少免耕模式对冬小麦生育后期光合特性的影响

    Effects of minimum tillage and no-tillage systems on photosynthetic characteristics at late growth stages of winter wheat

    • 摘要: 小麦开花后光合性能对产量具有十分重要的作用。为了研究少免耕耕作体系对冬小麦光合作用的影响,采用了4种土壤耕作模式(常规耕作秸秆还田、旋耕秸秆还田、缺口圆盘耙耕秸秆还田、免耕秸秆覆盖)在山东龙口进行了田间试验,测定了小麦开花后旗叶的光合参数、荧光动力学参数和叶绿素含量的变化。结果表明:开花后常规耕作模式的光合速率(Pn)高于旋耕还田和耙耕还田两种少耕模式,但两种少耕模式特别是耙耕还田模式的旗叶叶片衰老晚于常规还田模式,在籽粒灌浆末期仍然保持较高的叶绿素含量、最大光化学效率(Fv/Fm)、实际光化学效率(ΦPSⅡ)、光化学猝灭系数(qP),叶片有效光合时间和光合功能持续期长,有利于籽粒的充实。研究表明旋耕还田模式和耙耕还田模式可以在该地区应用,而免耕覆盖模式则不适宜。

       

      Abstract: The photosynthesis after anthesis is important for wheat yield. In order to investigate the effects of minimum tillage and no-tillage system on photosynthesis of winter wheat, four tillage systems were adopted in Longkou city, Shandong Province, China. The four tillage systems were as follows: conventional tillage with straw turnover (CS), rotary tillage with straw turnover (RS), serrated disk harrow tillage with straw turnover (HS), no-tillage with straw cover (NC). The photosynthetic efficiency after anthesis of winter wheat flag leaf of different soil tillage treatments was investigated through measurements of photosynthetic rate and chlorophyⅡ fluorescence parameters of photosystemⅡ and chlorophyll content. Results show that after anthesis, the net photosynthetic rate (Pn) of CS is higher than that of the two types of minimum tillage of RS and HS, but the senescence of flag leaf of RS and HS are later than that of CS. At the late stage of seed-filling period, two types of minimum tillage especially CS still have a higher level of chlorophyll content, maximal photochemical efficiency of PSⅡin the darkness (Fv/Fm), actual photochemical efficiency of PSⅡ in the light (ФPSⅡ), coefficient of photochemical fluorescence quenching (qP). So the minimum tillage available of photosynthesis time and the duration of photosynthesis function are longer than CS, which is good for the seed filling. Studies show that RS and HS can be adopted in this region, while NC is not suitable.

       

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