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Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Stratifying, partially redrying and storing Douglas-fir seeds effects on growth and physiology during germination. | Ann. Sci. For. 1985 42 4 371-384 Stratifying partially redrying and storing Douglas-fir seeds effects on growth and physiology during germination Marlene DE MATOS MALAVASI Susan G. STAFFORD and D.p. LAVENDER Department of Forest Science Oregon State University Corvallis OR 97331 U.S.A. Summary Douglas-fir Pseudotsuga menziesii Mirb. Franco seeds collected from a coastal and an interior source in Oregon were stratified at 45 p. 100 moisture content MC and then redried to 35 or 25 p. 100 MC and or stored for 1 or 3 months so that the complex interactions among stratification redrying and storage and their impacts on seed vigor and resultant seedling growth could be investigated. Stratified whole seeds and seed parts were hydrated to different degrees. Redrying stratified seeds to 35 p. 100 MC did not affect MC of embryos or gametophytes but redrying to 25 p. 100 MC reduced MC of all seed structures. Three months of storage did not alter moisture distribution within seeds. Stratification reduced the germination percentage of interior-source seeds but hastened germination speed for seeds from both sources. Redrying stratified seeds to 35 and 25 p. 100 MO increased seed.vigor and seedling length and dry weight remarkably a response similar to the invigorating effect reported to improve seed performance for other types of plants Storing stratified seeds without redrying them for 1 or 3 months generally reduced seed vigor as reflected by germination speed and seedling length and dry weight yet redried seeds stored no better than nondried. Levels of biochemical compounds studied were strongly correlated with germination speed. Results suggest that it would be advantageous to redry seeds to a range of 25 to 35 p.100 MC directly before sowing to produce vigorous seedlings or allow expression of stratification benefits. 1. Introduction Stratification treatment moist chilling is a commonly used technique for overcoming dormancy in seeds of many temperate-zone species. However
