[Effect of Polyvinyl Chloride Microplastics on the Growth and Physiology Characteristics of Strawberry].

Abstract

In recent years, there has been an increasing number of reports on the environmental impact caused by the accumulation of microplastics in soil. However, there is limited research on the comprehensive effects of microplastics on the physiology, growth, soil characteristics, enzymes, and nutrients throughout the entire lifecycle of plants. To investigate the influence of soil microplastics on strawberry growth, the effects of different particle sizes and concentrations of polyvinyl chloride microplastics （PVC-MPs） on the germination rate and germination time of strawberry seeds, as well as physiological indicators and the physicochemical properties of the soil during strawberry growth, were elucidated through germination experiments and pot experiments. The results indicated that the addition of PVC-MPs led to a 4%-12% decrease in strawberry seed germination rate and delayed germination time. PVC-MPs may have caused oxidative stress in strawberries, reducing chlorophyll content in leaves, stimulating the release of superoxide dismutase （SOD） and peroxidase （POD） in the antioxidant defense system of plants and reducing cell damage. The addition of 5% PVC-MPs significantly inhibited the activity of β-glucosidase （BG） and leucine aminopeptidase （LAP） in the soil while enhancing the activity of β-1,4-N-acetylglucosaminidase （NAG） and acid phosphatase （ACP）. The addition of high concentrations of PVC-MPs increased soil porosity and reduced the content of available phosphorus （AP） and the content of soil organic carbon （SOC）, which decreased by 39.3-48.9 g·kg^-1 compared with that in the control group. The content of nitrate nitrogen （NO₃^－-N） of the treatment adding 5% 20 μm decreased by 52%, and the content of ammonium nitrogen （NH₄⁺-N） increased by 50%. These results indicate that PVC-MPs can alter soil structure, affect soil nutrients, and have a certain interference effect on strawberry growth and development. The research results can provide a reference basis for evaluating the ecological risk of PVC-MPs.