Differences of Tillering and Endogenous Hormone Content of Cunninghamia lanceolata Clones in Different Soil Depth

Taking cuttings and plantlets of Cunninghamia lanceolata'Yang 020' as experimental materials, a pot experiment was conducted to investigate the effects of different soil depths on the tillering of C. lanceolata clones, the differences of indoleacetic acid, gibberellin, cytokinin and abscisic acid in different organs such as branches, leaves, basal phloem and root tip were determined by enzyme-linked immunosorbent assay. The results showed that the tillering ability of C. lanceolata'Yang 020' plantlets was stronger than that of tillering 'Yang 020' cuttage, and the tillering ability of 2 clones decreased with the increase of soil depth. The content of endogenous hormones in the root tip and the branches and leaves was higher under different soil depth treatment; the content of indoleacetic acid and gibberellin in the branches and leaves increased and decreased with the extension of culture time; the content of abscisic acid in the branches and leaves and the root tip was increased under 6 cm soil depth treatment, and the content of cytokinin in the root tip was increased under 9 cm soil depth treatment; there was a very significant negative correlation between clonal tillering and soil depth, and a very significant positive correlation between clonal tillering and gibberellin content. Different depth of buried soil had certain effect on the clonal tillering of C. lanceolata, and the peak of which was in August; the content of endogenous hormones in different organs was one of the main factors affecting the clonal tillering of C. lanceolata.