Comparative morphogenetic potential of haploid and diploid callus cultures of Brassica juncea L

Shoot morphogenetic potential of microspore and somatic explant-derived calli of Brassica juncea L. on different MS media have been compared. Shoot organogenesis could be induced in anther-derived haploid calli with comparatively high frequencies (18–58%) and on a wider range of combinations of growth regulators. The highest regeneration frequency was obtained on zeatin + NAA medium. The number of shoots per regenerating callus varied considerably, with two of the anther calli regenerating more than 25 shoots in a single culture. In case of cotyledon and hypocotyl-derived callus cultures, only the calli initiated under light responded positively to shoot regeneration at ca 12% frequency and on only one medium each. Cotyledon calli regenerated on zeatin + NAA medium and hypocotyl calli on BAP + IAA medium. Dark-grown white friable calli failed to yield any shoots.