STUDIES ON THE PROPAGATION OF RED SANDAL WOOD (Pterocarpus santalinus Linn.~, AN ENDANGERED MEDICINAL TREE SPECIES
Red sandalwood is a tree species originated in India, which is highly prized for anarray of medicinal and industrial uses, and thus being over exploited from theirnatural habitates. Since there is no systematic cultivation, at the face of increasedexploitation red sandalwood has become an endangered species. The populationsize in Sri Lanka has limited only to just a few trees which were introduced fromIndia. The number of seed bearing trees are limited further compelling to initiatea tree multiplication program.
At the wake of this situation, the current work was started to develop a rapidmultiplication program for red sandalwood employing sexual and asexuel meansof propagation. After a through survey a cluster of four red sandal wood treesincluding two bearing trees were found to obtain seeds and vegetative material.Seeds fallen under the tree, which were collected daily and hand picked fullymature seeds were used for germination studies, Seeds were found extremelyrecalcitrant and lose viability within a week. Prior to germination, wings of theseeds were clipped and pre treated as follows; over night soaking mechanicalremoval of hard seed coat, gibberalic acid treatment. Eventhough, the tetrasoliumtest proved that seeds are viable (before germination), there were no signs ofgermination over a period of one month. Subsequently it was found that, seedsare not viable anymore, Seeds seem quiescent, not ready for germination andloose viability soon due to its recalcitrant nature.
Vegetative propagation is attempted via, air layering, stem cuttings and throughtissue culture. Induction of root formation was tried with the application ofauxins: NAA and IBA under mist propagation in sand medium. Double modalcuttings with a triplet of leaves were used in semi-hard wood type material, whilethe same without leaves was used in hard-wood. Callus formation and theformation of root primodia has started from 6-8 weeks after planting in semi-hardwood with leaves. In the hard wood, cut surface was completely covered withreddish-purple colour stain. There was no sing of the formation of ca11\us or rootprimodia. Callus formation was obtained from leaf disks with auxins andcytokinins in woody plant (WP) medium