高静水压诱变水稻突变株系的叶绿素荧光特性变化

以经75 MPa高静水压处理后筛选得到的3个水稻突变株系及其亲本粤香占为材料，测定了田间生长条件下不同生育时期水稻剑叶的叶绿素荧光动力学参数。与对照亲本相比较，3个突变株系的Fv/Fm在分蘖期和抽穗期均增加，除抽穗期突变2的ΦPSⅡ略低外，其余的ΦPSⅡ都表现为增加，说明光系统Ⅱ的功能得到改善。在抽穗期，突变株系与亲本在中午高光强下受到的抑制相比，突变株系受到的抑制较小，而且在18:00以后几乎能恢复到早上6:00的水平；在灌浆期，突变株系受到的光抑制增加，但能够快速恢复。突变1、突变2和粤压1号单株产量比对照亲本分别提高268%、279%和188%。结果显示，高静水压处理萌动的水稻种子后筛选得到的突变株系叶片的叶绿素荧光特性及田间光抑制发生了改变，产量也明显提高。高静水压诱变可能成为一种筛选高产水稻品种的新途径之一。

High Hydrostatic Pressure Induced Changes of Chlorophyll Fluorescence in Rice Mutant Lines

Three mutant lines, selected from rice cultivar Yuexiangzhan treated with high hydrostatic pressure (75 MPa), and their parent were used to study the changes of chlorophyll fluorescence at different growth stages. Results showed that the function of PSⅡ was improved in the mutant lines compared to their parent Yuexiangzhan, which was indicated by increase of F_v/F_m in mutant lines at tillering stage and heading stage, and ΦPSⅡ (PSⅡ linear electron transport) also increased except mutant 2 at heading stage. Like their parent, the mutant lines also had slight photoinhibition at noon and almost completely recovered after 18:00 at heading stage. Compared with parent, the mutant lines were inhibited obviously by high light at noon and could recover rapidly after 18:00 at filling stage. Yields of individual plant and ratio of grain to straws were also higher in the 3 mutant lines than those of parent. Results indicated that characteristics of chlorophyll fluorescence in leaves of the mutant lines and their photoinhibition in the field had changed. Yield of mutant lines also increased significantly. High hydrostatic pressure-induction should be a new way to select high yield rice cultivars in the future.