Developing stable progenies of xBrassicoraphanus, an intergeneric allopolyploid between Brassica rapa and Raphanus sativus, through induced mutation using microspore culture

Abstract

Induced mutations were used to improve the low seed fertility of an intergeneric allopolyploid, 'Baemoochae,' xBrassicoraphanus, synthesized following hybridization between Brassica rapa and Raphanus sativus. The mutagen N-methyl-N-nitroso-urethane (NMU) was added to microspore cultures. Four lines of nine in the Mi(2) generation showed very high fertility under controlled pollination. The progeny lines (Mi(3)) confirmed this result under open pollination, and excellent uniformity was observed in plants grown in the field, as well as in their AFLP profile. On attaining high fertility and uniformity, one of the lines was released to farmers as a new leafy vegetable crop. The original nine lines shared very similar AFLP banding patterns, without any large differences between the high and low seed fertility lines. Thus, mutation induction accelerated genetic stabilization of a newly synthesized allopolyploid, xBrassicoraphanus.