Effect of microcystins at different rice growth stages on its yield, quality, and safety

Microcystins (MCs) in water for irrigation may damage crop growth and enter food chains to threaten human health. To evaluate the potential risk of irrigation water contaminated with MCs, we exposed rice at each of the seedling, booting, and filling stages to irrigation water spiked with MCs at 1, 10, 100, and 1000 mu g/L for 7 days. Afterwards, all rice underwent a recovery (without MCs) till the harvest. Low MCs (1 or10 mu g/L) during different rice growth stages did not affect its yield and nutritional quality and had no risk to human health. High-concentration MCs (100 or 1000 mu g/L) during the seedling or booting stage caused a larger decrease in the nutritional quality and yield of rice grains than that during the filling stage. In addition, MCs at 100 mu g/L during the booting stage or at 1000 mu g/L during the filling stage potentially threatened human health. The effect of MCs on rice yield, quality, and health risk was associated with the MC concentration and rice growth stage. Irrigation water contaminated with moderate-concentration MCs should be of concern at the early growth stage of rice.

Automated summary

Research suggests that low concentrations of MCs do not affect rice yield and quality, and pose no risk to human health; high concentrations of MCs may lead to decreased rice yield and quality, posing a threat to human health; the impact of MCs is influenced by concentration and rice growth stage.