title: Plant regeneration from mesophyll and suspension protoplasts of Silybum marianum.
abstract: Mesophyll protoplasts of six lines of Silybum marianum were enzymatically isolated from young leaves, embedded in sodium alginate, and cultivated in KM-medium. Division frequencies observed after ten days were strongly influenced by the protoplast density. When 5 x 10 (4)/ml protoplasts were plated, division frequencies of about 35% were obtained, with a protoplast population density of 1 x 10 (5)/ml division frequencies of about 75% resulted. Plant regeneration experiments undertaken with the protocalluses on medium containing BAP led to shoot formation in only two lines with regeneration frequencies of less than 1% in one (M 24) and up to 7% in a second line (M 2), respectively. However, when the protocalluses from line M 2 were treated with thidiazuron (TDZ) in a first culture step, and with BAP in a second step, the shoot formation frequency rose to 22%. Shoots were rooted on hormone free MS agar medium and transferred into soil where plants grew to maturity. Similar results were obtained when protoplasts of the line M 2, isolated from a suspension culture, were cultivated.
authors.affiliation: Institut für Angewandte Genetik, Freie Universität Berlin, Albrecht-Thaer-Weg 6, D-14195 Berlin, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Hetz
authors.forename: E H
authors.initials: EH
authors.lastname: Perales
authors.forename: R
authors.initials: R
authors.lastname: Liersch
authors.forename: O
authors.initials: O
authors.lastname: Schieder