In-vitro Regeneration of Apple Cultivar (Malus domestica L. cv. Galmast)

Double sterilized and pre-chilled shoot apices of Galmast cultivar obtained from mature trees (MTSTs) and in vitro raised seedlings (SBSTs) were inoculated on MS medium augmented with BA, Kn and TDZ with and without PG. Increase inBA concentrationup to 5.0µM resulted in axillary shoot proliferation in about 40% shoots with a maximum of 14±0.72 shoots per explant. SBSTs (seedling born shoot tips) of same cultivar developed light yellow loose callus (LYLC) when they were cultured on MS(×½) medium fortified with BA(2.0-3.5µM) and produced axillary and adventitious shoots when the same medium was supplemented with BA(4.0-5.0µM. The best response was observed on MS(1/2) + BA(4µM) + PG(10µM) However, about 40% SBSTs showed axillary shoot proliferation on MS(1/2) + TDZ(4µM) + PG(10µM) and produced a maximum average number of 40±0.72 shoots per subculture. However, 25-30% shoots showed axillary shoot proliferation (ASP) with further increase in the concentration of TDZ to 4.0, 4.5 and 5.0µM with PG(10µM). The number of shoots produced was 14±2.11, 12±0.32 and 14.±0.45. The shoots obtained through the mature tree explant culture (MTEC) and seedling born explant culture (SBEC) were sub cultured onto rooting medium containing auxins like IBA, IAA, NAA. Increase in its concentration to 2.0 and 2.5µM resulted in development of adventitious roots in about 60% plants obtained through MTEC with an average of 14±0.82 roots per shoot. When the medium was fortified with IBA(2.0µM) + PG(10µM). When the concentration of IBA was increased further to 2.5µM the micro shoots produced adventitious roots (with cent per cent response) having an average number of 8±0.65 roots per micro shoot. Further increase in the concentration of IBA to 3.0, 3.5, 4.0, 4.5and 5.0µM favoured formation of callose roots but with decreased response. Best root initiation and elongation to obtain complete plantlets from the shoots derived from explants was observed on MS (1/2) supplemented with IBA(2.5µM) + PG(10µM).