Rapid in Vitro regeneration of Teakwood, An important timber and wood plant

Abstract

Tectona grandis L. commonly known as teak is a commercially important, tropical hardwood tree species that has several applications in the lumber industry. In this experimental work of in vitro clonal propagation, the protocol has been established for regeneration of teakwood (Tectona grandis L.) plants with MS media beside with the supplementation of various plant growth hormones. Nodal and leaf explants of teakwood were used for callus induction and plantlet regeneration. Maximum percentage of callus formation was observed in MS medium supplemented with 2,4-D at a concentration of 2.0 mg l-1. Multiple shoots were observed from nodal segments through axillary bud proliferation. Maximum shoot multiplication percentage was achieved on MS medium supplemented with 6-benzyladenine (BAP) (2.5 mg l-1) and α-naphthalene acetic acid (NAA) (1.0 mg l-1). Cultures have been continuously subcultured to new media supplemented with same hormone treatment after every 3-4 weeks. Multiple shoots of high quality were produced in vitro from node explants. An average of about 7 shoots/ uninodal explants was obtained in 3.5 weeks of culture on MS medium. When shoots were rooted by supplementation with NAA (2.5 mg l-1) in combination with kinetin (0.2 mg l-1) the frequency of rooting of shoots was better than any other combinations. More than 95% of shoots were developed strong and highly ramified roots on MS medium containing NAA (2.5 mg l-1) with Kinetin (0.2 mg l-1). In vitro raised plantlets were regenerated on MS medium supplemented with 0.5 mg l-1 of NAA and acclimatized on vermiculate before transferring them to field for hardening. Shoots were successfully rooted and acclimatized to greenhouse conditions. In-vitro plantlets were planted in pots containing autoclaved mixture of soil: sand: farm yard manure (1:1:1) and grown in the green house for hardening.