Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Carbon and phosphorus relations in and non-mycorrhizal pine seedlings. | 715s Ann. Sci. For. 1989 46 suppl. 715S-717S Forest Tree Physiology E. Dreyer et al. eds. Elsevier INRA Carbon and phosphorus relations in mycorrhizal and non-mycorrhizal pine seedlings . Rousseau and . Reid Department of Forestry University of Florida IFAS Gainesville FL . Introduction Several physiological and developmental responses to mycorrhizal fungus inoculation and applied phosphorus were examined to determine which responses were similar to enhanced phosphorus nutrition and which were more unique to the mycorrhizal association. Materials and Methods Pirns taeda L seedlings initially grown for 10 wk under low p conditions were subjected to a 2x2 factorial design of 2 p levels and Jig g of P with and without inoculation of Piso-lithus tinctorius Pers. Coker and Couch. After an additional 7 wk photosynthesis by all seedlings was measured followed by harvesting and determination of p content and dry weight of foliage stem and roots. Results Non-mycorrhizal seedlings grown under the high phosphorus regime HP-N had a 55 greater photosynthetic rate and 150 greater biomass than did non-mycorrhizal seedlings grown under the low phosphorus regime LP-N Fig. 1a b . Mycorrhizal seedlings grown under the low p regime LP-M also had a 75 greater photosynthetic rate but less than 30 greater biomass than did the LP-N seedlings. Mycorrhizal seedlings grown under the high phosphorus regime HP-M showed no difference in photosynthetic rate over the HP-N seedlings. However HP-M seedlings had 12 less biomass than HP-N seedlings. The phosphorus content and foliar and fine-root p concentrations were respectively 8 4 and 2 times greater in HP-N than in LP-N seedlings Fig. 1c d e . LP-M seedlings showed similar but less dramatic increases over the LP-N seedlings in p content and foliar p concentration. However there was a substantial increase in the fine-root p concentration of the LP-M over the LP-N seedlings even exceeding levels of the HP-N seedlings. For .
