Developing Stable Cultivar through Microspore Mutagenesis in ×Brassicoraphanus koranhort, Inter-Generic Allopolyploid between Brassica rapa and Raphanus sativus

摘要

A stable progeny was developed through induced mutation, using microspore culture, of the hybrid (F1F1) produced by crossing a newly synthesized, unstable allopolyploid (F1) and a stable cultivar, BB#1(F1) in xBrassicoraphanus. An F1F1 plant was subjected to the induced mutation system established during production of BB#1. Morphological characteristics of the progeny such as color, and leaf number and length, differed from those of BB#1. The bolting time of the progeny in spring cropping was very late compared to BB#1, allowing it to be grown to an adult plant in spring. Genomic in situ hybridization analysis of pollen mother cells at prophase I identified 19 bivalents, 10 from Brassica rapa and 9 from Raphanus sativus. The glucoraphenin content was almost identical to that of BB#1. Two cultivars are available in the baemoochae crop now. These results indicate that induced mutation using microspore culture is a viable method of stabilizing intergeneric allopolyploids between B. rapa and R. sativus.