Effects of Eichhornia crassipes Growth on Aquatic Plants in Dianchi Lake

[Objective] The aim was to study the effects of Eichhornia crassipes as an invasive plant on aquatic plants in Dianchi Lake. [Method] Based on the determination of chlorophyll content of phytoplankton and submerged plant (Potamogeton pectinatus) in Dianchi Lake in different months, the effects of E. crassipes on aquatic plants in Dianchi Lake were studied, and the allelopathy effect of root culture solution of E. crassipes on Microcystis aquaticum was discussed. [Result] The growth of E. crassipes in Dianchi Lake reduced the chlorophyll content of phytoplankton and submerged plant (P. pectinatus), and it showed that E. crassipes had certain inhibitory effect on their growth; the culture solution of E. crassipes root inhibited M. aeruginosa growth obviously. [Conclusion] The study could provide scientific references for the prevention and control of ecological safety of E. crassipes.

Allelopathic Effect of Adzuki Bean Root Aqueous Extracts on Four Crops

For choosing suitable summer-planting adzuki bean crop, this experiment adopted the method of indoor petri dish bioassay to study the allelopathy effect of adzuki bean, radish, cabbage and wheat under different concentrations of adzuki bean root aqueous extracts. The result showed that the adzuki bean had a strong inhibition towards its germination rate and germination index. With the increasing concentration of the adzuki bean root aqueous extract, the seed germination rate and germination index of the three kinds of receptor crops presented a decreasing trend. From the root length, spire length, the number of lateral roots, plant height, fresh mass and other morphological indexes of seedlings, it was concluded that with the increase of concentration of adzuki bean root aqueous extract, only wheat pre- sented a promotion effect while the other two kinds of receptor crops showed an inhibition effect, which were not significant at low concentrations. With the increase of concentration of adzuki bean root extracts, the SOD and POD activities of radish and wheat also increased, while the two kinds of enzyme activities of cabbage showed a decreasing trend. The MDA contents in seedlings of radish and wheat decreased, while the MDA content in cabbage increased significantly, which showed that wheat could be used as a rotation crop of adzuki bean, and radish also had a great application potential in adzuki bean crop rotation.