超高产杂交稻剑叶衰老过程中PSII功能的变化

Changes in PSII Function during the Senescence of Flag Leavesin Super-High Yielding Hybrid Rice (Oryza sativa L.)

摘要:

对田间自然条件下培矮64S/E32和对照汕优63的剑叶衰老过程中PSII光化学效率、光能耗散和叶黄素循环组分的动态变化进行了研究。结果表明,水稻剑叶衰老过程中PSII光化学效率(F_v/F_m)、PSII量子产量(ΦPSII)、光化学猝灭系数(qP)和光合速率(P_n)均降低,但非辐射热耗散(NPQ)、叶黄素循环库和中午时的脱环氧化状态则升高。移栽后55-75 d两品种剑叶的ΦPSII和qP变化相近,此后培矮64S/E32比汕优63下降缓慢。在生育后期的衰老过程中培矮64S/E32剑叶的PSII功能比汕优63下降慢,并具有更高的光能利用效率。

Abstract:

The changes in light energy dissipation and xanthophyll cycle components in super-high yielding rice (Oryza sativa L.) cv. Peiai 64S/E32 were compared with those in traditional hybrid Shanyou 63 during the senescence of flag leaves in the field. The results showed that the maximum photochemical efficiency of PSII (F_v/F_m), quantum efficiency of PSII (ΦPSII), photochemical quenching coefficient (qP) and photosynthetic rate all decreased with the senescence of flag leaves, but the non-photochemical quenching coefficient (NPQ), the pool size of xanthophyll cycle (Z+A+V) and deepoxidation state (DES) increased. There was no significant difference in ΦPSII and qP between super-high yielding rice Peiai 64S/E32 and traditional hybrid Shanyou 63 on the 55-75 day after transplanting, but the decreases in ΦPSII and qP in Peiai 64S/E32 were less than those in Shanyou 63 after transplanting for 75 days. This suggests that there is a better PSII function for utilization of the absorbed light energy in Peiai 645/E32 than in Shanyou 63 during the senescence of flag leaves.