Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Effect of soil temperature upon the root growth and mycorrhizal formation of white spruce (Picea glauca (Moench) Voss) seedlings grown in controlled environments. | 750s Ann. Sci. For. 1989 46 suppl. 750S-753S Forest Tree Physiology E. Dreyer et al. eds. Elsevier INRA Effect of soil temperature upon the root growth and mycorrhizal formation of white spruce Piceaglauca Moench Voss seedlings grown in controlled environments L. Husted and . Lavender Department of Forest Sciences University of British Columbia Vancouver Canada Introduction The effects of root zone temperature and mycorrhizal formation on the shoot and root morphology of white spruce seedlings were examined in a controlled environment. A companion study evaluated effects of root zone temperature upon root growth at different stages of seedling growth throughout the year. Materials and Methods 3 mo old dormant container-grown white spruce seedlings from a northern British Columbia seed source were inoculated with 1 Hebe-loma crustiliniforme 2 Thelephora terrestris 3 forest floor collected from a vigorous northern spruce plantation 4 peat vermiculite collected from mycorrhizal mainly E-strain and MRA container nursery stock and 5 nothing control . After inoculation the seedlings were grown at 3 root zone temperatures 5-8 15-17 and 25-29 C in a growth cabinet programmed for 19-21 C air temperatures 70-90 RH and an 18 h photoperiod. The root zone temperature and inoculation treatments were facto-rially arranged to give 15 treatment combinations. Seedling height and caliper were measured at the initiation of treatment 5 and 15 wk later. At each sample date a subsample of seedlings was harvested to estimate needle stem and root dry weight length of long roots short root development and mycorrhizal formation. Mycorrhizal formation was estimated by scanning the surface of the whole root plugs at 12-40X magnification and checking whole mounts at 500-1 OOOx Danielson and Visser 1984 . Treatment means for the 15 wk sample were compared by 2-way least squares analysis of covariance using SYSTAT. Initial caliper the covariate did not interact significantly with the .
