干旱和复水对两种葡萄砧木叶片光合和叶绿素荧光特性的影响

Effect of drought and rewatering on the photosynthesis and chlorophyll fluorescence of two grape rootstock leaves

采用盆栽称重控水法,干旱胁迫处理1103P和101-14M两种砧木,处理21 d后复水,分别测定干旱处理0、7、14、21 d及复水第7、14天,葡萄砧木叶片光合和叶绿素荧光参数。结果显示:干旱胁迫后,1103P和101-14M的净光合速率(Pn)均逐渐降低,101-14M的Pn降幅大于1103P,短时间干旱胁迫引起两种砧木Pn降低的主要因素是气孔限制,而长时间干旱胁迫后Pn降低主要是非气孔限制。随着干旱胁迫的持续,1103P和101-14M的初始荧光产量(Fo)呈增加趋势,但101-14M的增幅大于1103P,说明干旱胁迫后101-14M的光反应中心受损害程度大于1103P;复水后1103P和101-14M两种砧木的Pn值逐渐增加,复水第7天,二者分别为对照的83.20%和66.31%,复水第14天,分别为对照的107.30%和88.43%;复水后1103P和101-14M两种砧木的Fo值呈现逐渐降低趋势,复水后第7天,1103P和101-14M的Fo值为对照的102.95%和109.60%,复水后第14天,1103P和101-14M Fo为对照的101.56%和101.81%,说明复水后1103P和101-14M两种砧木受损的光合反应中心得到了修复,光合速率也逐渐恢复,1103P复水后恢复生长的能力高于101-14M。

In order to better understand the photosynthetic adaptability of two grape rootstocks, 1103P and 101-14M, to drought stress, the effect of continuous drought stress and rewatering on the characteristics of photosynthesis and chlorophyll fluorescence were studied. The 1103P and 101-14M were growing in pots with 40%~45% of soil relative water content (RWC) and at day 21, they were rewatered to raise the soil RWC between 70%~75%. The plants growing in the soil with 70%~75% RWC throughout the growing season were used as control. The parameters of photosynthesis and chlorophyll fluorescence were measured on the 0th, 7th, 14th, and 21st day after drought treatment and on the 7th and 14th day after rewatering. Results showed that continuous drought stress influenced the the net photosynthetic rate ( Pn ) of 101-14M and 1103P successively decreased in varying degrees, and the decrease of Pn of 101-14M was greater than 1103P. Stomatal limitation play dominant role in decline of photosynthesis in short-term drought stress, non-stomatal limitation was the main reason in decline of photosynthesis while long-term drought stress. As the drought stress continued, the minimal fluorescence ( F o ) of 1103P and 101-14M increased, while the increase of 101-14m was greater than 1103P, which indicated that the degree of damage to the photosynthesis organ of 101-14M was higher than 1103P after drought stress. The Pn of 1103P and 101-14M leaves increased gradually after rewatering. At the day 7 after rewatering, 1103P and 101-14M Pn gradually increased to 83.20% and 66.31% of the control. At the 14 th day after rewatering, Pn values of 1103P and 101-14M were at 107.30% and 88.43% compared to that of the control. The F o of 1103P and 101-14M leaves decreased gradually after rewatering. At the 7 th day after rewatering, the F o of 1103P and 101-14M decreased to 102.95% and 109.60% over the control, and the 14 th day after rewatering, the F o of 1103P and 101-14M decreased to 101.56% and 101.81% compared to the control. These results indicated that the damage to the photosynthesis organs could be repaired and reach the same level of F o of the control after rewatering, and photosynthesis of 1103P leaf had the stronger ability to recover from drought stress than that of 101-14M once the stress was terminated.