The effect of low temperature on cold resistance and sugar content of different Phyllostachys propinqua
[Objective]This study focuses on the variation of relative conductivity and saccharide content in the leaves of Phyllostachys propinqua with different freezing morphologies under low-temperature stress.The aim is to provide a systematic understanding of the cold-resistance ability of different morphologies of P.propinqua,as well as the effect of saccharides on the cold-resistance of the plants.The findings will also offer technical support for the introduction and application of P.propinqua in North China.[Method]The leaves of P.propinqua with different forms were recorded and collected in winter in urban parks of Beijing.The relative conductivity and saccharide content of the leaves were determined under different low-temperature gradient treatments.[Result](1)The relative conductivity,soluble sugar,fructose and sucrose contents of different P.propinqua leaves increased significantly with the decrease of treatment temperature,while the starch content showed a decreasing trend.(2)At the low temperature,the relative conductivity in dried leaves was significantly higher than that in other types of leaves;The soluble sugar,sucrose,fructose contents in slightly yellowed and green leaves was significantly higher than that in yellowed and dried leaves,however,when the temperature dropped to-25℃,the content of sucrose in slightly yellowed leaves continued to increase and reached 21.11 mg·g-1,which was significantly higher than the other patterns.(3)The lowest low-temperature half-lethal temperature was-26.07℃ in slightly yellowed leaves,followed by-25.19℃ and-24.30℃ in green and yellowed leaves,respectively,and-24.08℃ in slightly dry leaves,and only-22.09℃ in dry leaves.(4)The correlation analysis showed that,among all the sugar indexes,sucrose was able to reflect the cold resistance of the plant in low-temperature environments,whereas the indexes of fructose were relatively poorer.[Conclusion]Low temperature is the main environmental factor that causes yellowing and drying of P.propinqua leaves in Beijing at winter,and the slight yellowed are the most resistant to cold,followed by normal and slight dried leaves of P.propinqua.Sucrose could reflect the cold resistance at low temperatures.
Phyllostachys propinquacold tolerancesaccharidessucroselow temperature