In Vitro Culture for Micropropagation, Somatic Embryogenesis, Somatic Mutation, and Somatic Hybridization in Brassica juncea

Development of Brassica juncea in vitro regeneration protocol can be a useful tool for breeders to select genotypes having interesting traits which can be related to the oil production which is the main goal for an oilseed crop. Several techniques have been mentioned for their possible application in breeding programs, starting from the explant and finishing with regenerated plant acclimatation. Explant regeneration process needs the optimization of protocol for the medium composition, its environmental conditions and plant selection. Regeneration of explant is carried out via organogenesis through the excised organs in vitro regeneration or via somatic embryogenesis (SE) which consist in the production of somatic embryos following the typical stages of the embryo’s development (from “globular” to “heart” stage). Organogenesis is also studied to improve the efficiency of Rhizobium radiobacter gene mediated transformation protocol for the infected explant regeneration. Breeding programs are also focused on the production of homozygous pure lines through androgenesis generating doubled haploid (DH) lines, homozygous at each locus. In contrast, it is possible to enhance the heterozygosity and genetic variability through the somaclonal variation of mutant hybrids which have different traits compared to the parental plant. Protoplast fusion is a technique which allows the production of hybrid and cybrid combinations of species that are sexually incompatible facilitating the intergeneric and the intraspecific hybridization without genetic transformation. In this chapter these techniques have been evaluated and described comparing several methods and results.