Abstract: TRU system was used to scan the roots of different diameter classes of Camellia szechuanensis Chien in Nanshan Botanical Garden at different distances from tree trunks. The results showed that, with the increase of diameter, the number of roots with diameter ≥ 1 cm gradually decreased at 0.5 m away from the trunk, which was negatively correlated with the diameter and crown width; At the circular section of 0.5 m and 1.0 m, the number of roots increased from 20 to 35, and the distribution range increased from 12.89~56.19 cm to 9.79~59.24 cm. Among them, 78%~85% of the roots with diameter ≥ 1 cm distributed in the soil layer of 20~72 cm, and about 40% of the roots were distributed in the soil layer of 20~40 cm; Taking the trunk as the circle point, within the 90° fan-shaped radius of 5 m, with the increase of the distance from the trunk, the number of roots with the diameter ≥ 1 cm increased gradually, but decreased near the drip line. After digging the soil, it was found that there were many fine roots near the drip line. Although the number of roots whose diameter is more than 1 cm outside the drip line is still increasing, it is difficult to identify them as Camellia roots. Combined with the practice of Camellia tree maintenance, it is suggested that the fertilizer should be applied in furrow along the drip line.

Key words: Camellia szechuanensis Chien, TRU system, root system distribution