叶位对冬小麦光合生理特性及冠层微气象因子日变化的影响

Effect of Leaf Position on Photosynthetic and Physiological Properties and Diurnal Variation of Canopy Micrometeorologic Factors in Winter Wheat

[目的]揭示自然条件下冬小麦不同叶位叶片的光合生理特性日变化规律。[方法]以潍麦8号(W8)和济南20(J20)为试材,在自然条件下,对5个种植密度(90、180、270、360、450株/m2)冬小麦冠层中的PARi、Ta、RH、Ca等微气象因子的日变化进行了测定。[结果]叶位对PARi值的影响达到了显著水平,不同叶位的PARi值表现为上部叶>中部叶>下部叶,随着密度增大,该显著性逐渐增大,而对其他微气象因子如Ta、RH、Ca等值的影响则不明显。不同密度处理下叶位对Pn值的影响是上部叶>中部叶>下部叶,且随着密度增大,叶位对Pn值的影响越显著,但是密度处理对上部叶位Pn值的影响没有达到显著水平(P<0.05);另外,叶位对Tr、Ci、Gs等生理因子的影响亦达到显著水平。[结论]该研究为冬小麦光合生产力模拟提供依据。

[Objective] The study aimed to disclosure diurnal variation rule of photosynthetic and physiological characteristics in leaves of different leaf positions in winter wheat. [Method] With W8 and J20 as tested materials, the diurnal variations of micro-meteorological factors such as PARi, Ta, RH, Ca of winter wheat canopy of 5 planting densities （90, 180, 270, 360 and 450 plants/m^2） were measured under natural conditions. [Result] Effect of leaf position on PARi value was at significant level. The PARi value of different position leaves represented as follows： upper leaves〉middle leaves〉lower leaves. The significance increased along with the increasing of density. Effect of leaf position on other micrometeorological factors such as To, RH, Ca was not significant. In all density treatments, the effect of leaf position on Pn value was as follows： upper leaves〉middle leaves〉lower leaves and this effect were more significant along with the increase of planting density. But the effect of density on Pn value of upper leaves was not significant （P〈0.05）. Otherwise, the effect of leaf position on other physiological factors such as Tr, Ci and Gs also reached significant level. [Conclusion] This research provided basis for simulating photosynthetic productivity of winter wheat.