Establishment and Application of the System for Isolated Microspore Culturein Kale ( Brassica oleracea L. var. acephala DC. ) Cloning and Sequence Analysis of a Mutation-type Cinnamate-4-hydroxyla seGene from Brassica oleracea L. var. acephala DC. Cloning and Sequence Analysis of a Mutation-type Cinnamate-4-hydroxyla seGene from Brassica oleracea L. var. acephala DC. Establishment and Application of the System for Isolated Microspore Culturein Kale ( Brassica oleracea L. var. acephala DC. )