静水高压处理对水稻植株生理特性的影响

 以75 MPa静水高压处理萌动的水稻种子12 h，成苗后移栽至大田，研究高压处理后植株剑叶光合特性的变化。结果显示，静水高压处理后，粤香占和粤丰占种子的发芽率分别降低了14.4% 和16.6%，成苗率分别降至对照的24.6%和21.9%，生长明显受抑制，幼苗的株高在35天左右才能追赶上对照。高压处理的粤香占剑叶在生育过程中的净光合速率（P_n）和表观量子效率（AQY）的总平均值分别比未处理的对照增加了9.2%和12.4%，而粤丰占则分别增加5.7%和17.4%。高压处理后两个品种的植株叶片不同生长时期的平均光合色素含量均高于未处理的对照，在生长后期的衰老过程中高压处理植株剑叶的色素含量和PSⅡ光化学效率F_v/F_m下降速率较各自的未处理对照缓慢。高压处理后两个水稻品种的生物量和单株产量分别比对照提高了8%~27%及7%~14%。提出高压处理可能作为一种新的选育品种的方法。

Effect of High Hydrostatic Pressure Treatment on Physiological Characteristics of Rice Plants (Oryza sativa L.)

Seeds of two rice (Oryza sativa L.) cultivars, Yuexiangzhan and Yuefengzhan, were soaked for 10 h, and then were treated by 75 MPa high hydrostatic pressure for 12 h. Germination rates decreased to 85.6% (Yuexiangzhan) and 83.4% (Yuefengzhan) relative to the untreated, and seedling rates were only 24.6% (Yuexiangzhan) and 21.9% (Yuefengzhan). Plant growth was inhibited in both treated cultivars during the early growth stage of seedling, but could exceed that of the contrast after sowing of 35 d. The seedlings of the treated and untreated were transplanted in the field after sowing of 35 d. Photosynthetic characteristics were compared between the treated and untreated during flag leaf development (55~130 d after sowing). The average values of net photosynthetic rate (P_n) and apparent quantum yield (AQY) in treated cultivars increased by 9.2% and 12.4% (Yuexiangzhan), 5.7% and 17.4% (Yuefengzhan), relative to the untreated, respectively. The total average photosynthetic pigment content was higher in both treated cultivars than their untreated during different growth stage. During leaf senescence, both F_v/F_m and pigment content decreased slowly or lately in two treated cultivars than the untreated. Consequently, the biomass and grain yield increased by 8%~27% and 7.6%~14% in both treated cultivars. Several mutated strains with different morphological and yield characteristics could be selected from treated rice plants. The results suggested that high hydrostatic pressure treatment is possible served as a new method of breeding in the future.