Fig.5
It can be seen from Figure 5 that the total polyphenol content ofDendrobium nobile varies with the zinc treatment concentration. When the zinc concentration is less than 400μmol/L, the polyphenol content gradually increases with the increase of zinc concentration. When the zinc concentration is 400 μmol/L, compared with the control, it is significantly higher than the control. When the zinc treatment time is 14 days, the content of polyphenols reaches the maximum. When the concentration of zinc was more than 400 μmol/L, the content of polyphenols decreased with the increase of zinc concentration, but it was still significantly higher than the control group.
It can be seen from Figure 5 that the flavonoid content ofDendrobium nobile varies with the zinc treatment concentration. When the zinc concentration is less than 400μmol/L, the flavonoid content gradually increases with the increase of zinc concentration. When the zinc concentration was 400 μmol/L, it was significantly higher than the control, and when the zinc treatment time was 21 days, the content of flavonoids reached the maximum. When the zinc concentration is more than 400 μmol/L, the content of polysaccharide decreases with the increase of zinc concentration. When the zinc treatment time was less than 21 days, it was still significantly higher than the control group. However, when the zinc treatment time was more than 21 days, the content of flavonoids decreased.