35 ▣0-15cm 30 ☐15-30cm 25 20 15 10 5 0 <3 4-7 8-10 11-20 >20 Plant Age(years) Colonization generally increased with increasing plant age with highest levels of colonization in roots from the upper 15 cm of soil in younger plants and the highest levels of colonization in roots at the 15-30 cm depth in older plants. 菌根侵染率随着树龄的增加而提高 果树专业须去生漂程yao2果树专业硕士生课程-yao2 Colonization generally increased with increasing plant age with highest levels of colonization in roots from the upper 15 cm of soil in younger plants and the highest levels of colonization in roots at the 15-30 cm depth in older plants. 菌根侵染率随着树龄的增加而提高