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A Survey of Apomixis and Ploidy Levels among Poa L. (Poaceae) Using Flow Cytometry
Author(s) -
Kelley Alicia Michelle,
Johnson Paul G.,
Waldron Blair L.,
Peel Michael D.
Publication year - 2009
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2008.09.0553
Subject(s) - apomixis , biology , obligate , poa annua , ploidy , botany , facultative , germplasm , poaceae , sexual reproduction , genetics , gene
Poa is a complex genus taxonomically and genetically. As a result, relatively little information exists for this economically important genus with regards to reproductive mode and variability in chromosome number. We examined apomixis frequency and ploidy levels in 83 Poa accessions representing 33 species from the National Plant Germplasm System using flow cytometric techniques. In reproductive mode analysis, we analyzed at least three preparations of 50 seeds each from the accessions. In ploidy level analysis, at least three plants of each accession were analyzed. Sixty percent of the species had at least one apomictic or facultative apomictic accession; 40% were sexual. Thirty‐three percent of the species had no sexual accessions. Autonomous apomixis was newly identified in P. bactriana and P. bulbosa in addition to it being previously reported in P. nervosa. Poa annua and P. trivialis were identified as obligate sexual, and P. nervosa as obligate apomictic. Two of four P. palustris accessions exhibited facultative apomixis. Ploidy levels among sexually reproducing Poa accessions ranged from 2 n = 2 x = 14 to 2 n = 12 x = 84, with most accessions between 2 n = 3 x = 21 to 2 n = 8 x = 56. Among apomictic accessions, ploidy levels ranged from 2 n = 3 x = 21 to 2 n = 10 x = 70, with most between 2 n = 4 x = 28 and 2 n = 10 x = 70. These results emphasize the wide variability in Poa , both among and within species.