Effect of soil contamination and antibiotics application on growth and some physiological traits of beans in greenhouse condition

The purpose was to specify the impacts of amoxicillin, cefixime, and metronidazole on sunray cultivar of green bean (Phaseolus vulgaris L .) growth and some of its metabolites, which were cultured in soils with various quantities of heavy metals.

For evaluation of the effects of the antibiotics (i.e., Amoxicillin, Cefixime, and Metronidazole) on plant growth, the Antibiotics were tested in 2 doses of 100 and 200 mg.kg-1 soil, and zero for the control. After 42 days fresh and dry weights of green bean shoots and roots were analyzed, and before harvesting the quantity of Chlorophyll (Chl) a, Chl b, Carotenoid (Car), Flavonoids, Phenol, and Antioxidant activity in P. vulgaris leaves were measured.

Green bean treated with Amoxicillin (200 mg.kg-1) produced the highest root dry weight in mine soil (42.91% increase compared to control) while it treated with cefixime (200 mg.kg-1) produced the highest shoot dry weight at rangeland soil (19.21% increase compared to control). The quantity of Flavonoids (18.91%), Phenol (19.70%), Chl a (37.72%), and total Chl (37.40%) in the leaves of the plant with 200 mg.kg-1 Metronidazole reduced in compared to their controls. The results showed that antioxidant activity in green bean tissues was enhanced in mine soil compared to agricultural and rangeland soils (37.76% and 18.43% respectively).

Though soil contamination with heavy metals and the usage of metronidazole had stressful results on green beans, these were not additive or synergetic. Residues of Antibiotics often enter agricultural soils through animal manure, so it is suggested to use at least decomposed manure to control their stressful effects and the arrival of Antibiotics into the food chain.