外源褪黑素对猕猴桃实生苗耐涝性的影响

Effects of Exogenous Melatonin on Waterlogging Tolerance in Kiwifruit Seedlings

【目的】探讨外施不同浓度褪黑素溶液(MT)对淹水胁迫下两个猕猴桃品种‘布鲁诺’和‘红实2号’生理特性的影响,为在栽培中应用MT提高猕猴桃的耐涝性提供依据。【方法】对当年生实生苗进行0、50、100和200μmol/L外源MT根灌预处理后,进行淹水胁迫处理,测定相关生理指标,结合隶属函数法综合评价出最适外源MT预处理浓度。【结果】施用褪黑素后,两个品种的幼苗在淹水处理下叶片和根系的损伤程度明显减弱,植株的生长参数、光合色素含量和气体交换参数均较淹水对照显著提高,而相对电导率、丙二醛含量较对照降低,说明MT预处理不同程度上减缓了淹水胁迫对猕猴桃幼苗造成的伤害,提高了耐涝性。通过隶属函数综合评价得出两个品种最适外源MT预处理浓度均为100μmol/L。【结论】不同浓度外源MT预处理减轻了淹水胁迫对猕猴桃幼苗造成的损害,以100μmol/L MT预处理浓度效果最好。

【Objective】The effect of application of different concentrations of melatonin(MT)solution on the physiological characteristics of two kiwifruit varieties ’Bruno’ and ’Hongshi 2’ under flooding stress were investigated,it provides a basis for improving the waterlogging tolerance of kiwifruit by using MT in cultivation.【Method】The seedlings were pretreated with 0、50、100 and 200 μmol/L MT solution,and then subjected to waterlogging treatment. The relevant physiological indexes were measured,and the optimal concentration of exogenous MT was evaluated comprehensively by subject-function method.【Result】Application of melatonin significantly mitigated the damage degree of seedling leaves and roots in both cultivars caused by waterlogging,and the growth parameters,photosynthetic pigment content and gas exchange parameters were significantly increased compared with the waterlogging control,while the relative electrical conductivity and malondialdehyde content were decreased compared with the control.These results indicated that MT pretreatment alleviated the damage caused by waterlogging stress on kiwifruit seedlings to some extent and improved waterlogging resistance. through comprehensive evaluation of the membership function,the optimal of MT pretreatment concentration for both cultivars was 100 μmol/L. 【Conclusion】 Different concentrations of exogenous MT pretreatment alleviated the damage caused by flooding to kiwifruit seedlings,and the pretreatment concentration of 100 μmol/L MT had the best effect.