title: Production of embryogenic callus from nonembryonic explants of Norway Spruce Picea abies (L.) Karst.
abstract: Callus has been induced on needle and bud explants from 2, 6 and 26 year old Picea abies (L.) Karst, trees. Seventy seven percent of the needle explants from the youngest material was productive compared to 0.2% for the old tree. New embryogenic sections appeared in the non-embryogenic callus derived from 2, 6 and 26 year old trees after prolonged culture and was promoted by the use of an established embryogenic callus line in a nurse culture system.
authors.affiliation: Unilever Research, Colworth House, MK44 1LQ, Sharnbrook, Bedford, UK.
authors.forename: R J
authors.initials: RJ
authors.lastname: Westcott