Effect of polyethylene microplastics on seed germination of Blackgram (Vigna mungo L.) and Tomato (Solanum lycopersicum L.)

Abstract

Microplastics are emerging contaminants in terrestrial ecosystems which could potentially affect the crop growth. Amongst various crop growth stages, seed germination is one of the prime factors which determines the success of a crop and remains unexplored. Hence, an experimental study was conducted to observe the influence of different concentrations (0.25, 0.50, 0.75 and 1.0%) of polyethylene (PE) microplastics on blackgram (Vigna mungo L.) and tomato (Solanum lycopersicum L.). Results indicate that after 24 hours of exposure, there was a reduction in germination rate from 83.33% in control to 66.67% in treatment with application of 1.00% PE microplastics in blackgram; while in tomato the effect was minimal. Similarly, the rate of root length in blackgram declined in the initial 24 hours. Nonetheless, after 48 and 72 hours of exposure the germination rate and root length was almost similar to the control. However, in tomato, PE-MPs exhibited minimal influence on root growth and no impact on shoot growth. Thus, the effect of microplastics on seed germination, root and shoot length is dose-, species- and time-dependent. Hence, the present study confirms that microplastics can exhibit transient effect on seedling emergence in both blackgram and tomato.