In vitro propagation protocol for Ex-situ conservation of Pyrenaria khasiana var. Lakhimpurensis - An endemic plant to eastern Himalaya

An agile and reproducible protocol for in vitro propagation of Pyrenaria khasiana var. lakhimpurensis, an endemic plant to eastern Himalaya was carried out successfully. The mature seeds of this tree were collected from semi-evergreen forest of Dullung Reserve Forest, North Lakhimpur district of Assam. In vitro seed germination, multiple shoot induction and in vitro rooting experiments were carried out in woody plant medium. Benzyladenine alone and benzyladenine in combination with gibberellic acid was tried for multiple shoot induction. Benzyladenine (8 mg/L) gave highest number of shoots (2.4) per explant with a maximum shoot length of 1.45 cm observed at BA (1 mg/L). The combination of benzyladenine (1 mg/L) and gibberellic acid (4 mg/L) gave highest number of shoots (5.2) per explant with a maximum shoot length of 4.43 cm. 1 node, 2 nodes and 4 nodes were used for multiple shoot induction studies and it was observed that 4 nodes gave optimum number of shoots (40.82) and shoot length (5.039 cm) after 4 weeks of experiment. Among the auxins investigated for root induction, indole butyric acid IBA at 2 mg/L gave the highest number of roots (10.3 per shoot) with root length of 2.35 cm. Survival rate of in vitro raised seedlings was found to be 70% when transferred from laboratory to land. This is the first scientific report on tissue culture of the genus Pyrenaria of Theaceae family.