Chromosomal pairing at meiosis of F1 hybrid and backcross derivatives of Triticum aestivum × hexaploid Agropyron junceum

Abstract

The degree and pattern of chromosomal pairing at first meiotic metaphase were analyzed in several lines of hexaploid Agropyron junceum (2n = 42; genome J1J1J2J2EE), in the F1 hybrid between this species and common wheat, and in the backcrossed progeny of the hybrid to common wheat. Hexaploid A. junceum exhibited a strict bivalent pairing despite the relatedness of its genomes. Chromosomes of the J1 and J2 genomes of Agropyron paired in the F1 hybrid and in the backcross derivatives, in the presence of the Ph1 gene of common wheat. It was concluded that the corresponding chromosomes of the J1 and J2 genomes are distant homologues. It is assumed that the strict bivalent pairing in A. junceum is brought about by a gene system, similar to that found in several autotetraploid species.Key words: Agropyron junceum, Triticum aestivum, common wheat, wheat × Agropyron hybrids, chromosome pairing, bivalentization.