Abstract:

To study the salt tolerance of cherry radish at germination and seedling stage, and explore the effect of fulvic acid potassium on improving salt tolerance, in this experiment, four NaCl concentration treatments (1.5, 3.0, 4.5 and 6.0 g/L) were used in hydroponics, and 0 g/L was used as control. Two treatment methods were set as adding 0.2 g/L fulvic acid potassium and not adding fulvic acid potassium, to investigate the germination rate, survival rate, morphological index and chlorophyll content of cherry radish. The results showed that with the extension of culture time in salt solution and the concentration increase of culture solution, the rate and extent of survival rate reduction of cherry radish seedlings both increased. The germination rate of cherry radish decreased slightly when the culture solution reached 3.0 g/L, and the dead seedling rate increased with the increase of salt concentration in the hydroponic solution. With the increase of the concentration of hydroponic solution, the root length, hypocotyl length, root-shoot ratio and dry matter weight of cherry radish were all inhibited to different degrees. At the same concentration of hydroponic solution, compared with the treatment without fulvic acid potassium, the germination rate of the treatments with fulvic acid potassium increased by 3.4%, 3.4%, 2.4%, 2.4% and 3.6%, respectively, and the time of the emergence of dead seedlings was delayed, but the dead seedling rate of the treatments of 1.5, 3.0 and 4.5 g/L increased by 188.9%, 21.2% and 8.1%, respectively. In the control treatment, the addition of fulvic acid potassium significantly increased the chlorophyll-a content, carotenoid content, root length and dry matter weight of cherry radish (P<0.05). The salt tolerance of cherry radish at germination stage was greater than that in the seedling growth stage, fulvic acid potassium could promote the germination and growth of cherry radish in salt-free hydroponic, but under salt stress, although it could promote the germination of cherry radish, it is not conducive to the survival of the seedlings.

Key words: cherry radish, salt stress, fulvic acid potassium, seedling, germination rate