硒、硫互作对青花菜幼苗渗透调节物质和抗氧化酶的影响
Effect of Interaction between Selenium and Sulfur on Osmotic Regulation and Antioxidant Enzymes of Broccoli Seedlings

以青花菜‘碧秀1号’为材料，通过盆栽试验研究不同浓度S、Se配施对青花菜幼苗抗氧化酶［过氧化氢酶（CAT）、过氧化物酶（POD）、超氧化物歧化酶（SOD）］活性、可溶性糖质量分数、可溶性蛋白质量分数、脯氨酸质量浓度、丙二醛（MDA）质量摩尔浓度与相对电导率的影响。结果表明，与对照（未施硫硒肥，S0Se0）相比，含1 mmol/L S、10 μmol/L Se (S1Se10)处理显著提高青花菜CAT、POD、SOD的活性；且随处理时间延长酶活性逐渐增强，显著提高可溶性糖、可溶性蛋白质量分数和脯氨酸质量浓度，但显著降低MDA质量摩尔浓度与相对电导率。硒胁迫（20 μmol/L）下高浓度硫（5、10 mmol/L）处理抑制3种抗氧化酶活性，提高青花菜幼苗叶片中MDA质量摩尔浓度与相对电导率，降低可溶性糖、可溶性蛋白和脯氨酸质量浓度，胁迫效应明显。S1Se10处理可明显增强青花菜幼苗抗氧化能力，保护细胞膜稳定性，提高其抗逆性，可作为实际青花菜富硒生产参考。
Ten interactions of different selenium(Se) and sulfur(S)of activities of the anti-oxidative enzymes and the mass fraction s of osmosis-regulating substances in seedlings of broccoli(Brassica oleracea L.var.italiea) were evaluated to provide the basis for the cultivation of the broccoli containing selenium. The results showed that the activities of antioxidant enzymes (CAT, POD, SOD) were improved significantly with treatment of 1 mmol/L S and 10 μmol/L Se(S1Se10)compared with control group (S0Se0, without S or Se). The enzyme activities were increasingly enhanced with time going on. There sults significant increased mass fraction of the soluble sugar,the soluble protein and the proline,mean while the results significant decreased in the malondialdehyde (MDA) molality and the relative conductivity.Under the treatment of selenium stress (20 μmol/L) with the high concentration of sulfur(5,10 mmol/L),three antioxidant enzymes were inhibited, the MDA molality and the relative conductivity increased,mass fraction of the soluble sugar, the soluble protein and the proline decreased, and the stress effect was more obvious. S1Se10 treatment significantly increased the antioxidant capacity of broccoli seedlings, and it could protect the stability of cell membrane and improve the stress resistance, hence, it provided references for production of broccoli.