After gamma rays Co⁶⁰ treatment of the six-rowed winter barley cultivars Vogelzanger Gold, Markeli 2, and N 468, and two-rowed winter barley cultivars Alpha, HS 80/18, and Becker, a large collection of different homozygotes translocations has been obtained. They were evaluated using a spring barley tester set T1-5, T2-4, T1-6, T2-3, and T5-7. For synchronization of flowering time, spring lines were sowed in the greenhouse and transplanted in the field where winter translocation lines were grown. The advantage of using a spring tester set in identification of winter translocation is that F₁ crosses may be planted without vernalization in greenhouses.

The winter barley translocation stocks which were identified during this study are listed in Table 1. A tester set of winter barley lines could be selected from these lines.

An analysis of data to compare the translocation frequency and the dose of gamma rays Co⁶⁰ showed that treatment with 10 and 20 kR, but not 30 kR, proved to be most effective. The high dose induced many cases of male sterility instead of semisterility.

Considering the distribution of identified translocations on the chromosomes, it was evident that 22 exchanges involved chromosome 1; 17 for chromosome 6, 15 each for chromosomes 2 and 3, 14 for chromosome 7, 12 for chromosome 4, and 11 for chromosome 5. The exchange frequency may depend on chromosome length, mutagen, genotype, or all of these factors.

Seeds of the translocations in winter type barleys are available from the Institute of Barley, Karnobat-8400, Bulgaria upon request.