Ploidy level and somatic chromosome number variation in Agrostis stolonifera

Agrostis stolonifera is a polyploid complex in which clonal propagation is predominant. Polyploidization often results in the induction of chromosomal aberrations at the mitotic and/or meiotic level. We observed that variation in ploidy level was present in Agrostis stolonifera, and that variation in chromosome number within genotypes also occurred. Populations differed in the degree of variation observed. Analysis of the frequency distribution of chromosome numbers per cell among different populations showed a wide range of variation in the inland meadow population, an intermediate level in the polder and salt marsh populations, and a very low level in the sand dune population. The results are discussed in the context of the origin of somatic chromosome number variation.