FIELD: agriculture.
SUBSTANCE: invention represents a method for determining the relative resistance of soft spring wheat varieties to the causative agent of ordinary root rot of cereals Bipolaris sorokiniana Shoem by means of treating plant samples with cultivar filtrates of the causative agent containing fungal toxins, characterized in that seedlings grown in a roll culture on tap water up to the phase of 2-3 leaves are used as the plant samples, the test samples of the seedlings are maintained in the culture filtrate of the causative agent in the dilution of 1:1 within 24 hours, the control samples - in distilled water within the same time, cuttings from the middle part of the second leaves of seedlings of control and test samples are made, they are placed in distilled water at the ratio of 1:4 for 1.5 hours under lighting conditions, the extracts are filtered, their conductivity under AC voltage at the frequency of 1 kHz is determined, and the relative resistance of a variety against 
is estimated, where Gk is the conductivity of the aqueous extracts of leaves of the control samples; Go - the electrical conductivity of the aqueous extracts of leaves of the test samples; the smaller the calculated ratio is, the more stable is the variety in the group of soft spring wheat varieties to be estimated.
EFFECT: invention allows to reduce time costs, to reduce the labour intensity of estimating the resistance of wheat varieties at the stage of seedlings, and to carry out differential diagnostics of the resistance of soft spring wheat varieties to the toxic effect of metabolites of the causative agent of ordinary root rot of cereals.
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