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

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

BMC PLANT BIOLOGY

BIOMED CENTRAL LTD

Año: 2009 p. 1 - 16

1471-2229

The wild potato Solanum ruiz-lealii (2n=2x=24), a species of hybrid origin, is endemic to Mendoza province, Argentina. Recurrent flower malformations, which varied among inflorescences of the same plant, were observed in a natural population. These abnormalities could be the result of: genomic instabilities, nucleus-cytoplasmic incompatibility or epigenetic changes. The nuclear and mitochondrial DNA of plants with normal and plants with normal and abnormal flower phenotypes were analyzed by AFLPs and RFLP analysis, respectively. Also, the wide genome methylation status and the level of methylation of a repetitive sequence were studied by MSAP analysis and southern blots, respectively. The AFLPs markers and the restriction patterns of the mitochondrial DNA did not differentiate the normal from the abnormal phenotypes. However, methylation patterns of nuclear DNA discriminated the normal and abnormal phenotypes into two different groups, indicating that abnormal phenotypes have a similar methylation status which was different to the methylation patterns of normal plants. The abnormal flower phenotype was obtained treating a normal plant with 5-Azacyitidine, a demethylating agent, giving support for the participation of the DNA methylation in the origin of flower abnormalities. In addition, the variability regarding DNA methylation was greater than that for nucleotide sequence. The importance of considering this source of variability in natural populations and how modifications in DNA methylation could induce flower abnormalities is discussed.