关键词: 芥蓝, 铁浓度, 水培, 生长, 品质

Abstract:

Dwarf phenomenon, chlorosis, low quality often occur in hydroponics kale because of iron deficiency, while the plant growth would be easily inhibited by high iron concentration due to the physiological obstacle brought about iron toxicity. In this study, the effects of iron concentrations (2.8 mg/L, 5.6 mg/L, 8.4 mg/L, 11.2 mg/L and 14 mg/L, with EDTA-Fe as a source) on the growth, quality and some physiological characteristics of hydroponic Chinese kale was investigated. Results showed that the plant fresh weight and plant height increased significantly as the iron concentration went up to 8.4 mg/L. But when the iron concentration went over 8.4 mg/L, the plant fresh weight did not increase and plant height even dropped down. It was conducive to improve nutrient contents of Chinese kale, to increase iron concentration within a certain range. The contents of soluble protein, soluble sugar and vitamin C in leaf and bolting stem would increase significantly along with the increase of iron concentration. But, the soluble protein content in leaf did not increase when the iron concentration was higher than 8.4 mg/L. The soluble protein content in bolting stem, and soluble sugar contents in leaf and bolting stem would not increase when the iron concentration was over 11.2 mg/L. Chlorophyll content, CAT and POD activities of leaf showed the tendency of first raising then dropping with the adding of iron concentration, and then reached the peak when iron concentration was 8.4 mg/L. The vitality of root system was in the same situation. Total plant iron content also increased at first and then decreased with the increase of iron concentration. The peak of total iron content in leaf was at the iron concentration of 8.4 mg/L, and the peak of total iron contents in bolting stem and root was at 11.2 mg/L. So 8.4 mg/L was considered the most appropriate iron concentration of the nutrient solution for hydroponic Chinese kale under this experimental condition.

Key words: Chinese kale, iron concentration, hydroponics, growth, quality