Allelopathic effect of Polygonum aviculare on the development and tolerance to salt stress of common flax

The aim of the study is to investigate the allelopathic effect of Polygonum aviculare L. extracts on the development of Linum usitatissimum L. seeds and seedlings, as well as the tolerance of this species to salt stress at the early stages of ontogenesis in vitro. Objectives: to evaluate the effect of aqueous extracts of various concentrations obtained from P. aviculare leaves on seed germination, as well as a number of early developmental parameters of L. usitatissimum seedlings (weight, length of the main root and hypocotyl) under salt stress caused by NaCl solution and in the absence of salt stress, comparing these values with the control. The object of the study was the leaves of Polygonum aviculare L., the allelopathic activity of which was determined using a standard technique on the seeds and seedlings of higher plants. The initial aqueous extract was successively diluted with distilled water in ratios of 1 : 20, 1 : 40, and 1 : 80. The aqueous extracts of the corresponding concentrations were added to Petri dishes containing flax seeds; a 0.05 M NaCl solution was added to half of the dishes. Germination and morphometric parameters of the seedlings were determined daily, starting from 48 hours of cultivation, for 5 days. The maximum extract concentration in the absence of salt stress resulted in a significant decrease in root and hypocotyl weight, length, and length, but decreasing it to 1 : 40 and 1 : 80 resulted in a significant increase of up to 10–12 % (P < 0.05) in these parameters relative to the control. Exposure to medium and low extract concentrations under salt stress resulted in an increase in seed germination, seedling weight, and hypocotyl and root length to the initial control values. A higher (1 : 20) extract concentration did not have a similar stimulating effect. The identified allelopathic stimulating effect of P. aviculare requires further evaluation under in vivo conditions.