Micropropagation studies in almond (Prunus dulcis Mill.) cv. ‘Shalimar’

Surface-sterilized forced shoots tips were inoculated on different basal media supplemented with various combinations of growth regulators. Quality and quantity of growth regulators and nutrient media were found crucial for culture establishment. Optimum culture establishment was achieved on ½MS medium containing benzylamino purine (BAP) + indole butyric acid (IBA) [0.50 + 0.1 mg L⁻¹] where 63.33% morphogenetic response was observed. Callusing at the base of initiating cultures was minimum with BAP + IBA (0.25 + 0.01 mg L⁻¹). Micro-shoots from the established cultures were sub-cultured on MS media supplemented with BAP and NAA (naphthalene acetic acid) alone or in combination for axillary shoot proliferation. Maximum proliferated cultures (80%) with high number of shoots explant⁻¹ (13.7) and proliferation grade (3.9) was obtained with BAP (0.40 mg L⁻¹) + NAA (0.01 mg L⁻¹). BAP proved superior to NAA during axillary shoot proliferation. Micro-shoots (10–15 mm) from proliferated cultures were subcultured in root induction medium (MS medium supplemented with IBA) and incubated under darkness for 10 days at 24±1°C and then transferred to root development medium (hormone-free MS medium) and incubated under normal culture room conditions. The rooting of micro-shoots, root length and number of roots shoot⁻¹ were highest in treatment IBA (1.0 mg L⁻¹).