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用盆栽‘蛇龙珠’葡萄进行的试验表明,不同时期中等程度的分期干旱胁迫均诱导了果实的渗透调节。黎明时果实最高水势状况下,溶质势下降值在0.6MPa左右,压力势上升值为0.1~0.2MPa;在同样的含水量下,与对照相比,干旱胁迫后具渗透调节能力的果实具有更低的水势、更低的溶质势和更高的压力势。果实发育第Ⅰ期干旱胁迫在诱导了果实渗透调节的同时也诱导了细胞壁刚性的大幅度升高;复水后渗透调节能力和细胞壁刚性下降,生长速率仍然较低。第Ⅱ期胁迫没有显著改变此期果实压力势不高、细胞壁刚性较大的生理状况;而在第Ⅲ期复水后,细胞壁刚性下降,细胞扩张能力增大。第Ⅲ期干旱胁迫在更高的程度上维持了细胞的压力势。第Ⅰ、Ⅱ期和Ⅱ、Ⅲ期持续干旱胁迫使果实渗透调节能力下降乃至丧失,压力势下降,细胞壁刚性则大幅度升高。据以上结果讨论了葡萄果实不同生长期对干旱的敏感性变化的机制。
Experiments conducted in the potted “Cabernet Gernischt” grape showed that moderate staging drought stress induced the osmotic adjustment of fruit at different stages. Under the condition of the highest water potential at dawn, the descending value of solute potential was about 0.6MPa and the pressure potential increased by 0.1 ~ 0.2MPa. Under the same water content, compared with the control, the ability of osmotic adjustment after drought stress The fruit has lower water potential, lower solute potential and higher pressure potential. Drought stress during fruit development induced the osmotic adjustment of fruit and induced a substantial increase of cell wall stiffness. After rewatering, the ability of osmotic adjustment and cell wall rigidity decreased and the growth rate was still low. Stage II stress did not significantly change the physiological pressure of the fruit during this period is not high pressure, rigid cell wall larger physiological condition; and in the third phase of rehydration, cell wall rigidity decreased, cell expansion capacity increased. Stage III drought stress to a higher extent to maintain the pressure of cells. In the first and the second and the second and the third continuous drought stress, the osmotic adjustment ability of the fruit decreased or even decreased, the pressure potential decreased and the cell wall rigidity increased greatly. Based on the above results, we discussed the mechanism of the sensitivity to drought in different growth stages of grape fruit.