花后高温胁迫下外施多胺对小麦干物质转运及籽粒生理特性影响

【目的】探明外施多胺与减缓小麦花后高温伤害的关系并阐明其生理机制。【方法】于2018年3—7月春小麦生长期间,选用新春6号和新春31号为试验材料,在田间增温棚中进行花后8～12 d的高温胁迫处理,比较了常温对照(CK)、高温处理(HT)、高温处理下外施精胺(HT+Spm)和高温处理下外施亚精胺(HT+Spd)4种处理下干物质的积累与转运、抗氧化酶活性及渗透调节物质的差异。【结果】HT处理2个品种穗下1节花前贮藏同化物对籽粒贡献率显著升高,花后同化物对籽粒贡献率显著降低,外源喷施Spm和Spd能显著提高花后同化物对籽粒的贡献率;HT处理导致籽粒超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性、丙二醛(MDA)和可溶性糖量升高,过氧化物酶(POD)活性和脯氨酸量降低,外源Spm和Spd使HT处理下MDA和可溶性糖量降低、SOD、POD和CAT活性和脯氨酸量升高。【结论】新春6号和新春31号结果基本一致。外源Spm缓解小麦花后高温伤害的效果优于Spd。

Effects of Applied Polyamines on Wheat Assimilates Transport and Grain Physiological Characteristics under High Temperature Stress after Anthesis

【Objective】The purpose of this paper is to find out the relationship between exogenous polyamines and alleviating effect on the injury of spring wheat after anthesis under high temperature and to clarify its physiological mechanism.【Method】During the growth of spring wheat from March to July 2018, spring wheat varieties XC 6 and XC 31 were selected to treat with high temperature. The high temperature stress treatment was carried out in the shed for 8～15 days after anthesis with comparing the differences in dry matter accumulation and transport, antioxidant enzyme activity and osmotic adjustment substance content among normal temperature control(CK), high temperature treatment(HT), external application of spermine(HT + Spm) and spermidine(HT + Spd)under high temperature.【Result】HT treatment significantly increased the contributions of storage assimilates to the grains of 1 knot under panicle of the two cultivars before anthesis, while after anthesis it was significantly decreased. Exogenous spraying Spm and Spd could significantly increase the contributions to the grains of after anthesis assimilates of the two cultivars; HT treatment increased SOD and CAT activity, MDA and soluble sugar content, decreased POD activity and proline content, and exogenous Spm and Spd decreased MDA and soluble sugar content, and increased POD, CAT and SOD activity.【Conclusion】Alleviating effect of exogenous Spm on the injury of spring wheat after anthesis under high temperature was better than that of Spd.