Micropropagation of three genotypes of Indian mustard [{Brassica juncea} (L.) Czern.] using seedling-derived transverse thin cell layer (tTCL) explants

Micropropagation of three genotypes of Indian mustard [\textit{Brassica juncea} (L.) Czern.] using 7-days old seedling-derived transverse thin cell layer (tTCL) explants was accomplished. The genotype, explant source and addition of silver nitrate to the medium significantly influenced shoot bud induction. MS medium with 26.6 \(\mu\)M of 6-Benzylaminopurin (BAP) and 3.22 \(\mu\)M of 1-naphtaleneacetic acid (NAA) was identical (in the case of cotyledon tTCLs whatever the organ) and superior for the induction of buds (in the cases of petiole tTCL explants of genotypes 1 and 2 and hypocotyl tTCL explants of genotypes 1 and 3) than 53.3 \(\mu\)M of BAP and 3.22 \(\mu\)M of NAA. However, 53.3 \(\mu\)M of BAP was superior for the induction of buds than 26.6 \(\mu\)M in the presence of the same concentration of NAA for petiole tTCL explants of genotype 3 and hypocotyl tTCL explants of genotype 2. The addition of silver nitrate significantly enhanced the rate of shoot induction in all genotypes. Cotyledon-derived tTCL explants exhibited the highest shoot bud induction potential and was followed by petiole- and hypocotyl-derived ones. Addition of 10 \(\mu\)M of silver nitrate to BAP and NAA supplemented medium induced higher frequency shoot bud induction (up to 100 %) with the highest means of 4.45 shoots per cotyledon-derived tTCL explants obtained with the genotype 2. Shoot regenerated were rooted on MS basal medium without PGRs which induced 99 % of roots per shoot. The plantlets established in greenhouse conditions with 99 % survival, flowered normally and set seeds.