Hybridization between European and Asian dandelions (Taraxacum section Ruderalia and section Mongolica)
1. Crossability and breakdown of self-incompatibility
Article first published online: 28 APR 2006
Volume 114, Issue 3, pages 519–529, March 1990
How to Cite
MORITA, T., MENKEN, S. B. J. and STERK, A. A. (1990), Hybridization between European and Asian dandelions (Taraxacum section Ruderalia and section Mongolica). New Phytologist, 114: 519–529. doi: 10.1111/j.1469-8137.1990.tb00420.x
- Issue published online: 28 APR 2006
- Article first published online: 28 APR 2006
- Received 28 November 1988; accepted 11 September 1989)
- Taraxacum (dandelions);
- section Ruderalia;
- section Mongolica;
- breakdown of self-incompatibility;
- diploid-triploid cycle;
- reproductive systems
In order to investigate crossability between the European section Ruderalia Kirschner, H. Øllgaard & Štěpánek and the Asian section Mongolica Dahlst. of the genus Taraxacum Wigg., artificial hybridization experiments were carried out.
After inter-sectional crosses on the diploid level, Mongolica plants showed high fruit-set, not strikingly different from either the control (within-populational crosses) or inter-specific crosses within the same section. However, a substantial decrease of fruit-set was detected when Ruderalia plants were the seed parents.
Electrophoretic analysis revealed that Ruderalia seed parents in inter-sectional crosses showed relatively low out-crossing rates with low fruit-set, whereas Mongolica plants as seed parents showed high out-crossing rates, mostly 100%. These results indicate that the crossing-barrier is stronger in the direction from Mongolica to Ruderalia than vice versa.
Crosses between diploid Mongolica (♀) and triploid Ruderalia (♂) were also successful, although fruit-set was far lower than in 2x-2x crosses, a result which confirms previous reports. Contrary to published accounts, it was found by means of electrophoretic analyses that some 87.5 % of the progeny in 2x-3x crosses were not true hybrids but sexual diploids originating from self-fertilization. Only approximately 12.5 % of the progeny were found to be true agamospermous triploid or tetraploid hybrids. A strong doubt is raised concerning reports in the literature which assume that diploid hybrids originate in 2x-3x crosses. The possible reasons why self-incompatibility was broken down by triploid pollen are discussed.