Germination of seeds and development of sprouts of Bidens (Asteraceae) species representatives in coppersulfate solutions

The influence of copper sulphate (0.1-50 mg/l) on germination ofseeds and the initial stages of development of sprouts of plants of damp habitats is studied: Bidens tripartita L., B. cernua L. and B.frondosa L. The seeds of all the three kinds possessed high viability; under control they had laboratory germination of 83-97%. Theseeds of B. tripartita were steady against the action of the toxicant in all the specified intervals of concentration. Copper sulphate solutionsstimulated their germination, but did not influence essentially the laboratory germination. The seeds of B. frondosa possessed thegreatest sensitivity to the investigated solutions: all concentrations of copper slowed their germination, which resulted in lower laboratorygermination. The dynamics of germination and laboratory germination of the seeds of B. cernua were considerably affected by thecopper sulphate at a concentration of 50 mg/l. The identical toxic effect of the copper sulphate on the development of sprouts has beennoted with B. cernua and B. frondosa, however, none of the investigated concentrations caused full suppression of their formation. Thedevelopment of sprouts of the investigated species is decreasing as follows: B. tripartita> B. cernua> B. frondosa. Copper ions madethe greatest toxic effect on the growth and development of the root system of sprouts of all the investigated kinds; however, it wasshown differently. The authentic decrease in length of the main root of B. tripartita and B. frondosa sprouts is registered at a concentrationof copper of 10 mg/l. With this concentration, the main root of sprouts of B. cernua did not develop. The main root of B. frondosadid not develop at a concentration of 25 and 50 mg/l. Necrosis of the main root was not observed. Necrosis of additional roots of B.tripartita and B. cernua was observed at a concentration of 10-50 mg/l. Additional roots of B. frondosa were normal at a concentrationof 10 mg/l, at 25 mg/l they were in embryo and did not develop at the maximum concentration. The elevated part of sprouts reacted tothe raised concentration of copper in the environment to a lesser degree, the morphometric indicators authentically did not differ fromthe control at all concentrations. Necrosis of B. cernua hypocotyl began at a concentration of 50 mg/l. B. tripartita and B. frondosa didnot show necrosis. All kinds showed partial necrosis of the cotyledon at the maximum concentration of copper. By results of our research,it is possible to recommend application of copper sulphate in low concentration for struggle against the distribution of invasivespecies of B. frondosa.

Keywords

Authors

References