Effects of Biochar-based Organic Fertilizer on Accumulation of Total Flavonoid Contents in Dandelion

In order to study the effects of biochar-based organic fertilizer on the accumulation of the total flavonoid contents in dandelion after sowing,the experiment applied four levels of treatments of carbon-based organic fertilizer (0.15,0.30,0.45,and 0.60 kg·m-2),and the base fertilizer that only applied conventional chemical fertilizer was used as the control.The total flavonoid contents and physiological indices of dandelion in different growth periods were determined.The results showed that the accumulation of the total flavonoid contents in leaves and roots of dandelion improved significantly by applying biochar-based organic fertilizer (0.15,0.30,0.45,and 0.60 kg·m-2),with the highest total flavonoid occurred in the 0.45 kg·m-2 biochar-based organic fertilizer treatment.Along with dandelion growing,the total flavonoid contents in leaves were first elevated,and then decreased,with the maximum reached at 95 days after sowing （anthesis）.While the total flavonoid contents in roots were elevated constantly.The total flavonoid contents accumulation in dandelion were positively correlated with net photosynthetic rate,stomatal conductance,transpiration rate,soluble sugar content,soluble protein,nitrate nitrogen,and available potassium,while negatively correlated with intercellular CO2 concentration.