| Karyotypes of diploid Agropyron species By S. MATSUMURA and S. SAKAMOTO National Institute of Genetics, Misima On the strength of his previous crossing experiments, the senior author (MATSUMURA 1949) arrived at the conclusion that the genome which Agropyron glaucum (2n=42) and A. elongatum (2n=72) have in common with tetra-and hexaploid wheats is the B-genome. This view is contradictory to the hypothesis of MCFADDEN and SEARS (1946) who assume that A. triticeum is the carrier of the B-genome. It is well known that all chromosomes of B-genome have median or submedian constrictions. Our karyomorphological investigation of diploid A.elongatum and A. triticeum shows that the former has mostly median and submedian chromosomes, while all 7 chromosomes of the latter have subterminal centromeres. Our finding strongly supports the senior author's view and places MCFADDEN'S and SEARS' assumption in a very doubtful light. |