Study on Molecular Identification and Adaptation of Invasive Spodoptera frugiperda in Guiyang, Guizhou Province

Abstract

【Objective】Guizhou Province is an area for annual breeding of Spodoptera frugiperda. The use of molecular markers were used to identify the population biotypes of S. frugiperda in Guiyang, Guizhou, and its adaptability to Zea mays, Sorghum bicolor and Oryza sativa were studied, with a view to clarifying the biotype of S. frugiperda invading Guiyang and understanding the characteristics of its biotypes.【Method】A total of 32 S. frugiperda samples from three counties or cities in Guiyang, Guizhou were amplified, sequenced and analyzed for comparison by using CO Ⅰ and Tpi molecular marker methods, to determine the biotype of the population invading Guiyang, Guizhou. Additionally, the developmental duration, adult emergence rate and survival time of S. frugiperda larvae of various instars after feeding on three host plants (Zea mays, S. bicolor and O. sativa) were recorded to evaluate the adaptability of S. frugiperda to these three host plants.【Result】The results showed that among the 32 S. frugiperda samples, 93.75% belonged to the rice biotype while 6.25% belonged to the corn biotype based on the mitochondrial CO Ⅰ gene analysis. The sequence characteristics were highly consistent with the corresponding biotypes of S. frugiperda population. Meanwhile, the analysis of nuclear genome Tpi gene revealed that all samples showed the haplotype characteristics of the corn strain. The adaptability study indicated that the invasive S. frugiperda in Guiyang had the shortest larval period (13.22 d), longest adult survival time (16.42 d) and highest emergence rate (95.14 %) on Z. mays, followed by S. bicolor; while it had the longest larval period (16.59 d), shortest adult survival time (8.56 d) and lowest emergence rate (75.15 %) on O. sativa.【Conclusion】The biotypes of S. frugiperda invaded Guiyang, Guizhou Province were 93.75% rice type, 6.25% maize type using CO Ⅰ molecular marker, and 100% maize type using Tpi molecu lar marker. The life span of female S. frugiperda feeding on maize was significantly higher than those feeding on rice and S. bicolor. The results provide a basis for the prevention and control of S. frugiperda on S. bicolor.

Keywords

• spodoptera frugiperda
• guiyang
• biotype
• molecular marker
• host plant
• adaptability