硝普钠、24-表油菜素内酯\水杨酸浸种对盐胁迫下玉米种子萌发及幼苗生长的影响

采用营养液水培,以玉米品种天泰16(TT16)、豫玉18(YY18)为材料,探讨外源硝普钠(NO的外源供体SNP)+2,4-表油菜素内酯(EBR)/水杨酸(SA)浸种对盐胁迫下玉米种子萌发及幼苗生长的影响。结果显示,2种外源物组合浸种后,促进了盐胁迫(150mmol/L NaCl溶液)下玉米种子的萌发,以500mg/L 24-表油菜素内酯+硝普钠复合浸种和200mg/L水杨酸+硝普钠复合浸种效果最佳,其发芽率TT16分别比对照增加15%和13%,YY18增加16%和13%;发芽势TT16分别比对照增加24%和22%,YY18增加43%和44%,主根长、芽长及生物量也较对照增加。经外源物质浸种后,盐胁迫下的玉米幼苗长势较好,SOD、POD酶活性相比对照增加显著,MDA含量较少,可溶性糖在200mg/L水杨酸+硝普钠浸种的幼苗中积累最多,分别为对照的4.35倍(TT16)和4.03倍(YY18)。与对照相比,500mg/L EBR+100mmol/L SNP复合浸种和200mg/L SA+100mmol/L SNP复合浸种,玉米种子及幼苗耐盐性增强。

EFFECTS OF PRIMING WITH SODIUM NITROPRUSSIDE AND 24-EPIBRASSINOLIDE OR SALYLIC ACID ON SEED GERMINATION AND GROWTH OF MAIZE UNDER SALT STRESS

The aim of this study was to study effects of exogenous sodium nitroprusside (SNP)+2,4-epibrassinolide(EBR) or salylic acid (SA) on the germination of seeds, activities of antioxidative enzymes,MDA and soluble sugar in the leaves of maize (Zea mays L. cv. Tiantai No.16 and Yuyu No.18) seedlings under salt stress. After the seeds were soaked in one or two exogenous substances, especially in SNP +500mg/L EBR or SNP+200mg/L SA solution, their germination vigots were improved by 24%/22% (TT16) and 43%/40% (YY18) respectively, and germination percentage were increased by 15%/13%(TT16) and 16%/13%(YY18), respectively with higher activities of antioxidative enzymes and 109%/435%(TT16) and 119%/403%(YY18) higher soluble sugar in leaves under salt stress, while the accumulation of malondialdehyde (MDA) decreased by 70% /66%(TT16) and 66%/68%(YY18) as compared to control. It was suggested that SNP +EBR or SNP+SA could promote the seed germination and seedlings growth of maize exposed to salt stress through increasing seedlings' scanvenging ability of reactive oxgen species and accumulating soluble sugar.