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THE ORIGIN OF AGROPYRON ALBICANS
Author(s) -
Dewey Douglas R.
Publication year - 1970
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.1537-2197.1970.tb09786.x
Subject(s) - agropyron , biology , hybrid , ploidy , botany , introgression , elymus , repens , corpus albicans , backcrossing , candida albicans , genetics , poaceae , gene
Previous suggestions of introgression between Agropyron spicatum (Pursh) Scribn. & Smith, 2n = 14 & 28, and Agropyron dasystachyum (Hook.) Scribn., 2 n = 28, were confirmed. Fertile, meiotically regular, 28‐chromosome plants morphologically identical to Agropyron albicans Scribn. & Smith, 2n = 28, occurred in first‐ and second‐generation open‐pollination progenies of diploid A. spicatum × A. dasystachyum hybrids, presumably by backcrossing to A. dasystachyum . These A. albicans ‐like derivatives were fully cross‐compatible with naturally occurring A. albicans . First and second generation open‐pollination progeny of tetraploid A. spicatum × A. dasystachyum F 1 's contained approximately 5% A. albicans‐like plants; but none was tetraploid, cytologically stable, and fertile. Although introgression occurs freely between tetraploid A. spicatum and A. dasystachyum , derivation of fertile true‐breeding A. albicans from their early‐generation progeny seems unlikely. Agropyron griffithsii Scribn. & Smith ex. Piper, the glabrous counterpart of A. albicans , probably originated from hybrids between diploid A. spicatum and Agropyron riparium Scribn. & Smith, the glabrous form of A. dasystachyum . Genome formulas of diploid A. spicatum, A. dasystachyum (riparium) , and A. albicans (griffithsii) may be written as S 1 S 1 , S 2 S 2 XX, and S 1‐2 S 1‐2 XX, respectively. The relationship between A. albicans and A. dasystachyum is so close that A. albicans should be regarded as no more than a subspecies of A. dasystachyum .