Somatic embryogenesis in peanut: Influence of growth regulators and sugars

Abstract

Somatic embryogenesis and plant regeneration were induced from immature embryonal axes and immature cotyledons of peanut (Arachis hypogaea L. fastigata type cv JLM-1). Influence of different auxins, cytokinins and sugars on somatic embryogenesis from immature cotyledon explants was also investigated. Among the different auxins tested, 2,4-dichlorophenoxyacetic acid (2,4-d) was most effective, producing the highest frequency of responding cultures and highest average number of somatic embryos per responding culture, while dicamba, picloram, indolepropionic acid, α-naphthaleneacetic acid, 2,4,4-trichlorophenoxypropionic acid and α-naphthoxyacetic acid were also effective for embryogenesis. Indolebutyric acid, indoleacetic acid, p-chlorophenoxyacetic acid and trichlorophenoxyacetic acid were not beneficial. Among the four cytokinins tested, zeatin slightly enhanced the frequency of somatic embryogenesis, while kinetin, 6-γ-γ-dimethylallylaminopurine and benzyladenine were relatively inhibitory. Among the different carbon sources tested, sucrose was the best for embryo induction and at 6% sucrose the highest frequency of responding cultures and average number of somatic embryos per explant were obtained. For inducing embryogenesis from embryonal axes, 2,4-d was more effective than picloram. Highest plant conversion frequency from somatic embryos was obtained in presence of dicamba or NAA and using cotyledon explants.