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THE HYBRID ORIGIN OF ASTER ASCENDENS (ASTERACEAE)
Author(s) -
Allen Geraldine A.
Publication year - 1985
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.1537-2197.1985.tb08291.x
Subject(s) - biology , asteraceae , advanced spaceborne thermal emission and reflection radiometer , taxon , habit , botany , range (aeronautics) , ploidy , karyotype , chromosome , gene , genetics , geography , remote sensing , digital elevation model , psychology , materials science , psychotherapist , composite material
Aster ascendens Lindl. is a rhizomatous perennial of the Great Basin region of the western United States, with a chromosome base number of x = 13. Populations in the southern and western parts of the range are mainly diploid ( n = 13) and those in the north and east are mainly tetraploid ( n = 26). This species is postulated to be an amphiploid which has resulted from hybridization between the western Cordilleran A. occidentalis (T. & G.) Hook, and the Great Plains species A. falcatus Lindl. Aster ascendens is intermediate between these two species in most morphological traits, but resembles A. occidentalis in ray color and general growth habit, and A. falcatus in the shape of the outer phyllaries. The karyotype of A. ascendens also exhibits a combination of the features found in A. occidentalis and A. falcatus karyotypes. Of the specimens collected for this study, 13% were putative backcrosses of A. ascendens to one of its parent taxa or to a closely related species; this suggests that there is potentially continuing genetic interchange between the species groups that gave rise to A. ascendens .