Phenotypic instability and epigenetic variability in a population of the wild potato Solanum ruiz-lealii

C.F. MARFIL; E.L. CAMADRO; R.W. MASUELLI

Madison, Wisconsin, USA

Congreso; PAA/ Solanaceae 2006. Genomics Meets Biodiversity; 2006

Potato Association of America, Solanaceae Source, ECP/GR Eggplant Database, Botanical Garden of Nijmegen, Solanaceae Genomics Network

The wild potato species S. ruiz-lealii (2n=2x=24), a putative hybrid between S. kurtzianum and S. chacoense, is endemic to Mendoza province, in Argentina. Recurrent flower malformations, that varied among inflorescences of the same plant, were observed in plants of a natural population. These abnormalities could be result of: genomic instabilities, nucleus-cytoplasmic incompatibility or epigenetic changes. The nuclear, mitochondrial and methylation status of plants with normal and abnormal flower phenotypes were analyzed by AFLPs, restriction analysis and MSAP, respectively. The AFLPs and the restriction patterns of the mitochondrial DNA did not differentiate the stable from the unstable phenotypes. However, the phenogram obtained with the DNA methylation data discriminated the normal and aberrant phenotypes into two different groups, indicating that unstable phenotypes have a similar global methylation status that was different to the status of normal plants. In addition, the intra-population variability regarding DNA methylation was greater that the genomic sequence variability. The importance of considering this source of variability in natural populations and investigating how modifications in DNA methylation could induce flower abnormalities is established.