CHANGING CARBOHYDRATE PARTITIONING IN 6-YEAR-OLD CONIFEROUS TREES AFTER PROLONGED EXPOSURE TO CEMENT DUST

摘要

Two-year-old seedlings of Picea abies L. P. glauca L. P. mariana L. Pinus sylvestris L. and Pseudotsuga menziesii L. were planted in a sample plot influenced by high concentrations of cement dust, and in an unpolluted (control) area in 1990. In 1994, the six-year-old trees were dug up in the pre-bud-break period. A comparative analysis of soluble sugars (glucose, fructose, sucrose, maltodextrines), starch and hemicelluloses contents was carried out and the changes in carbohydrate partitioning were estimated. A decrease in the total content of soluble sugars, mainly of glucose, fructose and maltodextrines, was observed in polluted trees, especially in roots, stems and buds, while the sucrose content increased in different organs. Fluctuations in glucose and fructose contents in roots were in good correlation with these sugars in needles and maltodextrines in stems and shoots. Changes in starch and hemicellulose partitioning between different organs of trees were modest and their directions were highly dependent on species. [References: 42]