Fate Of Aegilops Speltoides-Derived, Repetitive Dna Sequences In Diploid Aegilops Species, Wheat-Aegilops Amphiploids And Derived Chromosome Addition Lines

The present study reports the cloning and characterization of an Aegilops speltoides-derived subtelomeric repeat, designated as pSp1B16. Clone pSp1B16 has 98% sequence homology with the previously isolated Ae. speltoides repeat Spelt1. The distribution of pSp1B16 and another Ae. speltoides repeat, pGc1R1, was analyzed in diploid Aegilops species, tetra-and hexaploid wheats, wheat-Aegilops amphiploids and derived chromosome addition lines by fluorescence in situ hybridization (FISH). Clones pSp1B16 and pGc1R1 revealed FISH sites in Ae. speltoides, Ae. sharonensis and Triticum timopheevii, whereas additional pGc1R1 FISH sites were observed in Ae. longissima and Ae. caudata. The pSp1B16 and pGc1R1 FISH patterns of the Aegilops chromosomes in the wheat-Aegilops amphiploids and chromosome addition lines are similar to those present in the Aegilops parent accession. We did not observe any evidence of pSp1B16 and pGc1R1 sequence elimination, which is in contrast to previous studies using similar hybrids and repeats. The presented data suggest that the genomic changes in synthetic amphiploids observed in previous studies might be caused by homoeologous recombination, which was suppressed in the amphiploid analyzed in this study. Copyright (C) 2010 S. Karger AG, Basel