SOMATIC EMBRYOGENESIS AND IN-VITRO FLOWERING IN BRASSICA-NIGRA

This report describes a protocol for regeneration of Brassica nigra in vitro from unorganized callus to a highly differentiated stage of flo wering. Callus is initiated from seedling hypocotyl, and root explants and plantlets are obtained via somatic embryogenesis. Shoot cultures can be established from these plantlets. These shoots can either be in duced to flower in vitro or rooted to produce plants which flower ex v itro. Each stage of development is marked with a specific growth regul ator requirement. This has potential as a model system to understand t he cellular and molecular mechanisms involved in morphogenesis, and it can be used to understand the mechanism of change of phase from veget ative to reproductive. An advantage of this system is that in vitro fl owering can be obtained repeatedly in the shoots raised from the axill ary buds of the flowering shoots. The protocol can also be used to pro cure B. nigra gametes under aseptic condition.