In vitro regeneration from protocorms in Dendrobium aqueum Lindley – An imperiled orchid

Abstract

An efficient <i>in vitro</i> plant regeneration protocol from protocorms of <i>Dendrobium aqueum</i> was developed. The uniformly developed protocorms (<i>in vitr</i>o origin) having shoot initials were cultured on half macro strength MS medium (1/2 MS) supplemented with cytokinins (BA, 2iP, KIN and TDZ) at 1, 3, 5, 7, 10 mg l^-1, natural additives (BP and CW) at 1%, 3%, 5%, 7%, 10% and auxins (IBA, NAA, 2,4-D) at 1, 3, 5, 7, 10 mg l^-1 to study their efficacy on complete plant development. A maximum of 9.4 shoots per explant were generated on 3 mg l^-1 of NAA followed by 3% of BP (7.0 shoots). Shoot elongation (1.52 cm) was achieved on 1/2 MS medium fortified with NAA 7 mg l^-1 followed by TDZ 7 mg l^-1 (1.37 cm). Shoots cultured on 1/2 MS medium supplemented with IBA 5 mg l^-1 produced an average of 8.75 roots per shoot, however the lengthiest roots (1.48 cm) were noted in NAA 7 mg l^-1. Healthy rooted plantlets successfully acclimatized in <i>ex vitro</i> condition. The role of complete plantlet production by natural additives could be useful for conservation and cost effective commercial production of orchids.