tailieunhanh - Báo cáo khoa học: "Effects of sodium chloride salinity on root and respiration in oak seedlings"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Effects of sodium chloride salinity on root and respiration in oak seedlings. | 41 Ann. For. Sci. 56 1999 41 17 Inra Elsevier Paris Original article Effects of sodium chloride salinity on root growth and respiration in oak seedlings Daniel Epron Marie-Laure Toussaint Pierre-Marie Badot Equipe sciences végétales Institut des sciences et des techniques de 1 environnement université de Franche-Comté pole universitaire BP 427 25211 Montbéliard cedex France Received 3 February 1998 accepted 23 April 1998 Abstract - Root and shoot biomass of oak seedlings were reduced after 9 days of watering with a nutrient solution containing either 50 or 250 mM NaCl. Both moderate and high salinity treatment strongly altered root elongation. In contrast specific respiration of roots was unaffected by the moderate salinity treatment while it was reduced by 62 after 9 days of watering with a nutrient solution containing 250 mM NaCl. Na content strongly increased in all plant tissues with increasing NaCl concentration in the nutrient solution. Na contents in leaves and in twigs were lower than in roots at 50 mM NaCl in the nutrient solution while they were similar at 250 mM. Prevention of Na translocation in shoot in moderately stressed oak probably requires extra energy which may be provided by an increase in maintenance respiration. At higher salinity 250 mM root respiration was strongly inhibited which might explain the inability of severely stressed oak seedling to prevent Na translocation to the shoot. An increase in the respiratory cost for maintenance for active ion transport and or for growth processes in oak root encountering sodium chloride salinity is therefore consistent with the occurrence of a high rate of root respiration while growth rate was reduced. Inra Elsevier Paris. growth oak respiration I root salinity Resume - EfTets de la salinité NaCl sur la croissance et la respiration des racines de semis de chêne. La biomasse racinaire et aérienne de semis de chêne est réduite après 9 j d arrosage avec une solution nutritive contenant 50 OU 250 mM de .