In vitro growth and shoot multiplication in Terminalia bellerica roxB. under controlled carbon dioxide environment.

The shoot cultures of Terminalia bellerica Roxb. were grown on Murashige and Skoog's medium containing 1.5 mg 1(-1) BAP (6- benzyl aminopurine), and supplemented with or without sucrose (3%). A range of CO2 concentrations (0.0, 0.6, 10, 40 g(-3)) was provided in small acrylic chambers by using different concentrations and combinations of NaHCO3 (sodium bicarbonate), Na2CO3 (sodium carbonate), KHCO3 (potassium bicarbonate) and K2CO3 (potassium carbonate). To obtain a CO2-free environment, a saturated solution of 10% of KOH (potassium hydroxide) was kept in the chamber. Complete absence of carbon source caused death of shoots within 20 days. Under controlled and enriched CO2, the shoots grew fully photoautotropically on sucrose-free medium. The growth of cultures was better with carbon dioxide (40 g(-3)) than sucrose (3%) in the medium. Maximum number of shoots, number of leaves per cluster, fresh and dry weight and chlorophyll contents were recorded when both sucrose and CO2 (40 g(-3)) were provided to the culture.

Micropropagation of Terminalia arjuna Roxb. from cotyledonary nodes.

Cotyledonary node explants excised from 21 day old seedlings of T. arjuna produced multiple shoots when cultured on full strength MS or modified MS (1/2 strength major salts and Fe-EDTA) medium supplemented with different concentrations (0.1-1.0 mg/l) of BAP. Maximum 8.9 shoots/explant could be recorded after 30 days of inoculation on modified MS medium supplemented with BAP (0.5 mg/l). A proliferating shoot culture was established by reculturing the original cotyledonary nodes (2-3 times) on shoot multiplication medium after each harvest of the newly formed shoots. Shoots (each having 2-3 nodes/shoot) thus obtained were also used as a source of nodal explant that gave rise to 1-2 shoots when cultured on modified MS+BAP (0.5 mg/l) medium. Thus, 45-55 shoots could be obtained after 60 days of culture initiation from a single cotyledonary node. About 88% shoots rooted well after 15 hr pulse treatment with IBA (1 mg/l) in liquid MS medium followed by transfer to modified MS medium without IBA. About 80% of these plantlets were successfully acclimatized in plastic pots containing sand and soil mixture and 70% plantlets transferred in the field those survived even after 6 months of transplantation.