Tissue culture studies and molecular characterization of Pongamia (Pongamia pinnata (L.) Pierre), an oil producing tree legume

Abstract

Pongamia pinnata (L) Pierre (Syn: Pongamia glabra. Vent), an oil producing tree legume, popularly known as Karanja, is the most widely available non-edible oil tree in India. This multipurpose tree species is well adapted for various agro climatic conditions and is one of the most extensively chemically investigated plants. Potential of the seed derived oil of Pongamia as a substitute for diesel is recognized and often identified as quotBio-dieselquot. A large number of bioactive compounds have been isolated and characterized from various parts of this tree (flavonoids, furanoflavonoids), which has many industrial and medicinal uses. Pongam oil resembles groundnut oil in its fatty acid composition. However, due to presence of substances like Karanjin and Pongamol, the oil is non-edible. Biotechnological approaches offer the potential to alter qualitative and quantitative improvement in the products obtained from trees. By subjecting to these approaches, Pongamia can serve as a source of high quality fuel and raw material for industries. Raising plantations of clonally propagated, high seed yielding trees will contribute to increased seed production. These plantations will also serve the purpose of seed orchard for production of superior quality seeds. Pongamia tree can also be exploited as an alternate source of edible oil by silencing the related genes, which cause production of undesirable substances. From the existing literature it is apparent that there is a lot of scope for genetic modification of Pongamia for which there is need to develop a reproducible in vitro regeneration system. There is no literature on in vitro regeneration or tissue culture studies in this species. Keeping in view, the recalcitrant nature of leguminous tree species, standardization of protocols for in vitro morphogenesis remains a challenging proposition. To date, there is no literature available regarding the molecular scaffold of this tree.