roots

Growth inhibition study that experimentally exposed duckweed (Spirodela polyrhiza) to 50nm and 500nm plastic particles in concentrations ranging from 102 to 106 particles mL-1 for 120 hours and compared these to non-exposed control organisms, with 8 replicates per exposure treatment. The root length was recorded at 0 hours and 120 hours of exposure by transferring single plants onto millimeter paper and taking a vertical photograph using a USB microscope (Dino-Lite USB, AnMo Electronics Corporation, New Taipei City, Taiwan). The root length was measured with a precision of four digits on the acquired images employing Fiji (Schindelin et al., 2012), and the root number was determined manually.