Evaluation of genetic variability in in vitro sodium azide-induced Dendrobium ‘Earsakul’ mutants

Abstract

ABSTRACT. In vitro mutagenesis of Dendrobium 'Earsakul' was carried out by incubating the protocorm-like bodies in 0-5 mM sodium azide for 1 h. Twenty-eight putative mutants were evaluated for genetic variability compared to untreated control plants using inter-simple sequence repeat (ISSR) analysis. Polymorphic fragments were produced by 9 of 12 ISSR primers. A total of 173 amplified ISSR fragments varying in size from 140 to 5000 bp were obtained, 39 of which were polymorphic (22.5%). Of the 28 putative mutants, 15 (53.6%) showed altered genetic profiles compared to control and were identified as mutants. These results suggest that sodium azide can be effectively utilized to generate mutants in Dendrobium 'Earsakul', and ISSR provides a powerful tool that allows efficient early detection of these mutants. The identified mutants are currently being multiplied for further evaluation of their horticultural characteristics.

Mutation Induction of Dendrobium ‘Earsakul’ Using Sodium Azide

“…It was found that the polymorphism percentage was higher in this work (34.81%) than that in our previous work (22.54%), suggesting that the polymorphism percentage may vary according to plant population used and indicating the importance of using optimal NaN 3 concentrations for inducing mutation. In both works, ISSR 818 gave high percentages of polymorphism (69.0% in this work and 42.9% in previous work), indicating its usefulness in this orchid species (Wannajindaporn et al, 2014).…”

“…ISSR analysis. Twelve ISSR primers homologous to microsatellite repeats and containing additional selective anchor nucleotides that were developed from the University of British Columbia and which have been used successfully in Dendrobium (Wannajindaporn et al, 2014) were chosen for the analysis. The polymerase chain reaction (PCR) was modified from Baloch et al (2010) and Brown-Guedira et al (2000).…”

“…Mutations can be induced by either radiation or chemical mutagens. The most commonly used chemical mutagens which do not require expensive equipments are ethyl methane sulphonate, pronamide, ethyl nitroso urea, and NaN 3 (Wannajindaporn et al, 2014). NaN 3 is a powerful chemical mutagen that causes point mutation (transitions and transversions), especially AT to CG that can result in amino acid changes, modifying the function of proteins, and altering plant phenotypes.…”

“…NaN 3 is a powerful chemical mutagen that causes point mutation (transitions and transversions), especially AT to CG that can result in amino acid changes, modifying the function of proteins, and altering plant phenotypes. It also induces chromosome aberrations, predominantly translocations, lagging chromosomes, bridges, sticky chromosomes, and polyploidization (Al-Qurainy and Kl a stersk a et al, 1976;Wannajindaporn et al, 2014). The mechanism of NaN 3 is mediated through the production of organic metabolite of azide compound [L-azidoalanine; N 3 -CH 2 -CH(NH) 2 -COOH] (Al-Qurainy and .…”

“…In addition, they have been used in several ornamental plants such as Madagascar periwinkle (Catharanthus roseus (L.) G. Don) (Shaw et al, 2009), dogwood (Cornus spp.) (Shi et al, 2010), chrysanthemum (Chrysanthemum indicum L.) (Palai and Rout, 2011), lily (Lilium longiflorum) (Xi et al, 2012), as well as several orchids including foxtail orchid (Rhynchostylis retusa) (Parab and Krishnan, 2008), spring orchid (Cymbidium goeringii) (Wang et al, 2009b;Yao et al, 2007), jewel orchid (Anoectochilus formosanus Hayata) (Zhang et al, 2010), and Dendrobium (Wang et al, 2009a;Wannajindaporn et al, 2014). Mutations from deletions/duplications or nucleotide changes at the ISSR primer binding sites lead to altered patterns of amplified DNA fragments and allow efficient mutant selections.…”