拔节期低温对小麦籽粒产量与灌浆期旗叶荧光参数的影响

Effects of low temperature at jointing stage on grain yield and fluorescence parameters of flag leaves in wheat grain filling

为探明拔节期低温对小麦生育后期旗叶荧光特性的影响,以华成3366、扬麦13等7个小麦品种为材料,在拔节期对小麦进行低温处理,研究低温对小麦籽粒灌浆期旗叶荧光参数的影响。结果表明,拔节期低温显著降低小麦籽粒产量,低温处理下小麦籽粒产量较对照降低44.53%—65.74%,其中小麦品种生选6号降幅较小、宁麦13降幅较大。拔节期低温对小麦灌浆期旗叶荧光参数具有显著影响。与对照相比,低温处理下小麦旗叶实际光化学效率(ΦPSⅡ)、最大光化学量子产量(Fv/Fm)、光化学淬灭系数(qP)和表观电子传递速率(ETR)显著下降,PSⅡ非调节性能量耗散的量子产额Y(NO)和初始荧光(F0)显著升高,最大荧光(Fm)、非光化学淬灭系数(qN)和PSⅡ调节性能量耗散的量子产额Y(NPQ)无显著变化。品种间,生选6号的Fv/Fm、ETR和ΦPSⅡ等荧光参数低温处理下降幅较小,宁麦13的Fv/Fm、ETR和ΦPSⅡ等荧光参数低温处理下降幅较大。从相关性分析结果得出,F0与Fv/Fm呈负相关,qP与ETR呈正相关,Y(NO)与ΦPSⅡ呈负相关。表明拔节期低温主要通过增加光损伤、增加热和荧光的光能消耗,从而降低电子传递速率,进而降低叶片光系统Ⅱ的最大光化学量子产量、实际光化学效率。并得出旗叶荧光参数受低温影响较小的小麦品种减产较少。

This paper aims at probing the effects of low temperature stress at jointing stage on its fluorescense characteristics of flag leaves at late growth stage in wheat. Seven wheat varieties, such as Huacheng 3366, Yangmai 13 and so on, were used as materials, and were treated under low temperature at jointing stage. The effects of low temperature on the fluorescence parameters of flag leaves during grain filling were studied. The results showed that low temperature at jointing stage significantly reduced grain yield of wheat. The grain yield of wheat was 44.53%-65.74% lower in low temperature treatment at booting than in the control. Among them, the decrease of Shengxuan 6 was smaller, and that of Ningmai 13 was larger.Low temperature at jointing stage had a significant effect on the fluorescence parameters of flag leaves at wheat filling stage.Compared to the control, actual photochemical efficiency( Φ PS Ⅱ), maximum photochemical efficiency(Fv/Fm),photochemical quenching(qP) and apparent photosynthetic electron transfer rate(ETR) decreased significantly, quantum yield of non-regulated energy dissipation Y(NO) and minimal fluorescence(F0) increased significantly and maximal fluorescence(Fm), non-photochemical quenching(qN) and the parameters of quantum yield of regulated energy dissipation Y(NPQ) had no significant change under low temperature treatment. Comparison between varieties, the decrease Fv/Fm, ETR and ΦPSⅡ of Shengxuan6 was small under low temperature, the drop Fv/Fm, ETR and ΦPSⅡ of Ningmai13 was large under low temperature. According to correlation analysis, F0 was significantly negatively correlated to Fv/Fm. qP was significantly positively correlated to ETR. Y(NO) was significantly negatively correlated to ΦPSⅡ. The decreases in electron transfer rate under low temperature condition were mainly attributed to the increased light damage and increased heat and fluorescent light energy consumption, leading to the reduction of maximum photochemical efficiency and actual photochemical efficiency. And it was concluded that the wheat varieties with less fluorescence parameters affected by low temperature had effect of small for yield.