Comparison of homoeologous chromosome pairing between hybrids of wheat genotypes Chinese Springph1band Kaixian-luohanmai with rye

Abstract

The ph-like genes in the Chinese common wheat landrace Kaixian-luohanmai (KL) induce homoeologous pairing in hybrids with alien species. In the present study, meiotic phenotypic differences on homoeologous chromosome pairing at metaphase I between hybrids of wheat genotypes Chinese Spring ph1b (CSph1b) and KL with rye were studied by genomic in situ hybridization (GISH). The frequency of wheat–wheat associations was higher in CSph1b × rye than in KL × rye. However, frequencies of wheat–rye and rye–rye associations were higher in KL × rye than in CSph1b × rye. These differences may be the result of different mechanisms of control between the ph-like gene(s) controlling homoeologous chromosome pairing in KL and CSph1b. Wheat–wheat associations were much more frequent than wheat–rye pairing in both hybriods. This may be caused by lower overall affinity, or homoeology, between wheat and rye chromosomes than between wheat chromosomes.