The genus Populus comprises a complex amalgam of ancient and modern species that has become a prime model for evolutionary and taxonomic studies. Here we sequenced the genomes of 10 species from five sections of the genus Populus , identified 71 million genomic variations, and observed new correlations between the single-nucleotide polymorphism–structural variation (SNP–SV) density and indel–SV density to complement the SNP–indel density correlation reported in mammals. Disease resistance genes (R genes) with heterozygous loss-of-function (LOF) were significantly enriched in the 10 species, which increased the diversity of poplar R genes during evolution. Heterozygous LOF mutations in the self-incompatibility genes were closely related to the self-fertilization of poplar, suggestive of genomic control of self-fertilization in dioecious plants. The phylogenetic genome-wide SNPs tree also showed possible ancient hybridization among species in sections Tacamahaca, Aigeiros, and Leucoides. The pangenome resource also provided information for poplar genetics and breeding.

IGF-1R plays a critical role in many physiological activities, such as development, growth, metabolism, and reproduction. Identification of genetic markers in the IGF-1R gene significantly associated with important growth traits of Odontobutis potamophila may accelerate genetic improvement. In this study, we characterized the cDNA sequence of the IGF-1R gene of O. potamophila, and our data revealed that IGF-1R contained an open reading frame of 1650 bp, encoding a polypeptide of 549 amino acids (aa). Quantitative real-time polymerase chain reaction demonstrated that IGF-1R was ubiquitously expressed in all tested tissues, and the most predominant expression of IGF-1R was detected in gonad. Moreover, IGF-1R was expressed at different developmental stages from embryo to larva, and its highest expression level was found at the morula stage. In addition, we identified three single nucleotide polymorphisms (SNPs; 1777T>C, 1704G>A, and 1208G>A) within IGF-1R locus and found that one SNP (1208G>A) was significantly associated with important growth traits of O. potamophila. Results showed that the overall length, body length, trunk width, caudal peduncle length, body weight, and body width in fish with AG genotype were significantly greater compared with those with GG genotype (P < 0.05). However, the other two SNPs (1777T>C and 1704G>A) did not show significant associations with any growth traits. Therefore, SNPs within the IGF-1R locus could be used as a selection criterion to improve growth traits of O. potamophila.

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