| I. Research Notes Identification of reciprocal translocation chromosome types in the emmer wheats. II. Thirty eight strains of Triticum dicoccoides Korn. with the fundamental chromosome structure.1) TAIHACHI KAWAHARA Plant Germ-plasm Institute, Faculty of Agriculture, Kyoto University, Mozume, Muko, Kyoto 617, Japan In the first paper of this series, Kawahara & Tanaka (1978) analyzed 22 strains of Triticum dicoccoides Korn. and found three chromosome types which differed by reciprocal translocations. This paper reports on the configurations of chromosome pairing in hybrids between strains of T. dicoccoides with the E1 type chromosome structure. The materials used were 38 strains of T. dicoccoides from Israel, Syria, Turkey, Iraq and Iran (Table 1). Two tester strains of the earlier repoer (Kawahara & Tanaka 1978), 108-3 and 108-5, were also used. Chromosome pairings were observed at first metaphase (MI) of the pollen mother cells with the aceto-carmine or aceto-orcein squash technique. In total, chromosome pairings of 70 hybrids were analyzed. Table 2 shows the percentage of cells with multivalents in the F1 hybrids. Results obtained by Kawahara & Tanaka (1978) are included in the table for comparison. It is clear from Table 2 that most of the hybrids showed little or no multivalents at MI. This indicates the absence of a major reciprocal translocation between the two parental strains. In seven hybrid combinations, however, the frequency of multivalents (trivalents and quadrivalents) was rather high, i.e., more than 30 percent. The combinations were 1921 x 108-2, 1978B x 108-3, 8541 x 108-3, 8737 x 108-3, 8816A x 108-2, 8941 x 108-2 and 8943 x 108-3. All of them were hybrids with 108-2 or 108-3. Since the average frequency of multivalents was not so high as that obtained in hybrids heterozygous for major translocations (Kawahara in preparation), these two strains were regarded to have one minor translocation as discussed below. Consequently, the chromosome structure of all the 38 strains listed in Table 1 were grouped into type E1, 18 strains of which were newly identified in the present study. |
| 1) Adapted from a thesis submitted to the Kyoto University, Kyoto (Kawahara 1984). |
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