两个水稻叶色突变体的光合特性研究

以恢复系缙恢10号为对照，对它的两个叶色突变体ygl5和pygl1在孕穗期的光合、荧光特性和叶绿体超微结构进行了研究。结果表明，两个突变体叶绿体内基粒数量明显少于对照，叶绿素含量也大幅下降，其中ygl5表现为叶绿素总体缺乏，pygl1表现为叶绿素b严重缺乏；ygl5和pygl1的P_n、光饱和点、光补偿点、暗呼吸速率、表观量子效率和羧化效率都显著高于对照，而CO₂饱和点、CO₂补偿点和光呼吸速率则低于对照；其F_v/F_m、Φ_PSII和q_P均显著高于对照，表明突变体ygl5和pygl1具有较高的光能捕获效率和转换效率。

Characteristics of Photosynthesis in Two Leaf Color Mutants of Rice

Two leaf color mutants, ygl5 and pygl1, were identified from the progeny of Jinhui 10 treated with EMS, and Jinhui 10 was an excellent restorer line bred in the Rice Research Institute of Southwest University. This paper reported their photosynthetic parameters and ultra-structure of chloroplast. Compared with the original parent, both mutants had a decline content of chlorophylls significantly, especially in total chlorophylls for ygl5 and in chlorophyll b for the pygl1. Photosynthetic and chlorophyll fluorescence parameters were determined by L1-6400, the results showed that the net photosynthetic rate (P_n), transpiration rate (T_r) and stomatal conductance (G_s) were higher in the mutants, with higher light compensation point (LCP) and lower light saturation point (LSP) as well as lower CO_2 compensation point (CCP) and CO_2 saturation point (CSP). Compared with Jinhui 10, the mutants displayed less chloroplast grana and higher optional maximal photochemical efficiency of PS II (F_v/F_m)> actual photochemical efficiency of PSII (Φ_(PSII)), and photochemical quenching (q_P), suggesting that the mutants have higher light energy capture and conversion efficiencies as well as the electron transport efficiency.