Protoplast Fusion and Brassica Improvement

Brassica coenospecies has been bestowed with a large collection of wild and weedy relatives, which could act as donors of genes controlling agronomically important traits like disease resistance, yield attributes, modified fatty acid composition in the seed etc. Additionally, the cytoplasm of these species could be the sources for developing alloplasmic male sterility systems that are important in developing hybrid mustard varieties. The technology of protoplast culture and protoplast fusion has been very well developed for crop Brassicas and this could be effectively exploited in developing somatic hybrids and cytoplasmic hybrids, in short called as cybrids. This could pave the way for overcoming problems associated with the development of incompatibility barriers and allow for obtaining hybrids of the wild species with the cultivated species and manipulating characters that are controlled by organelle genomes. In Nicotiana species, protoplast fusion resulted in the development of novel mitochondrial genomes and plants carrying novel genomes have differing flower morphology. Protoplast fusion in Cruciferae also nearly invariably results in mitochondrial genome recombination/rearrangement. Hence, protoplast fusion can be effectively utilized in manipulating flower morphology and male sterility in crop Brassicas.