The problems in acclimatisation of in vitro multiplied plants of Lavandula stoechas L. under field conditions

Abstract

France lavender (Lavandula stoechas L.) family Lamiaceae is an important plant widely grown in many parts of Europe Africa, USA and Australia. Every year, a large foreign exchange is earned by essential oils export by many countries. Acclimatisation of in vitro grown plants is very difficult needing understanding the growth habit and factors including the root apparatus of the plants to be acclimatised, surrounding temperature, humidity, soil template etc. responsible for plant growth under in vitro and ex vitro conditions. As the in vitro cultured plants are very sensitive to each of these; even a very small lag in the look after of the tissue cultured plants; lead to damage and death. In line with this, the study aimed to acclimatise in vitro regenerated plantlets of L. stoechas under field conditions. Initially the shoot regeneration was induced using variable concentrations of BAP-NAA on stem node explants followed by rooting on MS medium containing IBA. Thereafter, the plants were transferred to fields after a difficult procedure of acclimatisation and optimisation using hydropnic culture, sterilised sand, clay, peat and their mixture suggesting that every step after rooting, transfer of the plantlets to pots, acclimatisation and transfer to fields is very important. The study reports difficulties, problems and techniques to handle these substrates and their transfer to soil in open fields. The acclimatised plants are flourishing and growing well under Mediterranean continental type field conditions. Key word: Lavandula stoechas, in vitro regeneration, Acclimatisation.