Changeability in the pattern of white marking on a leaf of Trifolium repens L. is a bioindicator of presence in soil of agricultural lands of nitrate nitrogen and heavy metals

Abstract

Aim. Conduct research between the variability of the pattern of white marking on a leaf of Trifolium repens L. and the content of nitrate nitrogen and heavy metals in soil of hayfield and pasture. Methods. Collection of leafs was carried out in 2019 during the period of mass flowering of plant. Identification of drawings of white marking on a leaf was carried out according to the method of IT. Paponova and P.Ya. Schwartzman, using the tables of J. L. Briubecker. Soils were tested for nitrate nitrogen and heavy metals in accordance with recommended methods. Results. In the total sample of T. repens L. collected from territories of the hayfield and pasture, detected 8 phenotypes, formed by a series of 7 alleles of gen V. In the sample from the territory of the hayfield, the phenotype O was most often found, in the sample from the territory of the pasture - the phenotypes of AH and C, much more often than in the territory of the hayfields – the phenotype of the BHC. In the hayfield, the frequency of «wild» phenotypes was higher, in the grassland – «mutant» phenotypes. In each of the studied territories unique phenotypes were detected: on the territory of hayfield – phenotype C in the form of a four-leaf, on the territory of the pasture – phenotypes of BHB and E. Pasture soil had a significantly higher content of nitrate nitrogen (almost 4 times), Fe (almost 2.5 times), Mn (1.6 times), Zn (2.4 times), Cu (1.8 times), Pb (more than 2 times) and Cd (more than 2 times) compared to soil of hayfield. Conclusions. A correlation was found between the frequency of T. repens phenotypes detected in the pattern of white markings on the leave and the presence in soil of hayfield and pasture of nitric nitrogen and heavy metals. However, it should be evaluated with caution, as the relationship between these indicators is although probable, but requires further investigation.
 Keywords: Trifolium repens L., white marking on a leaf, bioindicator, soil, nitrate nitrogen, heavy metals.