In vitro plantlet formation in Carrizo citrange: A promising citrus rootstock

Abstract

The shoot tip and nodal segment explants from three-year-old plants of Carrizo citrange were exposed to mercuric chloride (0.1%) for different durations. In case of nodal segments, maximum survival (39.00%) and minimum microbial contamination (60.80%) was observed with mercuric chloride treatment for 10 min., whereas, shoot tips failed to establish. The explants were established on Murashige and Skoog (1962) medium supplemented with different concentrations of BAP, NAA and IBA. Maximum culture establishment (97.20%) was observed highest on MS medium supplemented with BAP (2 μM) + NAA (1 μM). Season of culturing also effected the establishment of shoot cultures as maximum establishment (96.60%) was observed during April- May followed by August-September. The highest shoot proliferation (3.64 per explant) and shoot length (3.71 cm) were also recorded on MS medium supplemented with BAP (2 μM) + NAA (1 μM). The micro-shoots were rooted on half-and full-strength media supplemented with different concentrations of IBA and NAA. Earliest root induction (10.60 days) and maximum rooting (53.89%) were observed on MS medium supplemented with IBA (10 μM) + malt extract (500 mg/l). Maximum number of roots per shoot (1.37) and root length (5.0 cm) were observed on half-strength MS medium containing IBA (2.5 μM) + NAA (2.5 μM). The maximum ex vitro plantlet survival (81.4%) was observed in potting mixture consisting of cocopeat + vermiculite + perlite (2:1:1).