Garjan （Dipterocarpus turbinatus Gaertn. F） is a highly ectomycorrhizal tree species growing in hilly areas of Bangladesh. The horizontal distributions ofectomycorrhizas （ECM） in different distances （1, 2, 3 ＆ 4...Garjan （Dipterocarpus turbinatus Gaertn. F） is a highly ectomycorrhizal tree species growing in hilly areas of Bangladesh. The horizontal distributions ofectomycorrhizas （ECM） in different distances （1, 2, 3 ＆ 4m） from the tree base were determined in 5, 10 and 20-year-old D. turbinatus plantations of Chittagong University Campus （CUC） in 2003, The ECM infection （%） in roots was counted at three hill positions （top, mid and bottom） for each of the plantations. Samples of 1000 cm^3 rhizosphere soil were collected from underneath the trees at different horizontal distances. The percentage of infection at different distances and hill elevations varied considerably. In 5 and 10-year-old plantations, the occurrence of infection （%） was rapidly declined with increasing distances, while in 20-year-old plantation, the infection increased sharply with increasing distances from the tree base. The highest infection （81.33%） was found at 4 m distance from the tree at bottom hill in 20-year-old plantation and the lowest （55.33%） at the same distance at the top of the hill in 5-year-old plantation.展开更多
文摘Garjan （Dipterocarpus turbinatus Gaertn. F） is a highly ectomycorrhizal tree species growing in hilly areas of Bangladesh. The horizontal distributions ofectomycorrhizas （ECM） in different distances （1, 2, 3 ＆ 4m） from the tree base were determined in 5, 10 and 20-year-old D. turbinatus plantations of Chittagong University Campus （CUC） in 2003, The ECM infection （%） in roots was counted at three hill positions （top, mid and bottom） for each of the plantations. Samples of 1000 cm^3 rhizosphere soil were collected from underneath the trees at different horizontal distances. The percentage of infection at different distances and hill elevations varied considerably. In 5 and 10-year-old plantations, the occurrence of infection （%） was rapidly declined with increasing distances, while in 20-year-old plantation, the infection increased sharply with increasing distances from the tree base. The highest infection （81.33%） was found at 4 m distance from the tree at bottom hill in 20-year-old plantation and the lowest （55.33%） at the same distance at the top of the hill in 5-year-old plantation.
