The purpose of research is to assess the possibility of determining the ecological state of the Salgir River at places with different anthropogenic pressure intensity by the method of biotesting, ie, to determine the effect of pollutants in water on the tests-responses of bioindicator – bulb onion. The choice of the object of research – water of the river Salgir – was based on the fact that the anthropogenic pressure on the ecosystem of river is constantly increasing, as the change in water quality along the length of the river indicates. The main problems of the Salgir are: the increasing water withdrawal from the river and discharge of insufficiently treated sewage-, rain- and meltwaters. The choice of the subject of research was based on the fact that in recent years, the use of plants for water biotesting has been applied in various areas of environmental monitoring. The test using Allium cepa was recommended by the World Health Organization experts as a standard for environmental monitoring. It is the simpliest in carrying out experiments, available at price, and can also be used as an indicator of mutagenity, since this bioindicator approaches the culture of human cell culture by sensitivity. The phytotoxicity of the tested waters manifested itself in the inhibition and stimulation of the development of root and leaves of onions, as well as in the morphological changes (branching) of roots in all water samples, except for control (distilled water). The results were completely consistent for all 10 replicates. The experiment showed the application perspectiveness of test-plants with prolonged contact with the investigated waters as a sensitive criterion for biotesting of surface waters contamination with pollutants. The results obtained will be taken as a basis for further research in monitoring the state of Crimea's water bodies.
Key words: the Salgir river, water quality, monitoring, biotesting, Allium cepa, bioindicator, toxicity.
