Polyploidization for more compact Petunias

REGALADO GONZÁLEZ, JOSÉ JAVIER; PITTA-ALVAREZ, S.I.

Vienna

Conferencia; Plant Cells in vitro: Theory and Practice; 2016

Vienna International Science Conferences and Events Association

Petunia is one of the most important ornamental plants in the world. Its main drawback is a natural elongation trend. Nowadays this elongation is prevented by the use of growth inhibitors, which are toxic and only effective during the first flowering. Our aim was to develop new varieties of compact Petunias. Our previous results indicated that autopolyploid Petunias are more compact; thus polyploidization could be an alternative to the use of growth inhibitors.For polyploidization, leaves of P. integrifolia and P. axillirias were cultured in MS supplemented with 1 mg/l BA and 0.2mg/l IAI and 0.2 g/l Colchicine during 15 and 30 days. Colchicine killed the majority of cells. However, shoots have regenerated from the survivors cells in 52%/15% of the leaves in 15/30 day treatments respectively (100% in the control). Regenerated shoots were subcultured in MS without hormone for elongation and rooting. Some plantlets regenerated from the medium with colchicine exhibit important differences compared to the original plants, possibly as a result of polyploidization, such as thicker and darker leaves and decreased internode length. The latter could be useful to obtain more compact plants without growth inhibitors. Flow cytometry will be used to confirm that the plants with these special phenotypes are autopolyploids.