Optimization of growth regulators in organogenesis of Bletia purpurea (Lam.) using response surface design and genetic evaluation

Abstract

This paper reports the optimal concentrations of indol acetic acid (IAA) and benzylaminopurine to stimulate morphogenetic induction Bletia purpurea (Lam.) and the application of random amplification of polymorphic deoxyribonucleic acid (DNA) (RAPD) for genetic evaluation of micropropagated plantlets. Organogenesis was induced from B. purpurea (Lam.) explant pseudobulbs in Murashige and Skoog (MS) medium at full ionic strength and supplemented with 20 g/l sucrose, 2 g/l activated carbon and 2.2 g/l Gel Rite. Optimum growth regulator concentrations were determined by response surface design, according to Box-Benhken. At 15 days after morphogenic induction was observed, direct shoots formation on the explant was attained, and optimum concentrations for the greatest number of shoots was 1.8 mg/l Indol acetic acid and no benzylaminopurine. Comparison of RAPD genetic profiles for mother plantlets and regenerated daughter plantlets showed no changes in the genome based on the oligonucleotides used. The conditions applied in this protocol produces plantlets which maintain the genetic traits of the first generation.

Keywords: Genetic evaluation, polymerase chain reaction (PCR), random amplification of polymorphic DNA (RAPD) analysis, Bletia purpurea, pseudobulbs, direct organogenesis, response surface design, in vitro