Abstract
After colchicine treatment of F1 Hordeum vulgare seedlings eutetraploid plants were found to produce aneuploids as well as the expected euploid seedlings for three successive generations from F2(C1) to F4(C3). The presence of aneuploids in the progenies of 28-chromosome plants indicates that besides euhaploid gametes aneuhaploid gametes must be functional. Taking this into account and assuming that anaphase distribution in both male and female mother cells follows the same pattern in forming the gametes, chance combinations of gametes are calculated. An explanation of correlation between aneuploidy, seed set and sterility is provided. From the data given it is evident that hyperploids are more vigorous than their corresponding hypoploids and that the number of surviving aneuploids is greatly influenced by environmental conditions. This modifies seed set and fertility of the same material grown under different environmental conditions.[long dash].