基于单基因和联合基因的新疆黑条小车蝗种群遗传多样性分析

Analysis on population genetic diversity of Oedaleus decorus decorus in Xinjiang based on monogene and multi⁃loci

黑条小车蝗[Oedaleus decorus decorus (Germar)]是新疆温性荒漠草原最为重要的蝗害之一,目前关于新疆该蝗种群的遗传多样性和亲缘关系尚不明确。测定了新疆黑条小车蝗14个地理种群194条序列的线粒体COI和ND5基因,通过单基因和联合基因分析比较新疆该蝗的遗传多样性和遗传分化情况,并基于可信度高的联合基因探讨新疆该蝗种群可能的扩散路径。黑条小车蝗14个地理种群的COI和ND5联合基因均表现出高遗传多样性(Hd为0.904 8~1.000 0,Pi为0.010 0~0.341 5),且各种群间遗传分化较大,基因交流不充分(Fst为0.385 1,Nm为0.40)。种群间的遗传差异来源于种群内部(80.03%),并且地理距离可能不是影响种群间遗传距离的主要因素。综合遗传多样性分析,单倍型网络图和系统发育树结果显示联合基因较于单基因可信度更高。新疆黑条小车蝗遗传分化较高的种群可能主要由地形地貌所致,遗传分化较低的种群可能受西北季风影响;新疆黑条小车蝗种群的早期建立种可能来源于伊犁地区,一支经天山山脉扩散至博乐、乌市及哈密地区,另一支由塔城地区经准噶尔盆地扩散至富蕴县。

Oedaleus decorus decorus is one of the most important locust pests in the temperate desert grasslands of Xinjiang.Currently,the genetic diversity and affinities of the Xinjiang populations of this locust are still unclear.In this study,we determined the mitochondrial COI and ND5 genes in 194 individuals from 14 geographic populations of O.de⁃corus decorus in Xinjiang,compared the genetic diversity and genetic differentiation of this locust by monogene and multi⁃loci analysis,and explored the possible dispersal pathways of the Xinjiang populations of this locust based on the highly plausible multi⁃loci.The multi⁃loci of COI and ND5 in 14 populations of O.decorus decorus showed high genetic diversi⁃ty(Hd 0.9048-1.0000,Pi 0.0100-0.3415)and high genetic differentiation among populations with insufficient gene exchange(Fst 0.3851,Nm 0.40).Genetic differences among populations originated from within populations(80.03%),and geographical distance may not be the main factor affecting genetic distance among populations.The com⁃prehensive analysis of the genetic diversity,haplotype network diagram and phylogenetic tree results showed that multi⁃lo⁃ci were more plausible than monogene.The higher genetic differentiation of O.decorus decorus populations in Xinjiang may be mainly due to topography and geomorphology,while the lower genetic differentiation of the populations may be af⁃fected by the northwest monsoon.The early established species of O.decorus decorus populations in Xinjiang may have originated from the Ili area,with one spreading to Bole,Urumqi,and Hami areas via the Tianshan Mountains,and the other spreading from the Tacheng area via the Junggar Basin to Fumun County.