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MALE GAMETOPHYTE SELECTION IN A NATURAL POPULATION OF HAPLOPAPPUS GRACILIS (COMPOSITAE)
Author(s) -
Jordan Robert G.
Publication year - 1975
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1975.tb14078.x
Subject(s) - biology , gametophyte , sporophyte , gynoecium , population , chromosome , natural selection , pollen , natural population growth , karyotype , botany , genetics , gene , stamen , demography , sociology
Distributions of two forms of the A chromosome of Haplopappus gracilis in a hybrid natural population and in artificial crosses are analyzed. Pollen bearing the standard type A chromosome is generally superior to that bearing the Mexican type A when they compete on homozygous pistils of either type, but there is no selection on heterozygous pistils. The distribution of sporophyte karyotypes in the natural population is not in equilibrium, and it is surmised that the standard type A chromosome is increasing in frequency in the population.