Effects of cadmium and lead concentrations and arbuscular mycorrhiza on growth, flowering and heavy metal accumulation in scarlet sage (Salvia splendens sello 'torreador')

Abstract

The objective of this research was to examine the influence of Cd (0, 10, 20, 40 mg Cd·dm^-3) and Pb (0, 10, 100, 200 mg Pb·dm^-3) in growing substrate and mycorrhizal colonization of root system on growth, flowering, Cd and Pb accumulation in scarlet sage shoots. Both Cd and Pb had a negative effect on mycorrhizal colonization of scarlet sage roots. The effect of Cd and Pb on the growth of scarlet sage was negligible. Cd at 40 mg·dm^-3 lowered the number of inflorescences and caused slight chlorosis of the lowermost leaves. Pb at 200 mg·dm^-3 caused drying of the lowermost leaves. Both heavy metals accelerated flowering of non-mycorrhizal plants, independently of the concentration in growing media. Cd and Pb contents in scarlet sage shoots increased with the increasing content of these heavy metals in growing substrate in both non-mycorrhizal and mycorrhizal plants. Mycorrhization decreased the growth of scarlet sage and increased the accumulation of Cd and Pb in shoots of plants grown in media strongly polluted with heavy metals.