Effect of Polyploidization On Pollen Viability and Inflorescence Morphology in Prairie Cordgrass.

Prairie cordgrass is a multiple cytotype species having three cytotypes: tetra, hexa-, and octoploids. In previous studies, we have observed two distinct hexaploid cytotypes of recent origin: one observed as a seed collected from a single tetraploid population and another from a mixed-ploidy population co-occurring with tetraploids in a single location in IL. Establishment of neopolyploid may result in novel morphological traits, which can contribute to a competitive advantage over their progenitors. In this study, we have examined the pollen viability and morphological characteristics of pollen and inflorescence in tetra (4) and hexaploid (4) populations. We observed a significant cell size increase in higher ploidy level with that the pollen size of hexaploids was larger than tetraploid pollens.  We evaluated inflorescence morphological characteristics of tetraploid and hexaploid prairie cordgrass and found that a significant morphological variation was observed between and among cytotypes.