花后不同时期高温胁迫对春小麦荧光特性的影响

Effects of high temperature stress in different periods after anthesis on fluorescence characteristics of spring wheat

以宁夏平原主栽春小麦品种宁春4号与宁春47号为材料，在人工可控温的气候室内，采用盆栽试验，研究花后不同时期高温胁迫处理对春小麦荧光参数的影响。结果表明，高温胁迫下，两品种旗叶荧光值F0、Fm、Fv／Fm、Fv／F0、PI值均呈下降趋势，且高温处理越早下降幅度越大，与对照相比，F0下降24．02％～24．43％，Fm下降27．09％～19．63％，Fv／Fm下降19．23％～30．80％，Fv／F0下降43．64％～40．34％，PI下降66．95％～69．39％；花后不同时期的高温处理都会降低春小麦的每穗粒重、千粒重和生物量，且高温处理时间越早，下降幅度越大，其中宁春47号的千粒重降幅为17．42％～37．55％，宁春4号千粒重的降幅为36．74％～52．18％。可见花后高温导致PsⅡ遭受破坏，使春小麦的各项荧光指标降低，进而使粒重降低，产量下降。两个品种发现，宁春4号对高温较为敏感，花后高温处理会明显地降低产量，而宁春47号对高温的耐受性较强。

In order to study the effects of high temperature stress in different periods after anthesis on spring wheat fluorescence parameters, Ningchun4 and Ningchun47 were selected as the materials, which were planted in flowerpot in artificial climatic chamber. The results showed that, under high temperature stress, the value of F0, Fm, Fv/Fm, Fv/F0, PI of flag leaf all declined, and the earlier of high temperature treatment, the greater of the decline. Compared with the CK, the F0 value decreased by 24.02%-24.43%, Fm decreased by 27.09%-19.63%, Fv/Fm decreased by 19.23%-30.80%, Fv/F0 decreased by 43.64%-40.34%, PI decreased by 66.95%-69.39%. The treatment of high temperature in different periods after anthesis could also decrease grain weight per spike, 1000-grain weight and biomass of spring wheat, and the earlier of high temperature treatment, the greater of the decline. The 1000-grain weight of Ningchun47 reduced from 17.42% to 37.55% and Ningchun4 reduced from 36.74% to 52.18%. High temperature after anthesis destroyed PS II , decreased the chlorophyll fluorescence of spring wheat, then reduced grain weight and yield. Comparision of the two varieties showed that Ningchun4 was more sensitive to high temperature, so the yield declined under high temperature treatment after anthesis, but Ningchun47 was resistant to high temperature.