Genetic and epigenetic variability in synthetic interspecific hybrids of Solanum and in the natural interspecific hybrid Solanum x rechei

CARA, NICOLÁS; MARFIL, CARLOS F.; MASUELLI, RICARDO W.

Foz do Iguazu

Congreso; International Plant Molecular Biology Congress; 2015

Interspecific hybridization generates genetic and epigenetic modifications such as changes in DNA methylation. Wild potatoes (Solanum, section Petota) are adapted to multiple habitats throughout the Americas, and natural hybridization has proved to be a common feature among species of this group. Solanum x rechei, a natural hybrid that grows sympatrically with its parental species, Solanum microdontum and Solanum kurtzianum, represents an ideal model for studying of the ecological and evolutionary significance of interspecific hybridization. In this study, genetic and epigenetic variability and their correlation with morphological variation was studied in these three species by AFLP and MSAP techniques. Solanum x rechei showed genetic and epigenetic novel patterns not seen in the parental species, in addition to a general demethylation respect to the parental genomes. Morphological variability showed higher correlation with epigenetic than with genetic variability. Bayesian analysis of genetic data revealed the hybrid nature of S. x rechei, by assigning it equally to both parental groups, while the epigenetic information assigned it to a new group. Through controlled crosses the hybrid was recreated and analyzed with the same molecular techniques. Synthetic hybrids presented novel genetic and epigenetic patterns not seen in the parental genotypes, some of which were also found in the natural hybrid. No overall change in methylation levels of the hybrids was found, however many hyper- and hipomethylations were observed. These findings suggest that after the hybridization, new epigenetic patterns are established, and then, selective processes could act on this variability leading to the selection of certain variants.