Changes in chlorophyll content of herbaceous ornamental plants in soil contamination compounds of cobalt and manganese

Abstract

The influence of heavy metals on the photosynthetic apparatus of plants is an independent and very urgent problem. Similar research is actively conducted in many laboratories around the world. However, differences in the types of plants, used salts of heavy metals, their concentrations and processing conditions lead to difficulties in comparing and summarizing the experimental material. In this regard, we studied the negative impact of soil contamination with compounds of cobalt and manganese content on photosynthetic pigments in seedlings of the studied species of herbaceous ornamental plants. The objects of our study were fifteen species of herbaceous ornamental plants. The research was conducted according to the scheme of full two-factor three-level experiment. Cobalt sulfate and manganese sulfate with a concentration of 0–3 g / kg of manganese and 0–10 mg / kg of cobalt were used as pollutants. The number of green pigments was determined by measuring the optical absorption of light in the solution at a given wavelength of light using a spectrophotometer. The data were subjected to statistical analysis by using two-factor analysis of variance. Comparison of average was carried out by the Danneta method. In terms of reduction of chlorophyll the most sensitive species are Alyssum maritimum Lam., Dahlia variabilis Desf., Echinacea purpurea L., Linum usitatissimum L., Calendula оfficinalis L., Petunia Hybrida Grandiflora, та Phacelia tanacetifolia L Almost in all variants of contamination the reduction of chlorophyll a, especially in case of complex introduction of metal were detected. In all versions of pollution in seedlings Agrostis vulgaris there was an increase of chlorophyll content as compared with control plants. A positive trend of increasing concentration with increasing pigment concentration of pollutants was observed. In terms of reduction in chlorophyll content the most resistant species have been allocated: Cosmos sulphureus Cav., Agrostemma githago L., Atriplex hortense L., Silene coeli rosa L., and Tagetes erectus L. The analysis of the number of both chlorophyll impact cobalt and manganese ions indicates that contamination has a stronger effect on the content of chlorophyll a. Many more species of ornamental herbaceous plants studied appeared relatively resistant to the pollution indicator of chlorophyll в content. Rather resistant to the action of pollutants considering the chlorophyll content in seedlings appeared Zinnia aqnustifolla H. and Salvia splendens. The most sensitive for chlorophyll content in seedlings appeared Ageratum houstonianum cv. Bule Lagoon, Alyssum maritimum Lam., Dahlia variabilis Desf., Echinacea purpurea L., Linum usitatissimum L., Calendula оfficinalis L., Petunia Hybrida Grandiflora and Phacelia tanacetifolia L. A possible decrease in the concentration was recorded in all variants of the complex action of heavy metal ions, especially at high concentrations of pollutants. Recent studies indicate the concentration of chlorophyll a in seedlings of ornamental herbaceous plants under soil contamination with compounds of cobalt and manganese changes, but these changes depend not only on the composition of pollutants, but also on the specific characteristics of the type.