Description

Abstract: Interspecific hybridization in Arachis is restricted by early embryo abortion for many cross-combinations. Rescue of young embryos in vitro within a week after fertilization is necessary to recover these embryos before they abort. Peg tips, with the ovule and embryo tissues, of A. hypogaea L. cv. ‘NC 6’, were cultured to compare ovule growth, callus production and peg elongation. Tissues were collected 1, 2, 3 and 4 d after self-pollination, after which peg meristems were removed from half the pegs and cultured on five media combinations. One-day-old pegs had significantly (P = 0.01) more ovule growth than older tissues. Presence of the meristem had a greater inhibition to ovule growth for 2- to 4-d pegs than for 1-d-old pegs. Significantly more callus was produced on 4-d pegs than younger tissues, and kinetin had the greatest stimulatory effect on callus. Elongation of pegs with the meristem attached was observed most often in media with high sucrose levels. The observations indicate that very young ovules can be grown in vitro, and techniques may be applicable to rescue of young embryonic tissues of Arachis.