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Comparison of common cytotypesof Andropogon gerardii(Andropogoneae, Poaceae)
Author(s) -
Keeler Kathleen H.,
Davis Geoffrey A.
Publication year - 1999
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 - 10.2307/2656614
Subject(s) - andropogon , biology , polyploid , poaceae , population , botany , ploidy , biochemistry , demography , sociology , gene
Many plant species contain populations with more than one polyploid cytotype, but little is known of the mechanisms maintaining several cytotypes in a population. Andropogon gerardii cytotypes were compared to evaluate different models of autopolyploid cytotype coexistence. The enneaploid (90 chromosome, 9 x ) cytotype was found to be larger and taller than the hexaploid (60 chromosome, 6 x ) cytotype. Seed production is significantly more efficient in hexaploids, but seed production per area was not significantly different. The two cytotypes are not exomorphologically separable in the field because of great plasticity in response to environmental variation and wide variation within each cytotype. These data suggest cytotypic variation is maintained by natural selection.