Characterization and Propagation of Interspecific Chimera Plants between Leaf Mustard (Brassica juncea) and Red Cabbage (B. oleracea) Generated by in vitro Grafting

Abstract

Interspecific graft-chimeras between leaf mustard (Brassica juncea) and red cabbage (B. oleracea var. capitata cv. Ruby Ball) were generated by in vitro grafting. Leaf morphological investigation confirmed that the individuals derived from the chimeras by axillary bud culture were periclinal chimeras whose three apical cell layers were the HHR or HRR type. PCR detection confirmed that the periclinal chimeras shared the DNA polymorphisms of their donor plant. Leaf and flower morphological characteristic analyses of the periclinal chimeras suggested that trichome formation and calyx coloring were derived from the first cell layer (LI) of the apical meristem, while the pinnate leaflet, petaloid stamen formation, and peduncle coloring were from the second cell layer (LII) in Brassica. Furthermore, a propagation system for the periclinal chimeras was established by combining axillary bud and soil-less cultures.