In Vitro Reproductive Development of a Diploid Wild Species, Arachis duranensis1

Abstract

Abstract Embryo abortion at an early stage of reproductive development is a major impediment for introgressing germplasm from wild to cultivated species of Arachis by interspecific hybridization. Ovule and embryo culture techniques have been used to rescue aborting hybrid embryos, but increased efficiency and recovery of very young tissues are still needed. The objective of this study was to induce growth and differentiation of A. duranensis proembryos. Seven-, 10-, and 14-d-old peg tips were cultured on a modified basal medium containing MS and B5 media combinations with 16 combination treatments using three growth regulators—1-naphthaleneacetic acid, gibberellic acid, and 6-benzylaminopurine—each at four levels. The results showed that seeds could be obtained in vitro by peg tip culture of four- to 16-celled proembryos. The favorable concentration ranges of growth regulators for pod formation and embryo development were 0.5-2.0 mg/L NAA, 0.05-0.5 mg/L GA3, and 0.05-0.2 mg/L 6-BAP. Over all three selected ages of pegs, the three best combinations of growth regulators resulted in 4.8, 4.7, and 3.5% pod formation, respectively.