关键词: 菜豆象, SNP标记, 重测序, 种群溯源, 种群结构

Abstract: 【Aim】Based on the resequencing data from different populations of Acanthoscelides obtectus and screening of the single nucleotide polymorphism (SNP)  molecular markers, we analyzed the genetic diversity and population structure among these populations, and screened the population-specific SNP loci for origin tracing of the sampled populations, to be used for traceability detection of the intercepted populations at ports.【Methods】A total of 104 adult A. obtectus samples from 19 populations (10 from China and 9 from abroad) were subjected to whole-genome resequencing. The SNP loci with the highest population differentiation index (F_st) were selected as the SNP loci of population-specific variation (100% specific SNPs). Amplification primers were designed on both sides of the loci for SNP locus amplification.【Results】A total of 5 264 357 high-quality SNP loci were identified from the 104 adult samples of A. obtectus. The populations were clustered into four major groups: the Germany group, the Africa-Chile group (Ethiopia, Burundi, Cameroon, Congo, Uganda, Angola and Chile), the Guizhou group in China, and the Yunnan group in China. Gene flow analysis suggested a single gene migration event among 15 populations, from the Cameroon population to the Congo population. The Yunnan and Guizhou groups in China exhibited relatively independent genetic backgrounds, showing far genetic distance from the Africa-Chile and Germany groups. Ten population-specific SNP loci for origin tracing were successfully established for the populations from Guizhou in China, Yunnan in China, Ethiopia, Burundi, Cameroon, Congo, Uganda, Angola, Germany and Chile by screening the high-quality SNP loci for A. obtectus population tracing, and the detection primers could effectively and accurately identify the genotypes of these ten target geographic populations.【Conclusion】 The ten population-specific SNP molecular markers of A. obtectus developed in this study enable the accurate identification of genotypes in target populations, providing a simple, practical and straightforward method for tracing population origins in quarantine inspections and pest control.

Key words: Acanthoscelides obtectus, SNP marker, resequencing, population origin tracing, population structure