Available online
Description
The programme examines the way in which some species of grass have evolved a tolerance to heavy metal contaminated soil.
The programme examines the way in which some species of grass have evolved a tolerance to heavy metal contaminated soil.
| Module code and title: | S299, Genetics |
|---|---|
| Item code: | S299; 11 |
| First transmission date: | 19-07-1976 |
| Published: | 1976 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:24:00 |
| + Show more... | |
| Producer: | Jean Nunn |
| Contributor: | Tony Bradshaw |
| Publisher: | BBC Open University |
| Keyword(s): | Abandoned mines; Genetics; Plant tolerance; Selection |
| Footage description: | Tony Bradshaw, on a railway embankment, introduces the programme. He points out an area of no vegetation and explains that this is due to a heavy concentration of copper in the soil. Bradshaw tests a sample of soil for copper content. Bradshaw at Trelogan, an abandoned lead/zinc mine. He examines an experiment of grasses cultured in solution with and without zinc added. The metal infected grasses show no growth at all. Bradshaw points out some plants which are managing to survive on the mine tailings. He puts forward two possible explanations for their metal tolerance. Bradshaw explains the procedure for an experiment which tests whether or not the species on the tailings and in the pasture are all metal tolerant or if those on the tailings are tolerant while those in the pasture are not. He shows the results of such an experiment. These indicate that pasture species are not metal tolerant, that tolerance is specific to individual metals and that the metal is complexed in the roots of tolerant plants. Bradshaw speculates on the length of time it took for these species to develop heavy metal tolerance. He looks at an experiment which indicates that some metal tolerant plants are present in normal populations so that a metal tolerant population can evolve in one generation. Bradshaw explains why there is a sharp change from non-tolerance to high tolerance in islands of contamination even though the plants are self sterile and wind pollinated. Bradshaw briefly explains why so few species out of the large number in the nearby pasture are found in the contaminated areas. To sum up, Bradshaw points out a practical application of growing metal tolerant grasses - to cover contaminated areas and prevent the spread of contamination by wind and rain erosion. |
| Master spool number: | 6HT/71806 |
| Production number: | 00525_1179 |
| Videofinder number: | 1000 |
| Available to public: | yes |
