Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Micropropagation and restricted-growth storage of adult oak. | Ann Sci For 1993 50 Suppl 1 323S-329S Elsevier INRA 323s Original article Micropropagation and restricted-growth storage of adult oak genotypes K Gebhardt u Fruhwacht-Wilms H Weisgerber Forschungsinstitut fur Schnell Wachsende Baumartin Prof Oelkersstr 6 D-3510 Hann Munden Germany Summary The winter buds of stump sprouts epicormic shoots and grafts from adult pedunculate and sessile oak trees proved to be valuable sources of shoot tips. Established shoot-tip cultures exhibited long-term viability. Proliferation and vitality of new shoots was best from the base part of shoots if the callus tissue remained at the basal stem segment. Aged callus cells are involved in the process of xylogenesis which inhibits organogenesis. Root initiation depends upon optimum auxin supply but auxin causes side effects on shoot elongation and callus-cell proliferation. Shoot-tip necrosis was prevented if shoots with induced roots were subcultured on cytokinin-containing medium. The labor and expense of repeated subculture can be reduced by lowering growth temperature to 15 10 or 4 C. By using abscisic acid - 10 pM and applying polyethylene glycol mol wt 4000 at concentrations of 4 and 8 the inhibition of biomass accumulation will continue over 2 regular subculture periods on media without growth retarding substances. Quercus I in vitro culture bud temperature conservation Resume Micropropagation et conservation de chênes âgés sous conditions limitant la croissance. Les bourgeons de rejets de souche de pousses épicormiques et de greffes issus de plants âgés de chêne pédonculé et sessile constituent un excellent materiel pour la culture de segments de tiges. Ils manifestent une longue viabilité. Les meilleures viabllité et proliferation ont été obtenues sur du materiel prélevé à la base des segments. Les cellules âgées des cals sont impli-quées dans la xylogenèse qui inhibe 1 organogenèse. L initiation des racines depend d un niveau optimal d auxines mais la production d auxine a des
