入侵贵州贵阳草地贪夜蛾的分子鉴定及适应性研究

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

【目的】贵州省为草地贪夜蛾(Spodoptera frugiperda)的周年繁殖区,采用分子标记鉴定贵州贵阳草地贪夜蛾的种群生物型,并对其在玉米、高粱、水稻上的适应性进行研究,以明确入侵贵州贵阳的草地贪夜蛾的种群生物型并了解其特性。【方法】采用COⅠ和Tpi两种分子标记,对贵州贵阳3个县市共32个草地贪夜蛾样本进行PCR扩增、测序和比对分析,明确入侵贵州贵阳的种群生物型。记录草地贪夜蛾各龄期幼虫取食3种寄主植物(玉米、高粱、水稻)后的发育历期、成虫羽化率和存活时长,评估草地贪夜蛾对3种寄主植物的适应性。【结果】基于线粒体COⅠ基因分析结果显示,32个草地贪夜蛾样本中,93.75%为水稻型、6.25%为玉米型,且其序列特征与相应生物型的草地贪夜蛾种群具有较高的一致性;而基于核基因组Tpi基因分析的结果表明,32个样本的单倍型特点均表现为玉米型。适应性研究结果显示,入侵贵阳的草地贪夜蛾在玉米上的幼虫期最短(13.22 d)、成虫存活时间最长(16.42 d)、羽化率最高(95.14%),在高粱上次之,在水稻上的幼虫期最长(16.59 d)、成虫存活时间最短(8.56 d)、羽化率最低(75.15%)。【结论】利用COⅠ分子标记方法鉴定入侵贵州贵阳的草地贪夜蛾种群生物型时,93.75%为水稻型、6.25%为玉米型,而利用Tpi分子标记的结果为100%玉米型。以玉米为食的雌性草地贪夜蛾寿命明显高于以水稻、高粱为食的雌性草地贪夜蛾。研究结果有助于分析入侵贵州省的草地贪夜蛾来源,可为高粱的草地贪夜蛾防控提供一定的基础。

【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.