Effect of ?-naphthaleneacetic acid and sucrose levels on the development of cultured embryos of coconut

Abstract

Mature coconut embryos were germinated in a modified Murashige and Skoog medium and then cultured on BMY3 medium incorporating sucrose in the range of 4 to 8%. α-Naphthaleneacetic acid (NAA) was added into the medium at concentrations ranging from 0 to 800 μM for periods of 4 to 24 weeks. Application of NAA for 4 weeks stimulated shoot growth, whereas application periods greater than 4 weeks had no significant effect. NAA in the range of 100–300 μM stimulated elongation of the primary root and the optimum concentration increased with increases in sucrose levels. Production of adventitious roots was stimulated by the addition of NAA with levels of 200 μM and above being the most effective. Increasing the sucrose concentration from 4% through to 8% stimulated root elongation in the absence of NAA and inhibited shoot growth whether NAA was present or absent.