关键词: 草地早熟禾, 干旱胁迫, 肌醇, 抗氧化酶系统活性

Abstract: Analysis of the differences in antioxidant properties of Poa pratensis Linn. after spraying exogenous myo-inositol (MI) can provide a theoretical basis for improving drought tolerance of Poa pratensis L. In this study,‘Kentucky’,a variety of Poa pratensis L.,was used as the material. After 40 days of seedling emergence,5 concentrations of MI solution were sprayed on the leaves,respectively,and the soil was subjected to natural water loss and drought stress after 5 days of spraying MI. The physiological indexes such as phenotype,chlorophyll content,hydrogen peroxide content and antioxidant system enzyme activity of plants treated with different concentrations of MI solution were observed under 6 drought stress times. The drought tolerance of Poa pratensis L. after MI treatment was evaluated by principal component analysis,correlation analysis and membership function. It was found that spraying MI could slow down the degradation of chlorophyll content,reduce the production of oxygen radicals and the accumulation of malondialdehyde,and increase the activity of antioxidant enzyme system. Correlation analysis showed that chlorophyll,oxygen radical and other indicators were related to the drought resistance of Poa pratensis L. and there was a significant positive correlation between chlorophyll and oxygen radical content and antioxidant enzyme system activity. The study preliminarily determined that spraying exogenous inositol treatment could improve the drought resistance of Poa pratensis L. and the leaves showed the best drought resistance under 400 mg·L^-1 MI treatment.

Key words: Poa pratensis L., Drought stress, Myo-inositol, Activities of antioxidant enzymes