摘要：Abstract In Rosaceae species, two gametophytic self-incompatibility (GSI) mechanisms are described, the Prunus self-recognition system and the Maleae ( Malus/Pyrus/Sorbus ) non-self- recognition system. In both systems the pistil component is a S-RNase gene, but from two distinct phylogenetic lineages. The pollen component, always a F-box gene(s), in the case of Prunus is a single gene, and in Maleae there are multiple genes. Previously, the Rosa S -locus was mapped on chromosome 3, and three putative S-RNase genes were identified in the R. chinensis ‘Old Blush’ genome. Here, we show that these genes do not belong to the S -locus region. Using R. chinensis and R. multiflora genomes and a phylogenetic approach, we identified the S-RNase gene, that belongs to the Prunus S -lineage. Expression patterns support this gene as being the S -pistil. This gene is here also identified in R. moschata , R. arvensis , and R. minutifolia low coverage genomes, allowing the identification of positively selected amino acid sites, and thus, further supporting this gene as the S-RNase . Furthermore, genotype–phenotype association experiments also support this gene as the S-RNase . For the S -pollen GSI component we find evidence for multiple F-box genes, that show the expected expression pattern, and evidence for diversifying selection at the F-box genes within an S -haplotype. Thus, Rosa has a non-self-recognition system, like in Maleae species, despite the S -pistil gene belonging to the Prunus S-RNase lineage. These findings are discussed in the context of the Rosaceae GSI evolution. Knowledge on the Rosa S -locus has practical implications since genes controlling floral and other ornamental traits are in linkage disequilibrium with the S -locus.
其他摘要：Abstract In Rosaceae species, two gametophytic self-incompatibility (GSI) mechanisms are described, the Prunus self-recognition system and the Maleae ( Malus/Pyrus/Sorbus ) non-self- recognition system. In both systems the pistil component is a S-RNase gene, but from two distinct phylogenetic lineages. The pollen component, always a F-box gene(s), in the case of Prunus is a single gene, and in Maleae there are multiple genes. Previously, the Rosa S -locus was mapped on chromosome 3, and three putative S-RNase genes were identified in the R. chinensis ‘Old Blush’ genome. Here, we show that these genes do not belong to the S -locus region. Using R. chinensis and R. multiflora genomes and a phylogenetic approach, we identified the S-RNase gene, that belongs to the Prunus S -lineage. Expression patterns support this gene as being the S -pistil. This gene is here also identified in R. moschata , R. arvensis , and R. minutifolia low coverage genomes, allowing the identification of positively selected amino acid sites, and thus, further supporting this gene as the S-RNase . Furthermore, genotype–phenotype association experiments also support this gene as the S-RNase . For the S -pollen GSI component we find evidence for multiple F-box genes, that show the expected expression pattern, and evidence for diversifying selection at the F-box genes within an S -haplotype. Thus, Rosa has a non-self-recognition system, like in Maleae species, despite the S -pistil gene belonging to the Prunus S-RNase lineage. These findings are discussed in the context of the Rosaceae GSI evolution. Knowledge on the Rosa S -locus has practical implications since genes controlling floral and other ornamental traits are in linkage disequilibrium with the S -locus.
