Growth of Serpentine and Non-Serpentine Races of Festuca Rubra in Solutions Simulating the Chemical Conditions in a Toxic Serpentine Soil

Abstract

Soil solutions were extracted by centrifugation from 11 soil samples from a toxic serpentine soil at Meikle Kilrannoch in Scotland [UK]. Analyses showed high concentrations of Mg2+ and NO3-, low ones of Ca2+ and potentially toxic concentrations of Ni2+. Nutrient solutions, with composition based on these analyses were prepared. In them were grown 2 clones of F. rubra; one from the Meikle Kilrannoch serpentine and the other from a non-serpentine acid brown earth. Four experiments with different combinations of Ca2+ and micronutrient concentrations were made. In each the effects of different concentrations most similar to soil solutions from the same site. The acid-soil clone plants grew slowly in this solution. They grew fastest in solutions containing higher concentrations of micronutrients and lower ones of Mg2+, Ni2+ and Ca2+. High Mg2+ concentration appeared to be the main cause of the slow growth of the acid-soil clone in Meikle Kilrannoch soils. However, Ni2+ was toxic also. Both Mg2+ and Ni2+ toxicity were ameliorated by a higher concentration of Ca2+ and to some extent of micronutrients. The amelioration was associated with a reduction in tissue concentration of nearly all the elements analyzed and may involve some restoration of membrane function.