Genotyping by sequencing of intergeneric Citrus + Poncirus somatic hybrids

Rootstocks are an important component for the adaptation of citrus to the increasing biotic and abiotic constraints resulting from global climate change. A strong complementarity exists between Citrus species, providing adaptation to abiotic stresses, and Poncirus trifoliata and its intergeneric hybrids, exhibiting resistances or tolerances to major diseases and pests. Therefore, symmetric somatic hybridization between these complementary diploid rootstocks appears to be an efficient way to develop new tetraploid rootstocks to tackle the new challenges of the citrus industry. A thorough characterization of nuclear and cytoplasmic genomes of plants regenerated after protoplast fusions was performed by genotyping by sequencing analysis. It revealed diploid cybrids and nuclear somatic hybrids. Mitochondrial genomes were generally inherited from the callus parent but homologous recombination events were observed for one combination. Chloroplasts displayed random mono parental inheritance. GBS revealed local chromosomal instability in all nuclear somatic hybrids and whole chromosome eliminations for two hybrids. However, at the whole genome level, a symmetrical addition of the nuclear genomes of both parent was mostly observed and all somatic hybrids displayed at least one haplotype of trifoliate orange all along the genome.Published in Dominique Dambier, Pascal Barantin, Gabriel Boulard, Gilles Costantino, Pierre Mournet, Aude Perdereau, Raphael Morillon and Patrick Ollitrault. Genomic instability in somatic hybridization between Poncirus and Citrus species aiming to create new rootstock . Agriculture MDPI.