In vitro propagation of bijasal (Pterocarpus marsupium Rxob.) through tissue culture

Abstract

The present investigation was carried out at the College of Forestry, Vellanikkara during 1991 – 93 with an objective of making a protocol for micropropagation of bijasal (Pterocarpus marsupium). Axillary buds obtained from mature trees were used as the explants. During the study it was found that nodal segments of size about 1 cm was ideal as the explants. Prophylactic spraying of mother trees with mixture of Bavistin and Indofil m-45 coupled with surface sterilization of explants with 0.1 per cent mercuric chloride for 10 minutes could control culture contamination to the greatest extent. However, systemic bacterial infection in explants could not be controlled. Murashige and Skoog (MS) medium was noted to be suitable for primary culture establishment. Woody plant medium (WPM) supplemented with 2.0 ppm kinetin and 0.1 ppm IAA was the best for inducing multiple shoots from primary explants. The various growth regulator combinations however, failed to induce leaf morphogenesis in shoots. Among the various media additives tested, CCC had a beneficial role in leaf production in culture. Case in hydrolysate, adenine sulphate, coconut water, silver nitrate, cobalt chloride and activated charcoal were the other additives tried without having any significant beneficial effect on culture of bijasal. Sucrose at two per cent or three per cent sucrose with one per cent maltose were noted to be ideal carbon sources in culture. Semi – solid medium having 0.8 per cent agar was found to be best for culturing the nodal segments. The culture did not show any difference in growth in a range of pH from 5 to 6. An illumination of 2000 Lux light was most ideal for incubating the cultures. All attempts to establish continuous cultures failed due to the sudden loss of morphogenetic potential of cells on culture.