| Analysis of chromosome pairing in interspecific F1
hybrids involving Aegilops Juvenalis R. C. MCGINNIS and J. H. MELNYK Department of Plant Science, University of Manitoba and Children's Hospital, Winnipeg, Canada A large number of interspecific and intergeneric hybrids involving Aegilops species were produced and cytologically investigated while the authors were on staff at the Cereal Breeding Laboratory, Winnipeg. The major objective was to determine the genome constitution of the hexaploid species. In 1958, KIHARA, YAMASHITA and TANAKA published the results of their work in which the genomes of the three hexaploid species were designated. The main purpose of this report is to present cytological data on several interspecific crosses with Ae. juvenalis which had not been studied previously. In all, 13 F1 hybrids involving Ae. juvenalis were studied, of which 12 were new combinations. These hybrid plants were established through the use of an embryo culture technique. The results of the study are presented in Table 1. These results support the earlier work of MCGINNlS (1956) who concluded that Ae. juvenalis has the Cu and D genomes. The data were inconclusive with respect to the third genome which KIHARA et al. have designated as the Mt. The cross between Ae. juvenalis and Ae. Aucheri bears speical mention. Multivalents were extremely prevalent, and associations of up to eleven were observed. Similarly the cross with Ae. crassa produced a high frequency of multivalents with associations of up to nine chromosomes. These crosses should be studied more intensively to determine the reason for the high multivalent formation. |