关键词: 锶, 菠菜, 小白菜, 核素, 富集率

Abstract: OBJECTIVE: We studied spinach and Chinese cabbage on the uptake and accumulation of strontium,explore the transfer process and characteristics of strontium from soil to plant,looking for migration of strontium in soil-plant system. METHODS: We chose stable nuclide ⁸⁸Sr instead of ⁹⁰Sr and used potted plants of spinach and Chinese cabbage in greenhouse. There were 5 experimental groups and a control group,each of which had three parallel samples. Strontium in the experimental groups contained in the potting soil concentrations of 1.5 times,2.0 times,2.5 times,3.0 times,3.5 times,equivalent to strontium in soil of 318.67,478.00,637.33,796.67,956.00 mg/kg,respectively. The soil of the control group was natural air drying in shade,being mashed before being sifted by the 30 specifications sieve and was used directly. During the experiment,we irrigated the plants with deionized water. When the plants grow 30 days after seeding,we collected the stem and leaf on the ground and roots underground. After drying,crushing and digestion,it was set suspended in 10 mL solvent. All the strontium concentrations in the plants and the soil were measured wie inductively coupled plasma atomic emission spectrometry(ICP-AES) in this experiment,and the strontium concentration ratio(CR) of the two vegetables was calculated. The accumulation characteristics of strontium in soil-plant system was studied. RESULTS: The strontium content in plant rose with increasing concentration in soil. The CR values of two vegetables,except for the low concentration group(318.67 mg/kg),showed significant differences(P<0.05) compared wie control group. The CR values of the high concentration group of spinach(697.67 and 956.00 mg/kg) were significantly higher than that of strontium in Chinese cabbage(P<0.05). Strontium and calcium contents of Chinese cabbage stems and leaves,and spinach root strontium and iron contents showed a negative correlation,and the rest had positive correlations. The concentration rate of strontium of the two kinds of vegetables,except for the spinach low concentration group(318.67 mg/kg) and Chinese cabbage low concentration groups(318.67 and 478.00 mg/kg),other groups were significantly increased compared wie control group(P<0.05). Between the two kinds of vegetables,strontium concentration rate of high concentration group of spinach(796.67 and 956.00 mg/kg) was significantly higher than Chinese cabbage(P<0.05). CONCLUSION: Spinach and Chinese cabbage showed great uptake and accumulation of stable strontium. The CR values of strontium in the high concentration group of spinach were significantly higher than that of Chinese cabbage.

Key words: strontium, spinach and Chinese cabbage, nuclide, concentration ratio