ISHS Acta Horticulturae 430: VII International Symposium on Flowerbulbs
APPLICATION OF THREE POLLINATION TECHNIQUES AND OF HORMONE TREATMENTS FOR OVERCOMING INTERSPECIFIC CROSSING BARRIERS IN TULIPA |
| Authors: | M.G.M. van Creij, D.M.F.J. Kerckhoffs, J.M. van Tuyl |
| Keywords: | interspecific hybridization, hormone treatments, cut-style method, grafted-ovary method, placental pollination, tulip |
| Abstract:
In tulip, interspecific crossing is restricted by both pre-fertilization and post-fertilization barriers. In order to introduce traits from wild species into the cultivar assortment these barriers must be bypassed. By application of embryo rescue techniques, unique hybrids have been obtained of several interspecific tulip crosses. Recently, four techniques have been tested on their capacity to overcome interspecific crossing barriers in tulip, namely hormone treatments of ovaries, cut-style method, grafted-ovary method and placental pollination. After treating ovaries with 0.1% BAP at 12 days after pollination, seeds were obtained on the plant from the cross T. gesneriana x T. agenensis. This cross has never been given seeds in vivo before. Treating ovaries with 1% BAP seemed to have a negative effect on seedset in compatible crosses, 1% NAA did not give any effect. After the application of the cut-style method, the percentage pollen tube penetration did not increase in crosses between T. gesneriana and 5 other Tulipa species. Apparently, crossing barriers were not overcome by using the cut-style method, nor after using the grafted-ovary method. After placental pollination, pollen tube penetration percentages were not increased compared to stigmatic pollination, however, most of the penetrated ovules with pollen tube penetration showedd embryo germination. | |
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