Cadmium and Nicotine Correlation in Reference to Tobacco Plant Varieties and to Sludge/Soil Applied Ratios

Abstract

Genetic factors are known to alter the incorporation of heavy metals in tobacco plants (TP). We compared nicotine (Ultra Violet Spectrophotometry) and Cadmium (Cd) levels (Atomic Absorption Spectrophotometry), in 2 Greek TPvarieties, Tsebeli (I) and Mirodata Agriniou (II) grown in increasing proportions (0, 10, 20 and 40%) of sludge added to standard soil. Cd levels decreased in variety I and increased in variety II with increasing leaf height (p=0, 000) and a negative correlation between Cd and nicotine levels was confirmed in variety I within the 1 St and 3^rd harvesting periods (r=-0, 643 and r=-0, 630 correspondingly). Cd levels, in both varieties, decreased with increasing proportions of sludge. Nevertheless only plants grown in the 40% sludge/soil proportion showed significantly lower values. A negative correlation between nicotine and Cd was observed, only in variety I and in 10%, 20% and 40% sludge/soil proportions. The two tobacco varieties differ in nicotine dependence on sludge/soil proportion. Variety I presents the minimum of nicotine levels at 20% sludge/soil proportion and the maximum at 40% (p=0, 000), while variety II presents an inverse pattern.It is concluded that tobacco plant genotype may affect heavy metal and tobacco alkaloid interactions, in relation to sludge/soil proportion and thus biodiversity must be taken in consideration in solid waste management.