Prolonged dormancy in the seeds preserved in harvested fruits of Brassica vegetables

The dormancy of seeds which were consecutively preserved in harvested fruits has been studied in three species of Brassica, i.e., B. japonica, B. napus and B. cernua. In B. napus and B. cernua fresh seeds lost their dormancy in 3 months when they were separated from fruits immediately after harvest, whereas seeds showed the prolongation of dormancy for as long as more than 2 years when they were preserved in harvested fruits. In B. japonica mature seeds lost their dormancy in a month after harvest, whether they were preserved in fruits or not. When the seeds which had been preserved in fruits were separated from the fruits, their dormancy disappeared rapidly.