Study on Control Mechanism of Growth and Development of Fruit Trees with Chitosan Oligosaccharides Soil Conditioner

壳寡糖土壤改良剂促进了无花果果实的形成和西番莲的花芽萌发。施氮量越高，这一效应越强。连续使用土壤改良剂可促进西番莲在较少氮素条件下的成花。这些结果表明，土壤条件通过提高氮素利用率和提高产量来促进果树的花分化。土壤改良剂对葡萄开花没有影响，说明土壤改良剂对不同果树品种开花的影响不同，在西番莲和番木瓜上，土壤改良剂促进了根和茎的生长、叶绿素含量和光合速率的提高。此外，在土壤改良剂处理的植株中，细胞分裂素样活性被促进。土壤调理剂参与细胞分裂素的活性对果树的生长发育起着重要作用。纸层析结果表明，土壤调理剂中含有促进或抑制植物生长的两种物质。这些物质影响了地上部的生长、果实的生长和果实中糖的积累。这说明土壤改良剂对果树生长或果实生长的影响涉及两种物质。进一步研究土壤改良剂的结构和生物活性特征，将有助于更有效地利用土壤改良剂进行果品生产。

Chitosan oligosaccharides soil conditioner increased the fruit formation in fig and flower nitiation in passionfruit. This effect was more enhanced with high level of nitrogen application. Succesive use of the soil conditioner increased flower formation under less nitrogen condition in passionfruit. These results indicates that the soil conditionerpromote the flower differentiation of fruit trees through increasing the nitrogen use efficiency and increase the yield. However, the soil conditioner did not affect the flower initiation of grape, suggesting that the effect of soil conditioner is diffrent among fruit tree species.In passionfruit and papaya, soil conditioner increased the root and stem growth, chlorophyll content and photosynthetic rate. Furthermore, cytokinin-like activities were promoted in the plants treated with soil conditiner. The involvement of soil conditioner in cytokinin activity plays an important role for growth and development of fruit trees.Two subsutances which promote orinhibit plant growth were found in the soil conditioner with paper chormatograph. These substances affected the shoot growth, fruit growth and sugar accumulation into fruit. This indicates that tow substances are involved in the effect of soil conditioner on the fruit tree growth or fruit growth. Further study to carify the structures and the features of biological activity will be helpful to utilize the soil conditioner more effeciently for fruit production.