水分亏缺条件下褪黑素对春小麦光合特性及产量性状的影响

Effects of melatonin on photosynthetic characteristics and yield traits of spring wheat under water deficit

【目的】明确水分亏缺条件下褪黑素处理对春小麦籽粒产量的调控机理。【方法】以内蒙古春小麦水地主栽品种农麦2号与永良4号为试验材料,采用完全随机区组设计,在正常灌水与水分亏缺处理下,研究外源褪黑素对春小麦叶绿素含量、光合速率、单株生物量、穗数、穗粒数、千粒重、籽粒产量等主要表型性状的影响。【结果】与正常灌水处理相比,水分亏缺处理降低了春小麦功能叶片叶绿素含量和光合速率,阻碍了植株生物量的积累,降低了穗数、穗粒数和千粒重,导致减产19.01%~20.35%。水分亏缺条件下,褪黑素处理可以缓解水分亏缺对叶片造成的伤害,维持较高的叶绿素含量与光合速率,促进了植株生物量的积累,抑制了穗数、穗粒数和千粒重的降低,较增产13.19%~17.27%。【结论】褪黑素作为一种绿色生长调节剂对增强春小麦适应能力、应对水分亏缺频繁发生具有重要作用。

【Objective】To clarify the regulating effect of melatonin treatment on spring wheat yield under water deficit conditions.【Methods】In the experiment,the spring wheat irrigated varieties Nongmai2 and Yongliang4 were used as test materials.Using randomized complete block design,the effects of exogenous melatonin on the main phenotypic traits of spring wheat,such as chlorophyll content,photosynthetic rate,biomass per plant,spike number,grain number per spike,thousand kernel weight and grain yield,were studied under well-watered and water deficit treatments.【Results】Compared with well-watered treatment,water deficit treatment reduced the chlorophyll content and photosynthetic rate of functional leaves of spring wheat,hindered the accumulation of biomass per plant,reduced spike number,grain number per spike,and thousand kernel weight,reduced yield by 19.01%-20.35%.Under water deficit conditions,melatonin treatment could alleviate the damage to leaves caused by water deficit,maintain high chlorophyll content and photosynthetic rate,promote the accumulation of biomass per plant,inhibit the decrease of spike number,grain number per spike and thousand kernel weight,and increase yield by 13.19%-17.27%.【Conclusion】As a green growth regulator,melatonin played an important role in enhancing the adaptability of spring wheat and coping with frequent water deficit.