Expression of heavy metal tolerance in pollen and implications for gametophytic selection. [The plants used were clones of Silene dioica and Mimulus guttatus]

Thesis/Dissertation · Sun Jan 01 00:00:00 EST 1984

OSTI ID:5553500

Searcy, K B

Many genes are expressed in both sporophytic and microgametophytic phases of the angiosperm life cycle. Thus, selection in one phase could modify gene frequency in both phases. An attempt was made to investigate microgametophytic selection in response to toxic concentrations of heavy metals and the effect of this selection upon the resultant sporophyte generation. The plants used were clones of a zinc-tolerant Silene dioica, closely related nontolerant S. alba, and copper tolerant and non-tolerant clones of Mimulus guttatus. First, the expression of metal tolerance in pollen was established by in vitro pollen germination and tube growth, and was found to be associated with the tolerance of the pollen source. Second, to test the extent to which the parallel expression of metal tolerance was determined by the gametophytic genotype, tolerant but segregating clones were grown with and without added metals. Finally, selection was applied during pollen germination, tube growth and fertilization. In Silene, neither the tolerance of the pollen nor the metal content of the styles affected pollen tube growth rate. In Mimulus, pollen from the nontolerant source grew faster, but the metal content of the floral tissue had no significant effect on pollen tube growth rate, and only slightly reduced the fertilization ability of pollen from the nontolerant clone.

• OSTI ID: 5553500
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
COPPER
TOXICITY
POLLEN
GERMINATION
SENSITIVITY
ZINC
CLONING
FERTILIZATION
GENES
PLANT GROWTH
PLANTS
ELEMENTS
GAMETES
GERM CELLS
GROWTH
METALS
TRANSITION ELEMENTS
560303* - Chemicals Metabolism & Toxicology- Plants- (-1987)