Germplasm conservation of patchouli (Pogostemon cablin Benth.) by encapsulation of in vitro derived nodal segments

Encapsulation of in vitro derived nodal segments of patchouli (Pogostemon cablin Benth.) was done successfully by employing sodium alginate gel. Among various concentrations of sodium alginate tried to optimize the strength of the bead, 4% sodium alginate produced firm beads and showed the highest percentage of shoot emergence (73.3%). The best storage temperature was found to be 25°C. The encapsulated beads retained regeneration potentiality up to 6 months and later gradually declined. Browning and loss of regeneration was more after 9 months. Various growth regulating factors (6- benzyl adenine, kinetin, coconut water and tomato juice) at different concentrations were tested for their conversion frequency of encapsulated buds. Murashige and Skoog media supplemented with 2.22 µM/l 6- benzyl adenine showed the highest conversion percentage (91.1%) followed by, 10% coconut water (85.4%). Plants retrieved from the encapsulated buds were rooted on half strength Murashige and Skoog basal medium and acclimatized successfully in the soil. This technology can be adopted for ex situ germplasm conservation of elite plants of patchouli.   Key words: Conversion frequency, germplasm conservation, growth regulators, encapsulated buds, patchouli.