Selection of mutants obtained by gamma ray irradiation and analysis of genetic variation using RAPD markers in Acorus calamus L.

Abstract

Acorus calamus is a perennial and medicinal hydrophyte belonging to the family Acoraceae. Irradiation of gamma ray was carried out to obtain mutants of A. calamus due to their limited genetic variation. In vitro explants of A. calamus were irradiated with various doses (20–500 Gy) of gamma rays and the irradiated explants were subcultured for three cycles (vM3). All these explants were cultured on MS medium (salts and vitamins) with 3% (w/v) sucrose, 0.8% (w/v) agar and 4 mg∙L−1 BA (6-benzyl amino purine). This system was performed to select various mutants such as dwarf and salt toleranct mutants. Four solid dwarf mutants were obtained from 3,844 explants and three salt tolerant mutants were selected among 2,800 explants. In selected mutants, polymorphic bands were obtained by using RAPD analysis with selected 9 random primers. The dwarf and salt tolerant mutants were differentiated as a result of cluster analysis. We obtained four dwarf and three salt tolerant mutants from gamma ray irradiation. We conclude that gamma ray irradiation applied to in vitro culture system is an effective way for inducing exclusive mutantationsof A. calamus and the mutants were cleanly differentiated from the wild-type control through RAPD analysis.