Homothallism in Thanatephorus Cucumeris

Evidence is given to support the claim made by seveml workers that T. cucumeris is homothallic. In some isolates the evidence for homothallism is conclusive. However, in other isolatos sterility factors prevent fruiting in otherwise self-fertile progeny and in still other isolates self-fertility of progeny can be accounted for by the frequency of binucleate spores in which both nuclei are immediate meiotic products. The importance of accompanying genetical studies with cytological information is therefore stressed.