English

Abstract

Nitrate is an important factor affecting the safety of vegetables. How to reduce the content of nitrate has become a common concern in vegetable production. The effect of dicyandiamide (DCD) on physiology and nitrate accumulation was studied using hydroponic cherry radish as material, in order to lay a foundation for production radish with better quality. The results showed that DCD treatment increased the content of chlorophyll-a (Chl-a), carotenoid (Car) and anthocyanin while decreased Chl-b content. Treatment with 3% DCD reduced the nitrate content while 6% DCD increased it compared with the control. Furthermore, higher the nitrate content, lower was the nitrate reductase (NR) activity, which suggested that there was a negative correlation between nitrate content and NR activity in leaves of cherry radish. The stomatal density of leaves was almost the same between 3% DCD and the control, while it was lower under 6% DCD. To sum up, DCD significantly affected the photosynthetic pigment content of cherry radish, which may affect the photosynthesis. DCD also reduced the nitrate accumulation as well as increased the Car and anthocyanin content. These findings suggested that application of DCD may be an approval measurement to improve safety and appearance quality of hydroponic cherry radish. © 2022 Friends Science Publishers