Somatic embryogenesis in Cymbopogon pendulus and evaluation of clonal fidelity of regenerants using ISSR marker

摘要

An efficient plant propagation system through somatic embryogenesis was established in Cymbopogon pendulus, an aromatic grass followed by analysis of genetic status of regenerants using ISSR markers. Optimum embryogenic callus induction was observed on MS basal medium supplemented with 13.57oM 2,4-dicholorophenoxyacetic acid (2,4-D) with 8.88oM Ne-benzyladenine (BA). Subsequent culturing of embryogenic calli on MS medium containing 4.52oM 2,4-D and 8.88-13.32oM BA gave maximum number of somatic embryos. Addition of coconut water (CW) promoted induction, growth and differentiation of callus and somatic embryogenesis. Further development of embryos into plantlets was achieved on MS medium supplemented with lower concentration of biotin and calcium pantothenate (CaP) along with BA (4.44-13.32oM) and kinetin (2.32-4.65oM). The root meristems were established on half strength MS medium containing 2% sucrose and 2.46-9.84oM Indole3-butyric acid (IBA) and successfully established in soil with 77.8% survival rate in field condition. Thirteen randomly selected regenerated clones were screened using six ISSR primers. Nine clones produced similar monomorphic amplification profiles while remaining clones showed minor variation with absence of certain parental bands and appearance of unique band. Majority of the regenerants maintained genetic fidelity with the generation of few variants as evidenced from similarity matrix estimates using Nei Li's coefficient of similarity data.