Identification of chromosome loss and rearrangement in potato and eggplant somatic hybrids by rDNA and telomere repeats

Abstract

<p id="C3">Somatic hybridization is an important way to create new germplasm. Somatic hybrids produced plenty of genetic variation during protoplast regeneration. In this study, to analyze the chromosome composition and variation of potato and eggplant somatic hybrids, rDNAs and telomeric repeats were used as probes for FISH (fluorescence in situ hybridization), combined with GISH (Genomic in situ hybridization). The results showed that rearranged chromosomes and dicentric chromosomes existed in somatic hybrids, and the parts of the rearranged chromosomes was derived from the end-to-end fusion of potato and eggplant chromosomes 2. One centromere of the rearranged dicentric chromosomes was derived from potato and the other was from eggplant. Eggplant 5S rDNA sites were lost in somatic hybrids to homogenize the rDNA of somatic hybrids. The results of this study indicated that the chromosomes were unstable during the somatic hybridization of potato and eggplant, which can easily cause dicentric and chromosomal rearrangements in somatic hybrids. The chromosomes of somatic hybrids tended to be stable through various ways such as chromosome rearrangement, dicentric and rDNA homogenization.