两种穗型冬小麦品种旗叶光合特性及氮素调控效应

Photosynthetic Characteristics of Flag Leaves and Nitrogen Effects in Two Winter Wheat Cultivars with Different Spike Type

在大田条件下 ,对两种穗型冬小麦品种生育后期旗叶光合特性及其氮素调控效应进行了研究。结果表明 :大穗型品种豫麦 6 6的旗叶叶绿素含量、PSⅡ潜在活性、PSⅡ光化学的最大效率、荧光光化学猝灭系数以及荧光非光化学猝灭系数等性状均优于多穗型品种豫麦 4 9,且PSⅡ量子效率和光合速率在灌浆中后期具有明显优势 ,从而有利于豫麦 6 6高穗粒重 (2 .0 85g)的形成。氮素水平对荧光动力学参数的调控存在一定差异 ,低氮水平条件下荧光光化学猝灭系数和PSⅡ量子效率最大 ;高氮条件有利于进一步改善旗叶的光合色素性状 ,增加PSⅡ潜在活性及PSⅡ光化学的最大效率 ,而减少荧光非光化学猝灭系数 ,从而有助于提高光合速率。

Field experiment was conducted to compare the photosynthetic characteristics of flag leaf in two wheat cultivars with different spike types and to investigate the effects of nitrogen levels on their photosynthetic characteristics in the late developmental stage.The results indicated that photosynthetic pigment content,PSⅡ potential activation,the maximal quantum efficiency of PSⅡ,fluorescence photochemical quenching coefficient and non-photochemical quenching coefficient of flag leaf in Yumai 66 (a large-spike cultivar) were better than in Yumai 49 (a multiple-spike cultivar). It was suggested that quantum efficiency of PSⅡ and photosynthetic rate of Yumai 66 were higher than those of Yumai 49 in the middle to late filling stage. Therefore, the grain weight per spike of Yumai 66 was higher. Fluorescence photochemical quenching coefficient and quantum efficiency of PSⅡ at low nitrogen level(B_2) was the highest.But photosynthetic pigment content,PSⅡ potential activation and the maximal quantum efficiency of PSⅡ were increased and non-photochemical quenching co-efficient was decreased by high nitrogen level(B_4),which stimulated photosynthesis increasing.