Effects of Sulfonamide-Sulfamethazine on Growth and Physiological Indexes of Brassica campestris and Its Correlation Analysis

The effects of single and compound pollution of sulfonamides (SA) and sulfamethazine (SMT) on the growth and physiology of Brassica campestris were studied by seed germination and hydroponic experiments. The correlations between Brassica campestris growth & physiological indexes with SA, SMT were analyzed. The results showed that the effect of low concentration of SAs on the germination of Brassica campestris seeds was not significant. Under single and combined pollution conditions, compared with the control group, the growth and quality of Brassica campestris were affected. The inhibitory effects on root elongation, shoot elongation, fresh weight and dry weight of Brassica campestris increased with the increase of SAs concentration, the content of chlorophyll and soluble protein in Brassica campestris showed a general downward trend. Under single pollution, the content of malondialdehyde (MDA) increased with the increase of SA concentration. With the increase of SMT concentration, the content of MDA increased at first and then decreased, while the MDA content decreased with compound pollution. The content of SAs in Brassica campestris increased with the increase of SAs pollution concentration, and the enrichment of SMT was greater than that of SA. Pearson correlation analysis showed that SAs had a good correlation with soluble protein, chlorophyll, CAT activity and POD activity of Brassica campestris under single and combined pollution conditions, respectively. Under the SAs pollution, the physiological growth indexes and quality of Brassica campestris were affected by different degrees. The SAs content in Brassica campestris increased with the increase of SAs pollution concentration, and the enrichment of SMT was greater than that of SA. SAs can be enriched into Brassica campestris leading to potential food safety risks.