PRELIMINARY RESULTS TO ESTABLISH A SPEED-BREED PROGRAM BASED ON HEAT-INDUCED PRECOCIOUS FLOWERING OF APPLE PLANTS CONTAINING THE FLOWERING LOCUS T GENE FROM POPLAR (POPULUS TRICHOCARPA)
Apple breeding remains a slow process due to protracted generation cycles. Shortening the juvenile phase to achieve the introgression of traits from wild species into pre-breeding material in a reasonable time frame is a great challenge. Within the last ten years it has been shown that the juvenile phase of fruit trees can be effectively shortened by using gene transfer technologies. In 2007 we succeeded in breaking the juvenile phase in apple by over-expressing the BpMADS4 gene, a Fruitful-like gene of silver birch (Betula pendula Roth.) in the apple cultivar Pinova and subsequently a crossbred-breeding program based on early flowering plants and marker-assisted selection was initiated (Flachowsky et al., 2007, 2011). Expression of the putative florigen-like gene FLOWERING LOCUS T (FT) has been shown to accelerate the onset of flowering in a number of plant species, including the tree species poplar. We introduced the FT genes from poplar (PtFT1, PtFT2) into the apple cultivar Pinova, all driven by the heat-inducible promoter Gmhsp 17.5-E (HSP) from soybean. We investigated the expression of the transferred genes using different induction conditions.
Wenzel, S., Flachowsky, H. and Hanke, M.-V. (2013). PRELIMINARY RESULTS TO ESTABLISH A SPEED-BREED PROGRAM BASED ON HEAT-INDUCED PRECOCIOUS FLOWERING OF APPLE PLANTS CONTAINING THE FLOWERING LOCUS T GENE FROM POPLAR (POPULUS TRICHOCARPA). Acta Hortic. 976, 471-476
transgenic lines, juvenile phase, Malus, PtFT1, PtFT2