Morphogenetic induction and organogenic differentiation from foliar explants of Strobilanthes flaccidifolious Nees: a natural dye yielding plant

Abstract

Strobilanthes flaccidifolious is a shrub and its leaf is the source of blue color natural dye used for dying fibers and play important role in handloom industry. During the present investigation, an efficient in vitro regeneration protocol is developed from foliar segments of in vitro sourced plant materials. The first sign of response from the cultured foliar segments was recorded as swelling and curling of leaf segments within 7 days of culture followed by callusing and shoot buds formation within 3-4 wk. Amongst the different plant growth regulators tested, optimum response was recorded on MS medium enriched with 3% sucrose, 6 µM BA while other growth regulators and their concentrations did not support satisfactory morphogenetic response. Under optimum condition ~75% explants responded positively where as many as 9 shoots buds developed per leaf segment. The shoot buds converted into plantlets/micro shoots on MS medium when supplemented with 3 µM Kn where as many as 7.3 shoot buds developed per subculture of 3-4 wk duration. The micro shoots induced roots on MS medium enriched with 3 µM NAA where as many as 14 roots developed per plant within 4 wk times. The well rooted plantlets were transferred in potting mix and maintained in the poly-shed (50% light) for two months before transferring to the field.