| The amphidiploid MuMuDD
and its hybrids with Aegilops ventricosa K. MATSUMOTO, M. SHIMOTSUMA and M. NEZU Kihara Institute for Biological Research, Yokohama, Japan In 1942 Matsumoto and Kondo have reported on amphidiploids from the hybrid Ae. squarrosa (DD) x Ae. uniaristata (MuMu) and its reciprocal. These amphidiploids were lost during the war time. We have succeeded in producing an amphidiploid MuMuDD again in 1954 from the same combination, Ae. uniaristata x Ae. squarrosa, by colchicine method. The chromosome pairing, percentage of pollen-and seed-fertility of the amphidiploid (MuMuDD) are given in Table 1. The morphology of the amphidiploid (MuMuDD) is fairly similar to that of Ae. ventricosa. Reciprocal crosses with Ae. ventricosa were made for testing the chromosome homology (Table 2). 5-14 (mode 12) bivalents were observed, and among them 2-5 were strongly associated. Complexes were found in many PMC's. The pollen-fertility was very low and no seed was obtained by selfing, while a few seeds were obtained by open pollination (approximately 4%). Morphological comparison between the amphidiploid and Ae. ventricosa is given in Table 3. In 1949 Kihara concluded from a karyological investigation of the hybrid Ae. triaristata x Ae. columnaris that the genome Mt of triaristata is very similar to the columnaris genome Mo. From karyological and morphological points of view, it is concluded that the amphidiploid MuMuDD mostly resembles Ae. ventricosa. (Received April 10, 1957) |