Abstract
Amphidiploid plants between Brassica campestris (AA) and B. oleracea (CC) were produced by ovule culture, and the pollen and selfed seed fertility of the amphidiploid plants obtained was investigated. For ovule culture, the optimum time was 15-20days after pollination, and the optimum medium was B5 medium supplemented with coconut milk 150ml/l, kinetin 2.5mg/l and NAA 2.5mg/l. In cruciferous leaf vegetables, plants were obtained from 29 cultured ovules in 12 crosses from 28 cross combinations, while, in cruciferous leaf-stem vegetables, plants were obtained from 119 cultured ovules in 15 crosses of 24 cross combinations. In the F1 generation of amphidiploids, the frequency of plants with a high pollen fertility was high while that of plants with a high seed fertility was low. In the F2 generation selected from F1 plants, the frequency of plants with a high pollen fertility as well as with a high seed fertility was higher than that in the F1 generation. Moreover, plants with more than 10 seeds in one pod were obtained, indicating that the fertility in the F2 generation was improved by selection. Although the correlation between pollen fertility and seed fertility was not significant, it was difficult to obtain seeds from the plants with a pollen fertility below 70% in leaf vegetables, and below 60% in leaf-stem vegetables. It is suggested that plants with a pollen fertility above 80% are required for obtaining plants with a high seed fertility in both leaf and leaf-stem vegetables.
