Morphological variation within and among five annual Phalaris species

Accessions of annual canarygrass (Phalaris canariensis L.; 2n = 2x = 12) held within germplasm collections generally lack adequate genetic characterization for utilization in crop improvement. The objective of this study was to assess the level of morphological variation of accessions of five annual Phalaris species, including 49 annual canarygrass, 48 P. minor Retz. (2n = 4x = 28), 24 P. brachystachys (2n = 2x = 12), 19 P. paradoxa L. (2n = 2x = 14), and three P. angusta Nees ex Tris. (2n = 2x = 14). In 1993 and 1994, accessions were grown under growth chamber and greenhouse conditions, respectively. Eighteen morphological traits were measured on five plants per accession. Phalaris canariensis had intermediate culm height, wider penultimate leaves, shorter and wider panicles, and larger caryopses relative to the other four species. The six qualitative traits were monomorphic in all five species, except for glume pubescence in P. brachystachysand inflorescence type in P. paradoxa. The limited variation within and among P. canariensis accessions supports the idea that germplasm collecting activities are needed to broaden the genetic diversity held in North American Phalaris collections. Key words: Phalaris, germplasm, morphological traits