Study of the long-distance migration of small brown planthoppers Laodelphax striatellus in China using next-generation sequencing.

BACKGROUND: The small brown planthopper (Laodelphax striatellus) is a widespread insect pest of rice in East Asia. Previous studies have shown the long-distance migrations undertaken by L. striatellus, but have not provided molecular evidence to support this. RESULTS: Long-distance immigration has occurred in the north-east coastal rice-growing region of China. Using the specific-locus amplified fragment sequencing technique, sequence data for 2.7 Gb of an abruptly increased population and 13 L. striatellus local populations from a range of regions in China that have serious rice stripe disease were obtained. A total of 2572 single nucleotide polymorphisms (SNPs) and 37 indels were detected, and the genotypes of many polymorphism sites were heterozygous in every sample, which indicated that there were rich genetic differences among the populations, and that the migration of insect pests accelerated the gene flow and increased the heterozygosity of L. striatellus populations. The genetic distance and the polymorphism markers among different populations showed that the abruptly increased population in Liaoning Province is close to several populations from Jiangsu Province and Shandong Province. CONCLUSION: The vector that caused rice stripe disease in the north-east of China was an immigrant population; however, the population may be formed from several groups from different areas, such as Jiangsu and Shandong provinces.