title: Somatic embryogenesis in loblolly pine (Pinus taeda L.): improving culture initiation with abscisic acid and silver nitrate.
abstract: Loblolly pine ( Pinus taeda L.) culture initiation was improved by the addition of abscisic acid (ABA) (3.7 micro M), silver nitrate (20 micro M), and guanosine 3',5'-cyclic monophosphate, 8-bromo-, sodium salt (10 micro M) to the medium and by raising cytokinin levels in the presence of 50 mg/l activated carbon (AC). Basal medium contained modified 1/2-P6 salts, 50 mg/l AC, Cu and Zn added to compensate for adsorption by AC, 1.5% maltose, 2% myo-inositol, 500 mg/l casamino acids, 450 mg/l glutamine, 2 mg/l alpha-naphthaleneacetic acid (NAA), 0.55 mg/l 6-benzylaminopurine (BA), 0.53 mg/l kinetin, and 2 g/l Gelrite. Across 32 open-pollinated families initiation ranged from 0 to 53.4%, with an average of 17.9%. Further optimization of cytokinins to 0.63 mg/l BA and 0.61 mg/l kinetin along with the removal of ABA maintained initiation at 18.2% across 19 families. Survival of 2001 new initiations was tracked for 4-6 months. Survival averaged 28.8%. A test of 68 new initiations tracked closely for 4 months demonstrated that at least 80% of the cultures lost did not grow after transfer to the multiplication media, suggesting that many new initiations abort during the initiation process.
authors.affiliation: Institute of Paper Science and Technology, 500 10th Street, Atlanta, GA 30318, USA. Jerry.Pullman@ipst.edu
authors.forename: G S
authors.initials: GS
authors.lastname: Pullman
authors.forename: K
authors.initials: K
authors.lastname: Namjoshi
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D002244:Carbon / Q000494:pharmacology; D003470:Culture Media / Q000494:pharmacology; D046508:Culture Techniques; D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000494:pharmacology; D003583:Cytokinins / Q000494:pharmacology; D018525:Germination / Q000187:drug effects; D041603:Pinus taeda / Q000187:drug effects / Q000196:embryology* / Q000254:growth & development; D012639:Seeds / Q000187:drug effects / Q000196:embryology* / Q000254:growth & development; D012835:Silver Nitrate / Q000494:pharmacology*
chemical_list: D003470:Culture Media; D003583:Cytokinins; C016276:8-bromocyclic GMP; D000040:Abscisic Acid; D002244:Carbon; D012835:Silver Nitrate; D006152:Cyclic GMP