摘要
测定了大田种植条件下４ 个不同籽粒蛋白质含量小麦品系旗叶的净光合作用、光呼吸作用和荧光参数的日变化以及旗叶功能期内ＰＳⅡ光化学效率的变化。结果表明：高、低蛋白小麦旗叶的净光合速率无显著差异，但中午强光胁迫下高蛋白小麦ＰＳⅡ光化学效率（Ｆｖ／Ｆｍ） 较高，ＰＳⅡＦｖ／Ｆｍ 下降得较少，而净光合速率午间下降的幅度较大，原因可能是高蛋白小麦品系旗叶内氮素代谢活动旺盛（ 其代谢限速酶硝酸还原酶活性显著高于低蛋白品种） ，光呼吸作用较强，从而消耗了较多的过剩激发能，在一定程度上减轻了Ｆｖ／Ｆｍ 的下降。
Diurnal changes of net photosynthetic rates (Pn, Fig.1), photorespiration (Fig.2) and fluorescence parameters (Fig.3), as well as changes in photochemical efficiency of PSⅡ (Fig.4) after flag leaves expanded of four wheat cultivars with different protein content, were determined under the field conditions. Results showed, under strong irradiance around noon, there was little difference in Pn between high and low protein wheat cultivars (Fig.1), but photorespiration (Fig.2) and Fv/Fm of PSⅡ (Figs.3,4) of high protein wheat cultivars were higher, the value of Fv/Fm declined slightly, Pn declined faster after noon, as compared with low protein wheat cultivars. Those are mostly due to the facts that the active nitrogen metabolism (Table 1) and photorespiration (Fig.2) in flag leaves of high protein wheat cultivars dissipated much excessive excited energy under high irradiance around noon and higher photorespiration depressed photosynthesis.
基金
国家自然科学基金
山东省自然科学基金
关键词
高蛋白小麦
PSⅡ
光化学效率
光呼吸
氮素代谢
high protein wheat cultivars ( Triticum aestivum L.), photochemical efficiency of photosystem Ⅱ (Fv/Fm), photorespiration, nitrogen metabolism
