γ 氨基丁酸对冬小麦籽粒灌浆期耐热性及产量和品质的影响

为探讨γ-氨基丁醇(GABA)在小麦抗高温胁迫中应用的可行性,以冬小麦品种中优9507为试验材料, 在开花期喷施200 mg/L GABA, 灌浆期通过塑料棚覆盖模拟高温(45℃)处理,研究外源GABA对冬小麦灌浆期耐热性的影响.结果表明, 在高温胁迫条件下,200 mg/L GABA处理使中优9507小麦较清水对照产量增加了11.0%, 千粒重增加了4.6%; 粗蛋白增加了4.3个百分点, 并显著提高了沉淀值和干、湿面筋含量; 高温条件下GABA处理使得旗叶中MDA含量降低了49.2%, SOD活性提高了14.0%, 可溶性糖含量也显著升高; 旗叶的IAA含量显著下降, ABA含量明显升高.上述结果表明, GABA可通过调节内源激素系统、保护膜稳定性、增加抗氧化酶活性和活性氧清除能力、调节C/N代谢平衡来增强冬小麦耐高温的能力, 并在一定程度上减少高温胁迫带来的产量损失.

Effects of Exogenous GABA on Yield, Quality, and High Temperature Tolerance during Anthesis Stage of Winter Wheat

Winter wheat (Triticum aestivum L.) Zhongyou9507 was chose to study the effect of exogenous gamma aminobutyric acid (γGABA) on high temperature tolerance of winter wheat during grain filling period. 200 mg/L GABA was sprayed during anthesis, and simulated high temperature (45℃) environment was achieved through plastic film covered shed. Results showed that yield, thousand kernels weight and gross protein content of Zhongyou 9507 increased by 11.0%, 4.6% and 4.3 percentage points, respectively. At the same time， the content of MDA decreased significantly by 49.2% and the activity of SOD increased by 14.1% in flag leaf after GABA application under high temperature stress. Furthermore, the content of IAA decreased and ABA increased in flag leaf under stress. It was primarily concluded that GABA could improve high temperature tolerance of winter wheat by regulating endogenous hormone system, protecting membrane stability, increasing the activity of antioxidant enzymes, removing active oxygen species and modulating the balance of C/N metabolism, and lessen the yield loss brought by the high temperature.