Effects of NO on growth characteristics of Aquilaria sinensis seedlings under acid-aluminum stress

Using potted plants completely random design，the effect of NO on the growth of Aquilaria sinensis seedlings under acid-aluminum（ Al） stress was studied. The results showed that A. sinensis seedlings，growth indexes such as seedling height，ground diameter，biomass，stem，specific leaf weight，root growth indices displayed a downward trend after rising first. Concentration below 0.4 mmol/L aluminum solution for Aquilaria sinensis seedling growth had a certain role in promoting，with aluminum concentration increasing，the seedling growth of trees was inhibited. Comprehensive analysis showed that the promotion effect of 0.2 mmol / L of Al was most obvious. When the concentration of aluminum increased to more than 0.4 mmol/L，there was a significant inhibitory effect on A. sinensis seedlings growth，the effect of 0.8 mmol/L aluminum solution was the worst. The addition of 0.1 mmol/L SNP could alleviate the effect of aluminum stress on the inhibition of seedling growth. The results showed that the growth of treatment 7（ 0.2 mmol / L Al，0.1 mmol / L SNP） was the best，plant height，diameter，biomass were 0.69 m，0.48 cm，39.00 g，the total root length，root mean diameter，root surface area，root total volume and root tip number of root system were 3 750 mm，0.805 cm，800 mm2，12.8 cm3 and 6 000. While treatment 5（ 0.8 mmol / L Al，0 mmol / L SNP） obtained the minimum，the plant height，diameter and biomass were 0.28 m，0.18 cm and 26.30 g， respectively，the root indexes were 1 380 mm，0.570 cm，320 mm2 and 6.00 cm3，2 550.