油菜素内酯对盐碱胁迫下菊花幼苗生长及生理特性的影响OA北大核心CSTPCD

In this study,the salt-tolerant chrysanthemum cultivar'Xuanqiu Jiangyue'and the salt-sensitive cultivar'Xuanqiu Duran'were used as test materials,and NaCl and NaHCO3 were mixed with 1∶1 mass ration to prepare a compound saline-alkali solution at the concentration of 100 mmol/L.The seedlings of chrysanthemum were treated with saline-alkali stress,and the leaves were sprayed with four concentrations(0.001,0.010,0.100,1.000 mg/L)of exogenous brassinolide(BR)with the H2O as the control(CK).The effects of BR on the growth and physiological indexes of chrysanthemum seedlings under saline-alkali stress were studied.The results showed that compared with the control,the relative water contents of the leaves of'Xuanqiu Jiangyue'and'Xuanqiu Duran'increased by 8.11%and 16.95%,respectively,and the chlorophyll contents increased by 9.55%and 13.97%,respectively,when sprayed with 0.100 mg/L BR under saline-alkali stress.The relative conductivities decreased by 27.63%and 24.69%,respectively.The contents of malondialdehyde(MDA)decreased by 41.24%and 67.38%,respectively.The contents of proline(Pro)increased by 86.49%and 69.46%.The activities of catalase(CAT)increased by 16.25%and 18.14%,respectively.The activities of peroxidase(POD)increased by 46.15%and 68.38%,respectively.The activities of superoxide dismutase(SOD)increased by 12.36%and 16.32%,respectively.The activities of ascorbate peroxidase(APX)increased by 76.88%and 95.04%,respectively.In summary,exogenous spraying of 0.100 mg/L BR could better promote the growth and development of chrysanthemum seedlings under saline-alkali stress,improve the activity of antioxidant enzymes and the stability of biofilms,thereby alleviate the damage of saline-alkali stress to chrysanthemum seedlings,and the alleviation effect of salt-alkali damage of salt-sensitive variety'Xuanqiu Duran'was more obvious.