GENETIC-CONTROL OF COPPER TOLERANCE IN SILENE-VULGARIS

The genetic control of heavy metal tolerance in higher plants is poorly understood, possibly in part because of several inherent properties of tolerance tests and tolerance measures. In this study we compared different methods of testing for copper tolerance in Silene vulgaris. A new type of multiple concentration test has been used to analyse the genetic control of copper tolerance in this species. Provisional results indicate that the occurrence of any tolerance, relative to a non-tolerant reference population from uncontaminated soil, is governed by a single major gene. The level of tolerance, however, seems to be controlled by a number of modifiers, which are completely hypostatic to the major gene. This model agrees with that proposed for Mimulus guttatus by Macnair (1983).