Tissue culture of mangosteen (Garcinia mangostana L.), pawa (G. speciosa Wall.) and somkhag (G. atroviridis Griff.)

Three species of Garcinia, mangosteen (G. mangostana L.), pawa (G. speciosa Wall.) and somkhag (G. atroviridis Griff.) were cultured in various culture media containing various plant growth regulators. The results showed that a high number of shoots (20-50) was induced in mangosteen and pawa. Polyembryony could not be induced in cultured seeds of somkhag. The best results on callus induction from mangosteen leaves was obtained in basal Murashige and Skoog (MS) medium supplemented with 3 percent sucrose, 500 mg/l polyvinylpyrroridone (PVP), benzyladenine (BA) and thidiazuron (TDZ) at the same concentration of 0.5 mg/l. The medium was solidifed with 0.15 percent Gelrite. In case of pawa leaves, the medium containing 0.25 mg/l naphthaleneacetic acid (NAA) and 2.5 mg/l BA provided the greatest callus, whereas somkhag leaves provided the best result on callus induction in the medium containing 0.5 mg/l NAA and 1.0 mg/l BA. Callus obtained from cultured leaves of both mangosteen and pawa were classified as compact nodular or meristem nodular callus while that of somkhang were friable ones. The callus formation from leaf explants originated from proximal region and wounds at mid rib. The same response was obtained in all species. Clonal propagation of mangosteen and pawa was performed by the induction of shoots directly from culturing seeds on modified MS (MMS) (20 and 50 shoots) and young leaves raised in vitro on woody plant medium (WPM) containing 5 mg/l BA (2-5 shoots). In another way, it might be propagated via meristematic nodular callus which provided 10-20 shoots/callus/month. For propagated of somkhage, nodal or node with shoot tip explants were cultured on WPM containing 3 percent sucrose, 500 mg/l PVP, 0.1 mg/l thiourea (TU) and 0.1 mg/l BA. After culture for 2 weeks, half-strength liquid MS medium containing 0.06 mg/l NAA and 0.03 mg/l BA was added and cultured for further 4-6 weeks. By this method of culture, 20-30 shoots per explant were produced.