Genome-Wide Identification and Evolutionary Analysis of Genes From .

is an important food crop that is mainly cultivated in subtropical regions of the world. is frequently infected by various pathogens during its lifespan, which results in a substantial economic loss in terms of yield and quality. The disease resistance gene ( gene) profile of is largely unknown, which has greatly hampered molecular study of disease resistance in this species. () genes are the largest group of plant genes, and they play important roles in plant defense responses to various pathogens. In this study, 167 genes were identified from the genome. Subsequently, one gene was assigned to the () () subclass and the other 166 genes to the () () subclass. None of the () () genes were detected in the genome. Among them, 124 genes are located in 25 multigene clusters and 43 genes are singletons. Tandem duplication serves as the major force for the cluster arrangement of genes. Segmental duplication was detected for 18 genes, although no whole-genome duplication has been documented for the species. Phylogenetic analysis revealed that genes share 15 ancestral lineages with genes. The gene number increased by more than a factor of 10 during evolution. A conservatively evolved ancestral lineage was identified from , which is orthologs to the gene. Transcriptome analysis for four different tissues of revealed a low expression of most genes, with the tuber and leaf displaying a relatively high gene expression than the stem and flower. Overall, this study provides a complete set of genes for , which may serve as a fundamental resource for mining functional genes against various pathogens.