The Effect of Heavy Metals in Potato (Solanum tuberosum L.) Genotypes for Some Physiological Parameters

Abstract

The main aim of this study is to identify physiological characteristics, including Chl a, b, total Chl "a+b" and carotenoids, in potato genotypes under the influence of lead (Pb+2) and cadmium (Cd+2) heavy metals. Two potato genotypes from the Netherlands, Riviera and Agria, were used in the study. Potato tubers were transferred to 2 kg compost pots and placed in a controlled environment with a 12 photoperiod, a day/night temperature of 25/19°C and a relative humidity of 75%. Since Pb+2 and Cd+2 poisoning was greater than in the control and different fractions of heavy metal residues in the substrate were transferred to plant organs, the amounts of these two metals in each treatment (outside the control) were measured. Plant pigments were extracted from fresh leaves in amounts ranging from 60 to 100 mg and these were then extracted into samples containing 80/20% (v/v) acetone/water with 0.5% w/v MgCO3 at room temperature for a full day. Photosynthetic pigments of each sample were extracted three times. The absorbances obtained at 663 nm, 644 nm and 452.5 nm for the maximum absorption of Chl a, Chl b and carotenoids, respectively, were used to measure the amount of chlorophyll and carotenoids. Differences between Pb+2 and Cd+2 and physiological markers were examined with the Duncan Multiple Range test. Information on Pb+2 and Cd+2 content in applications revealed wide variability. When potato genotype seedlings were exposed to varying levels of Pb+2 and Cd+2, the amount of chlorophyll and carotenoids in their leaves was lower than the control group. The results showed that there were significant and statistically significant changes in carotenoid and chlorophyll concentration at the LSD p = 0.01 level. Similar to Pb+2 and Cd+2 inhibiting plant growth, it had a negative effect on photosynthesis as well as chlorophyll and carotenoid contents. Moreover, these effects became more pronounced when the concentrations of two stress factors (Pb+2 and Cd+2) increased.