Arachis hypogaea Plant Recovery Through in Vitro Culture of Peg Tips1

Abstract

Abstract In vitro culture of embryos in Arachis is necessary to recover interspecific hybrids which otherwise abort soon after fertilization. The objective of this research was to develop in vitro techniques to promote proembryo development so that plants can be recovered. Aerial peg tips consisting of embryos, ovules, and peg meristem of Arachis hypogaea L. cv. NC 6, were collected 7, 10, and 14 d after self-pollination. Peg tips were cultured in the dark on combined MS and B5 media with NAA, GA3 and 6-BAP for 90 d. The effects of plant growth regulators on in vitro reproductive traits, including peg elongation, callus and root production, pod formation, ovule and embryo development were variable. Results indicated that 10-d-old peg tips, which contained eight-celled proembryos, had more embryo development and pod formation than 7- and 14-d-old peg tips. Medium with 4 mg L-1 NAA and 0.5 mg L-1 6-BAP suppressed in vitro development of pods, ovules and embryos and induced large amounts of callus. Media with lower concentrations of NAA, GA3, and 6-BAP caused development of more and larger pods and ovules. The development of young embryos from proembryos was observed and mature seeds were obtained by an in vitro one-step process. Peanut plants were obtained both from in vitro-recovered embryos and from mature seeds.