Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí lâm nghiệp đề tài:"Daylength, temperature and fertilization effects on desiccation resistance, cold hardiness and root growth potential of Picea mariana seedlings" | Ann. For. Sci. 60 2003 307-317 INRA EDP Sciences 2003 DOI forest 2003022 307 Original article Daylength temperature and fertilization effects on desiccation resistance cold hardiness and root growth potential of Picea mariana seedlings Stephen J. COLOMBOa Chris GLERUMat and D. Paul WEBBb a Ontario Forest Research Institute Ontario Ministry of Natural Resources 1235 Queen Street Sault Ste. Marie Ontario P6A 2E5 Canada b Great Lakes Forestry Centre Canadian Forest Service Sault Ste. Marie Ontario Canada Received 17 January 2002 accepted 19 August 2002 Abstract - Picea mariana Mill. . seedlings were hardened for overwintering under four regimes. In three regimes seedlings were kept inside a heated greenhouse for 11 weeks during and after dormancy induction August to mid-November with either 1. Natural daylengths 46 31 N and warm temperatures of 20 C or more NDW 2. As 1 but fertilized NDWF or 3. As 1 but with shortened daylengths SD . In the fourth regime OD seedlings were hardened outside at naturally declining temperatures and daylengths without fertilizer. Seedlings hardened in any warm temperature treatment had buds with more needle primordia and shoots more resistant to desiccation than OD seedlings. Initially cold hardiness tended to be greatest in SD seedlings. As hardening progressed OD seedlings became equally cold hardy to SD. In late November when all trees were outside NDW seedlings were usually least cold hardy. Spring root growth potential was least in OD seedlings. cold hardiness desiccation needle primordia transpiration water potential Résumé - Effets de la longueur du jour de la température et de la fertilisation sur la resistance à la dessiccation et au froid et au potentiel de croissance de plants de Picea mariana. On a soumis des semis de Picea mariana Mill. à quatre traitements pour les endurcir au froid en vue de la période hivernale. Pour trois traitements les plants ont été installés sous serre chauffee pendant 11 semaines pendant
