摘要
在充分供水、维持葡萄果实整个生长期黎明时最高水势基本稳定的情况下，果实第一次快速生长期间细胞溶质势下降、压力势上升，细胞壁弹性柔量和可塑性展延性均升高至整个发育期的最高峰；此期果实细胞失水时水势下降缓慢，而且在初始质壁分离点前，水势下降主要归因于压力势的下降，表现出渗透调节能力较小的特点。果实缓慢生长期间，细胞溶质势与压力势变化较小；而细胞壁弹性柔量比第一快速生长期大为降低，可塑性展延性降至整个发育期的最低点；此期果实失水时细胞水势、溶质势和压力势的变化特点与第一快速生长期差异不大。在果实第二快速生长期，细胞溶质势的下降和压力势的上升幅度均达到整个发育期的最大值，细胞壁弹性继续缓慢下降，而可塑性展延性上升至第二个高峰；此期果实失水时水势剧降，而细胞压力势下降相对缓慢，表现出渗透调节能力较大的特点。水分胁迫在抑制果实生长时诱导了果实渗透调节和细胞壁刚性的升高，第一快速生长期水分胁迫所诱导的细胞壁刚性升高的幅度较大。讨论了果实不同发育期细胞水势分量和细胞壁展延性与果实生长之间的关系以及不同时期果实生长对水分胁迫敏感性变化的机制。
The experiment conducted under full water supply ensuring a relative constant fruit water potential at dawn during the growing season, showed that, during the first phase of rapid growth of fruit, the solute potential of fruit cell decreased while the pressure potential increased, and both the elastic and plastic extensibilities of fruit cell wall reached their maximums of the whole growing season. Fruit water potential decrease slowly when the fruit lost water, and this decrease of water potential was mainly due to the decrease of pressure potential before incipient plasmolysis,which indicated a smaller capacity of osmoregulation of fruit during this period. During the lag phase of fruit growth,there was little change in the solute potential and pressure potential of fruit cell, but the elastic extensibility of fruit cell wall was greatly decreased in comparison with the first phase of rapid growth,and the plastic extensibility of fruit cell wall reached the minimum of the whole growing season. The characteristics of the changes in fruit cell water potential,solute potential and pressure potential when fruit lost water during this period were similar to those of the first phase of rapid growth. During the second phase of rapid growth, both the decrease of fruit cell solute potential and the increase of pressure potential were the most remarkable of the whole growing season, and the elastic extensibility of fruit cell wall continued to decrease slowly while the plastic extensibility reached the second maximum. The decrease of fruit water potential was very rapid but the decrease of pressure potential of fruit cell was relatively slow when fruit lost water at this time, which indicated a great capacity of osmoregulation of fruit during this period. It was therefore considered that the continual increase of the fruit cell pressure potential during the fruit development could be the power to the fruit growth and a close coordination of the extensibility of fruit cell wall and the fruit cell pressure potential could regulate the growth rate of fruit. The first rapid growth of fruit could be related to the continual increase of the fruit cell pressure potential and that of the elastic and plastic extensibilities of fruit cell wall. The lag phase of growth was probably caused by a relative rigid, the least plastic fruit cell wall and the smaller fruit cell pressure potential during this period. The second rapid growth of fruit was considered to be powered by the intense increase of the fruit cell pressure potential and to be ensured by a recurence of the plastic extensibility increase of fruit cell wall.Water stress inhibiting fruit growth induced the osmoregulation in fruit and an increase of the cell wall rigidity of fruit, this increase of the cell wall rigidity being the most remarkable for the first phase of rapid growth. The mechanism of the changes in the sensibility of fruit growth to water stress during the different fruit developmental phases was discussed.
出处
《中国农业大学学报》
CAS
CSCD
北大核心
1997年第5期100-108,共9页
Journal of China Agricultural University
基金
国家自然科学基金!39470504
关键词
葡萄
果实生长
水势
分量
溶质势
压力势
细胞壁展延性
grapevine
fruit growth
solute potential
pressure potential
extensibility of cell wall
