Prevention of gene erosion of old wheat varieties by back-crossing and X-ray irradiation

The famous old Tisza riverside wheat varieties have several characteristics which are very valuable in modern plant breeding, the most important being their high protein content. The recently cultivated varieties contain 13-14%, whereas the old ones had 17-18% protein. Their winter hardiness and baking quality are also outstanding. Their preservation in the original form is very difficult. The fact that many thousand collected forms are sown in small plots (1-2m2) in the Agrobotanical Institute, Tapioszele, facilitates biological and man-caused accidental mixing. If the height of the old varieties is decreased and their stalk strength increased, varieties with high practical value are obtained. One way to breed dwarf varieties has been by back-crossing, as was done with Ble Tom, Norins, Oleson, etc. Another way has been by X-ray irradiation (10kR treatment for dry seeds). With this method a new homozygote dwarf (70-90cm) form of Bankuti 1201 was bred. The new mutant has almost all the characteristics of Bankuti 1201, but its stalk is shorter by 50-70cm than that of the original one. At the same time the disease resistance (stem rust and mildew) of the dwarf form is usually better than that of the old tall types. It seems that one of the most modern ways to prevent gene-erosion is through this type of ''transformation''. (author)