Genetic variation and inheritance of secondary dormancy in winter oilseed rape(Jörg Schatzki)

In oilseed rape, seed shedding may occur due to pre-harvest pod shatter and due to seed losses during combined harvesting. Only a part of those seeds germinate directly on the soil, others remain viable in the soil for years. Germination of those seeds is prevented by natural induction of secondary dormancy. However, secondary dormant seeds may germinate in subsequent years and they are the main reason for the occurrence of voluntary oilseed rape plants in successive crops. Genetic reduction of secondary dormancy in oilseed rape could provide a mean to reduce the frequency of volunteer plants and especially the dispersal of transgenic oilseed rape. The aim of the present BMBF funded project is to determine the genetic variation and the genotype × environment interactions for secondary dormancy, and to estimate correlations to other seed traits in the winter oilseed rape DH population Express 617 x R53. Furthermore, QTL will be mapped for all recorded traits. Field experiments are performed in two consecutive years (2008/09 and 2009/10) at two locations with two replicates. Seeds harvested from open pollinated plants are used for all analyses, including a laboratory test for secondary dormancy.