The effect of different Agropyron elongatum chromosomes on pairing in Agropyron – common wheat hybrids
Chromosome pairing at first meiotic metaphase was studied in hybrids between the common wheat cultivar Chinese Spring (CS) and an induced autotetraploid line derived from diploid Agropyron elongatum. The latter was found to carry genes for homoeologous pairing. To determine the chromosomal location of these and other genes that control pairing, disomic addition lines of A. elongatum in the cv. Chinese Spring were crossed with tetraploid cytotypes of A. elongatum, and pairing was then compared in the resulting hybrids and in hybrids between cv. Chinese Spring and tetraploid A. elongatum. The elongatum chromosomes were classified into those that suppress (6E), promote (5E, 3E, and possibly 1E), or have no effect on pairing (4E). The effect of chromosomes 2E and 7E was not studied. Chromosomes 5E and 3E differed in their effect on the degree and pattern of chromosome pairing. These findings are compared with the available data on the control of pairing in A. elongatum and in other Triticinae species.Key words: chromosome pairing, pairing promoter, Triticum, common wheat, Agropyron.