Phenotypic and epigenetic variability induced by allopolyploidization in potato

DUARTE, P; MARFIL, C.F; BORGO, R; MASUELLI, R. W.

Congreso; 11th international Congress of Planta Molecular Biology; 2015

Polyploidy is one of the mayor forces in the evolution of the angiosperm. More than 70% of the modern plants are polyploids and many of them are allopolyploids as a result of the genome merge of two or more different ancestors. The union of divergent genomes in the hybrid nucleus may induce genetics and epigenetics rearrangements, including exchanges between genomes and alteration of gene expression. Until now the phenomenon of allopolyploidization was not studied in potato species. The aim of this work is to evaluate the effects of genome duplication in interspecific hybrids of potato. Diploid interspecific hybrids between Solanum tuberosum and Solanum kurtzianum were compared, as a control, with synthetic allotetraploid lines originated by in-vitro colchicine duplication and colchicine treated diploid lines that not duplicate their genomes (colchicine controls). Microsatellite and AFLP analysis showed no polymorphism between allotetraploids and diploids lines. However, methylation changes were detected between allotetraploids and both diploids control lines. The results showed that the allopolyploids have higher leaf area, lamina thickness, mean diameter of vessel lumen and total chlorophyll content. These results support the hypothesis that polyploidy may activate genes involved in photosynthesis and in the increase in leaf areas suggesting an important role in increased photosynthesis in the allopolyploids.