Analysis of Ploidy Levels in Strains of Verticillium using a Coulter Counter

Abstract
V. dahliae and V. albo-atrum are predominantly haploid deuteromycete pathogens. Both species form verticillate conidiophores and develop darkly pigmented resting structures. The feasibility of utilization of a Coulter counter for reliably estimating the ploidy levels of large populations of conidia of V. albo-atrum and V. dahliae was evaluated. Spore size was considered a convenient criterion for reliable estimation of ploidy level.