blooms associated by their toxins have been increasing in frequency in fresh
water bodies throughout the world. Among the cyanobacterial toxins,
microcystins (MC) are the most common and cause severe adverse impacts on
plants, aquatic organisms and human beings. In this study, the effects of MC
(at the concentrations of 20 and 200 μg·L-1) from field water and
crude extract of cyanobacterial scum (mainly Microcystis spp.) from the Dau Tieng Reservoir, Vietnam, on the
seedlings of three plants, Brassica rapa-chinensis, B. narinosa and Nasturtium
officinale, were investigated for over a period of 7 days. The results
showed that MC reduced the fresh weight, root and shoot length of the exposed
seedlings. In addition, abnormalities of leaf shape and color of B. rapa-chinensis under exposure to MC were observed. The results implied that MC were taken up
and might be accumulated in the seedlings possessing potential risk to
consumers as seedlings of these plants are a common food source for Vietnamese.
To the best of our knowledge, this is the first report on the effects of MC on B. rapa-chinensis, B. narinosa and N. officinale.