Polyploid Sugar Beets—Cytological Study and Methods of Production

It is not quite clear at present whether or not polyploidy could be used to increase the productivity of sugar beets (1, 3, 5) . However, triploids which show heterosis have been developed (2, 3) . Polyploidy increases the size of fruits and germs. This property, which counts for little in multigerm beets, can prove very useful in monogerm beets (4) . To gain the advantages of polyploidy, it is necessary to develop an easy method of obtaining a sufficient number of tetraploid plants. Such methods must be based upon treatment of the growing point in young seedlings, because the growing point can produce pure tetraploid floral axes. Trea tment of the floral axes themselves may cause chimeras or merely islands of 4n tissue. Studies were made to determine the importance of 1. concentration of colchicine solution, 2. duration of treatment and 3. the age of seedlings when the treatment is most effective.