外源褪黑素对盐胁迫下黄心菜种子萌发及幼苗生长的影响

Effects of Exogenous Melatonin on Seed Germination and Seedling Growth of Brassica pekinensis(Lour.)Rupr.under Salt Stress

为探明不同浓度褪黑素对盐胁迫下黄心菜种子萌发及幼苗生长发育的影响,本试验以黄心菜品种‘黄心乌’为试材,研究0.1 mol·L^(-1)NaCl胁迫下不同浓度(0、10、20、40、80、160μmol·L^(-1))褪黑素浸种对黄心菜种子萌发的影响和0.15 mol·L^(-1)NaCl胁迫下叶面喷施不同浓度(0、25、50、100、200、400μmol·L^(-1))褪黑素对黄心菜幼苗生长的影响。结果表明,10μmol·L^(-1)褪黑素浸种对盐胁迫下黄心菜种子发芽率、下胚轴长、胚根长及幼芽鲜重具有显著促进作用;盐胁迫下叶面喷施100μmol·L^(-1)褪黑素处理幼苗叶长、叶宽、株幅和超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、脯氨酸含量、可溶性蛋白含量显著高于其他处理。综合看出,0.1 mol·L^(-1)NaCl胁迫处理时,10μmol·L^(-1)褪黑素浸种可显著缓解盐胁迫对种子萌发时抑制作用,0.15 mol·L^(-1)NaCl胁迫处理时,叶面喷施100μmol·L^(-1)褪黑素可显著缓解盐胁迫对幼苗生长的抑制作用。

To investigate the effects of different concentrations of melatonin on seed germination and seedling growth and development of Brassica pekinensis under salt stress,this experiment was conducted with the variety‘Huangxinwu'as test material,and the effects of different concentrations(0,10,20,40,80 and 160μmol·L^(-1))of melatonin soaking on seed germination of B.pekinensis were studied under 0.1 mol·L^(-1)NaCl stress,and also the effects of foliar spraying different concentrations(0,25,50,100,200 and 400μmol·L^(-1))of melatonin on seedling growth under 0.15 mol·L^(-1)NaCl stress.The results showed that soaking seeds with 10μmol·L^(-1)melatonin had the significant promoting effects on germination rate,hypocotyl length,embryonic root length and bud fresh weight of B.pekinensis under salt stress.Under salt stress,foliar spraying 100μmol·L^(-1)melatonin significantly increased the leaf length,leaf width,plant width,superoxide dismutase(SOD)activity,peroxidase(POD)activity,proline content and soluble protein content of seedlings compared to the other treatments.Overall,under 0.1 mol·L^(-1)NaCl stress,soaking seeds with 10μmol·L^(-1)melatonin could significantly alleviate the inhibition effect of salt stress on seed germination;under 0.15 mol·L^(-1)NaCl stress,foliar spraying 100μmol·L^(-1)melatonin could significantly alleviate the inhibitory effect of salt stress on seedling growth.