Standardization of in vitro multiplication technique for Areca concinna Thwaites, an endangered palm species for its conservation and utilization

Abstract

Areca concinna Thwaites (Arecaceae) is an endangered plant species endemic to South-Western Sri Lanka and distributed primarily in Sri Lanka, India, and Southeast Asia. This palm was listed under endangered plants species by IUCN (The International Union for Conservation of Nature) due to habitat loss. Clonal propagation is essential for conservation and maintenance of this endangered species. In an effort to conserve this plant species, a protocol was developed for clonal multiplication of A. concinna Thwaites. Immature inflorescence, immature embryos, and mature embryos were tested for callogenesis and subsequent somatic embryogenesis in M72 basal medium supplemented with the auxins 2,4-D and picloram. Of the three explants, somatic embryos were obtained only from mature embryos. Callus multiplication and somatic embryo formation in M72 basal medium supplemented with 2,4-D were found to be better over picloram media. Serial transfer of explants from higher to lower concentrations was essential for sustaining the multiplication of callus as well as for induction of somatic embryos. Somatic embryos grown in Y3 or 1/2 Y3 basal medium supplemented with 1.0 mg L⁻¹ BAP, 0.5 mg L⁻¹ NAA, and 0.25 mg L⁻¹ IBA exhibited shoot initiation and plantlet development. This protocol has its application in rapid multiplication of A. concinna Thwaites palms thereby enhancing the possibility of conservation of the endangered palm.