低磷胁迫对不同水稻品种幼苗光合作用的影响

Effect of Low Phosphorus Stress on Leaf Photosynthesis in the Seedlings of Different Rice (Oryza sativa L.) Cultivars

低磷胁迫下 ,水稻叶片的无机磷含量、光合速率、RuBP羧化酶活性下降。与低磷敏感品种沪占七相比 ,耐低磷品种大粒稻无机磷含量、RuBP羧化酶活性下降的幅度更小。在低磷胁迫初期 (10d)较低光强下 ,大粒稻与沪占七光合速率受低磷的影响相近 ,而较高光强下以及胁迫后期 (2 0d)大粒稻受低磷影响较小。叶绿素荧光参数测定表明 ,在低磷胁迫第 10d ,与 +P处理相比 ,大粒稻 -P处理所有参数变化不大 ,而沪占七qn 上升明显 ;在低磷胁迫的第 2 0d ,大粒稻 -P处理的qn 上升 ,而沪占七qp、qn、ФPSⅡ

Under low phosphorus stress, the inorganic phosphorus content, RuBPcase activity and photosynthetic rate in the rice leaves reduced. Compared with low-phosphorus-sensitive cultivar (Huzhanqi), the inorganic phosphorus content, RuBPcase activity in low-phosphorus-tolerant cultivar (Dalidao) decreased less. Under low light intensity, the photosynthetic rate in the rice leaves of Dalidao and Huzhanqi were affected nearly same by of low phosphorus treatment for 10 days, but under higher light intensity or after 20 days treatment, Dalidao was affected less. The determination of chlorophyll fluoresecence parameters showed, low-phosphorus treatment for 10 days had little effluence on chlorophyll fluoresecence parameters in the leaves of Dalidao, however, q n of Huzhangqi increased obviously. At 20 days low-phosphorus treatment, q n in the leaves of Dalidao increased, while q p, q n, Ф PSⅡ in the leaves of Huzhanqi decreased.