Étude du polymorphisme intraclonal chez le Verticillium albo-atrum, forme à microsclérotes. IV. L'aptitude à varier chez les variants morphologiques

Abstract

The capacity for variation was studied using 10- to 18-month-old cultures of the main variants of two Moroccan isolates of Verticillium albo-atrum R. et B. (microsclerotial form). The hyaline variants were very stable and never returned to the wild type. The other variants gave rise to new variants which differed even more from the wild type but never reverted. A "mixed" type of variant, hyaline but with patches or sectors resembling the wild type, gave rise to wild or hyaline cultures when subcultured, depending on the conditions of transfer. All other variation tended toward a stronger alteration of sclerogenesis without reversing and an irreversible loss of ability to produce microsclerotia (hyaline cultures).