Twenty-nine reciprocal translocation lines were newly developed by 60Co gamma-ray irradiation (20, 40 and 60 kR) to air dried seeds of 6-rowed barley cultivar, Chikurin Ibaraki No. 1, with the exposure rate of 1 kR/h. Various cross- combinations were made among them, and each of tester lines for translocated chromosomes, which were provided by Dr. R. T. Ramage, were crossed to them.
Chromosome pairings of these F1 hybrids were determined by observing preparations made by the ordinary aceto-carmine squash method. As shown in Table 1, the translocated chromosomes of 27 lines were successfully identified. Break points of these lines were analyzing by Giemsa C-banding technique in progress.
