An improvised in vitro vegetative propagation technique for Bambusa tulda： influence of season, sterilization and hormones

Season and concentration of sterilizing agents play a significant role for establishment of aseptic in vitro shoot cultures and sprouting of nodal explants from field growing culms of bamboo species. In the present investigation the nodal segment explants of Bambusa tulda Roxb collected in different seasons and treated with various concentrations of HgC12 showed significant variation in aseptic culture establishment and bud break. The rainy season （July-August） recorded with highest of 78% aseptic culture establishment whereas autumn recorded with lowest 46%. Summer and winter seasons emerged to be the best period, registering 〉 60% in vitro bud break. On the other hand, the autumn season had the lowest value for bud break, i.e. 42%. Among different doses of sterilizing agent tried, HgC12 0.1% found to be suitable for maximum aseptic culture establishment （66%） as well as bud break （59%）. However, among the interactions, summer season and the dose of 0.1% HgC12 exhibited maximum of 73% response for both aseptic culture establishment and bud break. MS medium （liquid） enriched with 5.0 μM BA ＋5.0 μM Kn [Kinetin （N6-Furfuryladenine）] with additional supplementation of 100 μM glutamine ＋ 0.1 μM IAA supported a maximum in vitro shoot multiplication of 4.75 fold. The proliferated shoots were successfully rooted on MS medium （liquid） supplemented 40 μM coumarin. The plantlets transferred to the polythene bags showed 98% survival.

Adventitious rhizogenesis in Bambusa nutans and Bambusa tulda: Influence of seasonal variation, IBA and cutting type

The influence of seasonal variation, indole-3-butyric acid （IBA） and type of cuttings was examined on induction and growth of adventitious roots in Bambusa nutans Wall. and Bambusa tulda Roxb. Singlenode culm and culm-branch cuttings from the mature culms were provided with immersion treatment for 24 h of either water （control） or 2 mM IBA in four different seasons, i.e., spring （mid February）, summer （mid May）, rainy （mid July）, and winter （mid November） and maintained for two months in the mist chamber at the relative humidity of （70±5）% and the tenlperature of （30±2）℃. In B. nutans, adventitious rooting occttrred in both types of cuttings in all the seasons with the best rooting in the summer season i.e., May （88% in culm cuttings） and the least in winter. On the contrary, adventitious rooting was recorded only in culm cuttings in spring and summer season in B. tulda. IBA treatment significantly enhanced rooting, root number and root length; registering 14 to 17 times improvement over control in the best rooting season. Three factor- interactions （season × cutting type × IBA treatment） were significant for rooting in B. nutans and all characteristics, except sprouting in B, tulda. Thus, single-node culm and culm-branch cuttings in B. nutans and culm cuttings in B. tulda treated with 2 mM IBA during spring （February） to summer （May） season are recommended for their clonal multiplication.