Ploidy Characterization of Axonopus By Meiotic Chromosome Counts and Flow Cytometry

Carpetgrasses (Axonopus spp.) have been used as home lawn, sports, and amenity turfgrasses in many locations around the world. Only limited efforts have focused on genetic improvement of Axonopus for turf. Before initiating any genetic improvement program, knowledge of ploidy differences within and among species in a germplasm collection is critical. We evaluated the ploidy variability in Axonopus compressus (Sw.) P. Beauv, Axonopus furcatus (Flüggé) Hitchc., and Axonopus fissifolius (Raddi) Kuhlm. using flow cytometry and meiotic chromosome counts. Meiotic chromosome observations combined with flow cytometry histograms results show that, within our collection, all genotypes of A. compressus were 2n = 4x = 40, one genotype of A. furcatus was 2n = 4x = 40, and all genotypes of A. fissifolius were 2n = 8x = 80 chromosomes. Although a detailed meiotic analysis was not conducted, photographic evidence supports the finding that meiosis, even in the high-chromosome-number A. fissifolius, was regular with very few cytological aberrations.