assuring that a significant number of polymorphic bands were analyzed. Considering results obtained, these markers were routinely applied to characterize transgenic events of LCP 85-384, TUCCP 77-42, TUC 95-10 and TUC 03-12 at early stages of the process. In summary, our results showed that the use of TRAP markers to genetically characterize promising transgenic lines is a rapid and recommendable first approach to identify transformed plants genetically close to their parental genotype as they could be applied at the first stages of evaluation to select the most valuable lines to carry out field tests.