孕穗期干旱及复水对水稻叶片生理生化和产量的影响

Effects of Drought and Re-watering on Rice Physiological and Biochemical Indexes of Leaves and Grain Yield at Booting Stage

现有关于水稻干旱胁迫期间各项生理生化指标的变化和对叶片细胞的伤害机理方面的研究已经比较丰富和全面,但是对于干旱胁迫结束复水后的生理变化研究却较少。本文以水稻品种中旱3号和黄华占为材料,在孕穗期进行淹水、轻度干旱、中度干旱和重度干旱4个处理,研究了干旱胁迫对水稻叶片生理生化性状（光合作用和抗氧化酶活性等）和产量的影响。结果表明,中度和重度干旱使水稻叶片光合速率下降12.9%~43.9%,这主要与气孔导度变化有关;处理结束复水后,中旱3号的生理生化指标均能恢复到正常水平,而黄华占在重度干旱后,其光合速率、气孔导度以及抗氧化酶活性不能再恢复;干旱处理导致水稻产量降低14.3%~47.9%,主要是由于有效穗数和结实率的降低。

Although the study on drought damage mechanism of leaf cells and physiological and biochemical indexes of rice is rich and comprehensive, the study on the subsequent physiological changes after re-watering is still less. In this study, two rice varieties with different drought resistance ability, Zhonghan3 （resistant） and Huanghuazhan （non-resistant）, were used. Four treatments including flooding （CK）, low drought stress （LD）, moderate drought stress （MD） and high drought stress （HD） were implemented at booting stage. The effects of drought stress on rice leaf physiological and biochemical traits（photosynthesis, GS, SPAD, antioxidant enzyme activity, and MDA） and grain yield were studied. The main results are as follows ： 1 ） In MD and HD treatments, Pn of rice leaves decreased by 12.9%-43.9% which mainly related to Gs, while LD treatment have no significant difference in physiological and biochem- ical traits of leaf compared to CK. 2） After re-watering, all indices of leaf physiology and biochemistry for Zhonghan 3 could return to normal status under all treatments, whereas in Huanghuazhan, the target traits under LD and MD treatments could return to normal, and the HD influence could not recover after re-watering. 3） Drought stress made grain yield reduced by 14.3%-47.9% which mainly caused by the significant reduction of effective panicles and seed setting rate.