PEG-6000模拟干旱胁迫对冷季型草坪种子萌发特性影响

ttttt目的ttttt探明冬樱花在干旱胁迫下的适应性。ttttttttttttt方法ttttt通过5%、10%和20%的PEG-8000模拟干旱胁迫，每隔2 d对冬樱花幼苗叶片生理指标进行测定。ttttttttttttt结果ttttt随PEG质量分数的增加和胁迫时间的延长，叶片电解质外渗率持续上升，重度干旱胁迫(20%)的上升趋势最明显，第8天时比第0天上升了189.21%，差异显著(P<0.05)；丙二醛含量总体上升，轻度干旱胁迫(5%)上升趋势较缓慢，中度干旱胁迫(10%)和重度干旱胁迫(20%)上升明显，第8天时分别比第0天上升了25.59%、55.78%和145.25%；可溶性糖含量出现不同程度的上升，轻度干旱胁迫的上升趋势最慢，重度干旱胁迫的上升趋势最明显，第8天时分别比第0天上升31.26%和87.78%；叶片相对含水量在胁迫过程中不断下降，重度干旱胁迫时下降最明显，第8天时比第0天下降了41.62%。相关性分析表明：电解质外渗率、丙二醛含量和可溶性糖含量之间呈极显著正相关，叶片相对含水量与电解质外渗率、丙二醛、可溶性糖均呈极显著负相关。tttttttttttttttttt结论ttttt冬樱花叶片的生理变化说明其幼苗抗旱性较差。tttt

Tree responses to drought

tttttPurposetttttIn order to study the adaptability of Cerasus cerasoides under drought stress.ttttttttttttttttttMethodtttttThrough simulation drought stress by different polyethylene glycol (PEG-8000) treatments (5%, 10% and 20%), the physiological changes of leaves every 2 days were tested.tttttttttttttResulttttttThe relative conductivity in leaves continued to rise with the increase of PEG content and the prolongation of stress time. The relative conductivity in leaves increased significantly in the severe drought stress (20%) compared with the other two treatments, with a promotion of 189.21% after 8 days (P<0.05). The content of malondialdehyde (MDA) also showed an upward trend in all treatments. The change of MDA in mild drought stress (5%) treatment was relatively slow with an increase of 25.59%, while those in moderate drought stress (10%) and severe drought stress treatments (20%) increased more significantly by 55.78% and 145.25% respectively after 8 days. The content of soluble sugar increased under drought stress, and the increase in mild drought stress was the slowest, rising by 31.26% after 8 days, while that in severe drought stress increased by 87.78% after 8 days. The relative water content (RWC) showed a decrease trend, and in severe drought stress the leaf water content decreased by 41.62% after 8 days, which was much more significant than the other two treatments. Correlation analysis showed that the relative conductivity, MDA content and soluble sugar content were positively correlated, and leaf water content was negatively correlated with conductivity, MDA and soluble sugar.ttttttttttttttttttConclusiontttttThe physiological changes in the leaves of C. cerassoides indicate that the drought resistance is poor in seedlings.ttttttttt