不同品种小麦种子萌发及幼苗发育对外源过氧化氢处理的响应

Response of seed germination and seedling development of different wheat varieties to the treatment of exogenous H_(2)O_(2)

改良水培条件下,采用自制设备用不同浓度梯度过氧化氢(H2O2)处理小麦种子和幼苗,通过观察种子萌发以及测定幼苗发育期形态指标(株高、鲜重),生理指标(Proline、MDA、CAT)等变化,研究不同品种小麦种子萌发及幼苗发育对外源过氧化氢处理的响应情况,并深入解析过氧化氢调控小麦种子萌发及幼苗发育的生理机制。结果表明,0.3μmol/L过氧化氢对中国春、周麦36、Fielder 3种小麦种子的萌发均表现出显著的促进作用。但3种小麦幼苗对过氧化氢响应程度不同:中国春、Fielder、周麦363种小麦幼苗分别在0.3、0.1、0.1μmol/L过氧化氢处理下长势最好,而1.2μmol/L过氧化氢处理下表现出最明显的抑制效果;生理指标变化趋势表明高浓度过氧化氢对幼苗细胞造成质膜氧化损伤,从而抑制幼苗发育。综上所述,过氧化氢处理对小麦种子萌发和幼苗发育均呈现“低浓度促进、高浓度抑制”现象,不同品种小麦对外源过氧化氢处理的敏感性不同。

In the experiment,different varieties of wheat seeds and wheat seedlings were treated with different concentration gradients of hydrogen peroxide in self-made equipment,under modified hydroponic conditions.The paper observed the germination rate of wheat seeds and measured the morphological indexes(plant height,fresh weight)and physiological indexes(Proline,MDA,CAT)of seedlings under the treatment of exogenous hydrogen peroxide to research the response of different wheat varieties to exogenous hydro⁃gen peroxide treatment and analyze the mechanism of regulating wheat seed germination and seedling development.The results showed that three wheat varieties of Chinese spring,Zhoumai 36 and Fielder,all had the highest germination rate under the treatment of 0.3μmol/L hydrogen peroxide.While the plant height and fresh weight of Chinese spring seedlings were significantly promoted by hydro⁃gen peroxide at 0.3μmol/L,but inhibited at 1.2μmol/L.Hydrogen peroxide at 0.1μmol/L showed the best promotion effect on the seedling height and fresh weight of Fielder,while the concentration of 1.2μmol/L showed an obvious inhibition effect.At the same time,the results of physiological indexes indicated that high concentration of hydrogen peroxide could cause oxidative damage to plas⁃ma membrane and inhibit seedling development.In conclusion,the experimental results showed that,hydrogen peroxide treatment promoted wheat seed germination and seedling development at low concentration but inhibited at high concentration,and different wheat varieties had different levels of sensitivity to exogenous hydrogen peroxide.