EFFECT OF INTERSPECIFIC GRAFTING ON GENOMIC DNA METHYLATION

Grafting in woody species such as conifers has allowed the reversion of phenotypic characteristics from the adult stage to more juvenile stages, i.e., reinvigoration. The molecular mechanisms that allow reinvigoration of adult plant material and that depend on the rootstock are not clear. However, it has been shown that grafting involves epigenetic modifications in scions and genomic DNA methylation is one of them. In this work, we studied the effect of interspecies grafting in Pinus radiata D. Don and variables of scion behavior as an effect of changes in the methylation patterns of genomic DNA extracted from cauline apices. To address the proposed objective, terminal branches of an 8-year-old adult P. radiata were grafted onto five rootstocks of the genus Pinus. Among the variables of scion behavior, morphometric characteristics of the graft, scion survival and the stage of acicular development were evaluated. The methylation patterns of genomic DNA in cauline apices of grafted scions were determined using methylation-sensitive ISSR molecular markers (MS-ISSR).