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Evolutionary implications of meiotic Chromosome Behavior, Reproductive Biology, and Hybridization in 6X and 9 X Cytotypes of Andropogon gerardii (Poaceae)
Author(s) -
Norrmann Guillermo A.,
Quarín Camilo L.,
Keeler Kathleen H.
Publication year - 1997
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 - 10.2307/2446081
Subject(s) - andropogon , biology , meiosis , poaceae , chromosome , evolutionary biology , botany , genetics , gene
Andropogon gerardii, big bluestem, has 60 and 90 chromosome cytotypes. Meiosis in the hexaploid was shown to be regular, although some secondary associations of bivalents form. Meiosis in the enneaploid (2 n = 9x = 90) is irregular, leading to most gametes having unbalanced chromosome complements. Both cytotypes show considerable self‐incompatibility. Cytotypes crossed freely, forming a variety of fertile euploids and aneuploids. Indistinguishable exomorphology, intermixing in natural populations, and compatibility suggest that A. gerardii is best understood as a cytotypically complex single species.