限水灌溉对冬小麦旗叶某些光合特性的影响

Effects of Limited Irrigation on Some Photosynthetic Functions of Flag Leaves i n Winter Wheat

用叶绿素荧光诱导动力学技术 ,研究冬小麦旗叶光合功能对春灌的响应状况。结果表明 :与不春灌相比 ,2次春灌有利于 76选系、特别是 4 0 4 1提高旗叶的 PS 活性 ,PS 光化学的最大效率 ,q P值 ,表观光合电子传递速率和 PS 总的光化学量子产量 ,而降低 q N值 ;但这种改善光合功能的作用只有在灌浆后期才比较明显。就抗旱品种山农 4 5而言 ,春灌并不改善旗叶的光合功能。由此推测 ,适当减少冬小麦春灌次数 。

Modulated chlorophyll fluorescence induction kinetics was used to in vestigate the effect of the spring irrigation on the photosynthetic functions of flag leaves of different winter wheat cultivars. The results showed that the ph otosynthetic functions of flag leaves of different winter wheat cultivars variou sly responded to spring irrigation and non irrigation. PSⅡ activity, the maxim a l efficiency of PSⅡ photochemistry, the photochemical quenching coefficient (qP ), the apparent photosynthetic electron transport rate (ETR) and overall photoch emical quantum yield of PSⅡ (Yield) of the flag leaves in 76 Xuanxi, especially 4041 were raised and non photochemical quenching coefficient (qN) was decrease d by irrigation at jointing stage and grain filling stage. However, the significa nt differences of the above mentioned photosynthetic functions between the trea t ments of spring irrigation and non irrigation of 76 Xuanxi appeared in the rath e r late period. At the same time, photosynthetic functions of flag leaves in Shan nong 45 were not improved by spring irrigation. Therefore, it was feasible for w inter wheat, especially for drought resistance cultivars to reduce the irrigatio n frequency in spring.