Cytophotometric determination of the nuclear DNA content of 23 Mexican and 18 non-Mexican isolates ofPhytophthora infestans

摘要: The nuclear DNA content of zoospores ofPhytophthora infestans was determined by Feulgen cytophotometry. Isolates from Mexico, where the sexual stage fungus is common, were compared with isolates United States and Europe. mean 23 Mexican 0.59 arbitrary units (a.u.; range, 0.48–0.79), while that 18 non-Mexican 0.92 a.u. (range, 0.56–1.11). are very likely diploid, as indicated cytological studies other workers. group, contrast, appears to include triploid, tetraploid, aneuploid. Of three contents similar those (apparent diploids), two originated Southern California may be recent origin.