# Characteristics of Growth, Photosynthesis, C/N Ratio, and Antioxidant Capacity in the Seedling Stage of Aquilaria sinensis ‘Qinan’

## TL;DR

This study compares the growth and biochemical characteristics of Aquilaria sinensis ‘Qinan’ and regular A. sinensis seedlings during their early development.

## Contribution

The study reveals unique growth and metabolic traits of A. sinensis ‘Qinan’ that may aid in its ability to form agarwood.

## Key findings

- A. sinensis ‘Qinan’ has a higher net photosynthetic rate in mature leaves compared to A. sinensis.
- A. sinensis ‘Qinan’ contains more secondary metabolites and shows stronger antioxidant capacity.
- A. sinensis exhibits larger leaf area and faster growth rate than A. sinensis ‘Qinan’.

## Abstract

In this study, Aquilaria sinensis ‘Qinan’, a strain of A. sinensis that easily forms agarwood, was selected and propagated by grafting seedlings. Existing research has mainly focused on the characteristics of agarwood formation, but little attention has been paid to the growth characteristics of A. sinensis ‘Qinan’. In this study, the growth rate, photosynthetic capacity, leaf size, carbon and nitrogen contents, and antioxidant capacity were evaluated during the early growth stage in A. sinensis ‘Qinan’ and A. sinensis grafted seedlings. Compared with A. sinensis, A. sinensis ‘Qinan’ exhibited higher net photosynthetic rate (9.2 μmol m−2 s−1 in A. sinensis ‘Qinan’ and 7.8 μmol m−2 s−1 in A. sinensis) in the mature leaf. There were higher contents of secondary metabolites such as flavonoids and phenols, with stronger antioxidant capacity in A. sinensis ‘Qinan’. Larger leaf area (43.9 cm2 in A. sinensis and 30.1 cm2 in A. sinensis ‘Qinan’), higher nitrogen content (24.9 mg kg−1 in A. sinensis and 23.7 mg kg−1 in A. sinensis ‘Qinan’) in young leaves, faster growth rate, and larger biomass were observed in A. sinensis. The results indicate that differences exist in nutrient distribution during the growth process of A. sinensis ‘Qinan’ and A. sinensis, with more substances being used to synthesize defensive secondary metabolites in A. sinensis ‘Qinan’.