The effect of chitosan oligosaccharide applied at seed and seedling stage on the low temperature tolerance of melon seedlings is mainly through its internal physiological and biochemical indicators.
Because low temperature inhibited the growth of melon seedlings, such as plant height, stem diameter and leaf area, the external indicators of melon seedlings did not change significantly.
However, low temperature stimulation will significantly change the content of related osmotic substances and the activities of related enzymes in melon seedlings.
Effects of Chitosan Oligosaccharide Soaking on Melon Seedlings
Seed soaking with chitosan oligosaccharide can significantly improve the quality of melon seedlings, and 75ppm of chitosan oligosaccharide solution is the best.
Chitosan oligosaccharide seed soaking can promote the elongation of radicle and germ of cucumber, and also significantly promote the plant height, stem diameter and leaf area. The dry weight increment is between 13.5% and 30.2%.
According to the test, chitosan oligosaccharide can significantly improve the germination rate of seeds, enhance the vitality of seeds, ensure the uniformity of seedlings and the quality of seedlings, and lay a solid foundation for the growth of seedlings.
Effects of Chitosan Oligosaccharides on Melon Seedlings
The improvement of melon seedling photosynthetic rate, chloroplast content, osmotic substance content and resistance enzyme activity contributed to the enhancement of melon seedling quality and low temperature tolerance.
The application of chitosan oligosaccharide in the melon seedling stage can be used as an elicitor to stimulate the quality of melon seedlings and the expression of low temperature tolerance genes, and significantly improve the photosynthesis rate, chlorophyll content, osmotic substance content and enzyme activity of melon seedlings.
Experiments showed that under the low temperature stress of -2 degrees, the application of chitosan oligosaccharide can significantly increase the proline content, CAT activity and SOD activity in plants, and at the same time significantly reduce the MDA content. Total antioxidant capacity was significantly improved.
Conclusion
Chitosan oligosaccharide can significantly improve the low temperature tolerance of melon seedlings. The optimal concentration of seed soaking is 75ppm, the concentration of leaf spray is 50ppm, and the concentration of root irrigation is 100ppm.