摘要
【目的】对广东省二化螟Chilo suppressalis越冬地理种群基数监测、遗传多样性和系统发育进行调查和分析,为制定该虫有效的联防联控策略提供理论基础和参考。【方法】2017-2022年采取五点取样法对广东省各地区稻田进行二化螟采样,根据越冬代平均数量进行分级确定二化螟发生水平。利用PCR扩增广东省二化螟9个越冬地理种群线粒体基因COI和COII,利用MEGA 7和DNA Sequence Polymorphism 5.10.01软件分析二化螟越冬地理种群遗传多样性和遗传分化趋势,并构建系统发育树和单倍型网络图。【结果】2017-2022年广东省二化螟越冬地理种群基数很高,自2018年开始二化螟种群越冬虫量基本维持在7 500头/hm2,最严重地区可达18 408头/hm2。广东省二化螟9个越冬地理种群总计检测了132条COI和COII序列,COI片段长749 bp,有30个单倍型,54个位点存在多态性;COII片段长474 bp,有22个单倍型,29个多态位点。基于COI和COII序列的系统发育树显示,广东与江西二化螟地理种群聚合为一支;粤北南雄二化螟地理种群较其他地理种群相对独立,其他地理种群聚合为一支。珠三角地区、粤北地区、粤西地区、粤东地区和赣北地区二化螟地理种群单倍型多样性(Hd=0.800~0.909)和核苷酸多样性(Pi=0.0035~0.0102)都处于较高水平,粤西地区地理种群的遗传多样性最低。中性检验结果显示,基于COI序列,总种群Tajima’s D值为-1.043,Fu’Fs值为-5.023;基于COII序列,总种群Tajima’s D值为-1.907,Fu’Fs值为-10.468;COI+COII联合基因序列总种群Tajima’s D值为-1.313,Fu’Fs值为-31.67。基于COI和COII序列的总种群遗传分化指数Fst值分别为0.144和0.102,基因流Nm值分别为1.49和2.20;COI+COII联合基因序列的总种群遗传分化指数Fst值为0.229,基因流Nm值为0.84。【结论】广东省近年来二化螟越冬地理种群呈偏重甚至大发生趋势,且种群具有较高的单倍型多态性和遗传多样性;粤东越冬地理种群多态性较为丰富,粤西越冬地理种群多态性最低。本研究中广东省二化螟越冬种群间存在一定程度的遗传分化,有些地理种群已产生相对较大的分化,如南雄地理种群。广东省和江西省二化螟越冬地理种群具有较近的亲缘关系,除粤西地区外其他不同地理种群之间的遗传分化距离不明显,地理种群之间的遗传分化与分布之间相关性较小,种群间具有频繁的基因交流,种群未经历明显的扩张但处于稳定增长的趋势。
【Aim】Surveys and analyses of the overwintering geographic population size monitoring,genetic diversity and phylogeny of Chilo suppressalis in Guangdong Province,South China were conducted to provide theoretical foundations and references for formulating effective joint prevention and control strategies against this pest.【Methods】During 2017-2022,the five-point sampling method was adopted to collect C.suppressalis samples from paddy fields in various regions of Guangdong Province,and the occurrence level of C.suppressalis was determined based on the average number of overwintering generations.PCR was used to amplify mitochondrial genes COI and COII of nine overwintering geographic populations of C.suppressalis in Guangdong Province.The genetic diversity and genetic differentiation trends of the overwintering geographic populations of C.suppressalis were analyzed using MEGA 7 and DNA Sequence Polymorphism 5.10.01 software,and the phylogenetic tree and a haplotype network diagram were constructed.【Results】From 2017 to 2022,the geographical population base size of the overwintering C.suppressalis in Guangdong Province was very high.Since 2018,the number of overwintering C.suppressalis populations has basically remained at 7500 individuals/hm 2,and in the most severely affected areas,it could reach 18408 individuals/hm 2.A total of 132 COI and COII sequences were analyzed from nine overwintering geographic populations of C.suppressalis in Guangdong Province.The COI fragment was 749 bp in length,with 30 haplotypes and 54 polymorphic sites.The COII fragment was 474 bp in length,with 22 haplotypes and 29 polymorphic sites.Phylogenetic trees based on COI and COII sequences showed that the geographic populations of C.suppressalis in Guangdong and Jiangxi clustered together.The Nanxiong geographic population in northern Guangdong was relatively independent compared to other geographic populations which clustered together.The haplotype diversity(H d=0.800-0.909)and nucleotide diversity(P i=0.0035-0.0102)of the geographic populations of C.suppressalis in the Pearl River Delta Region,Northern Region of Guangdong,Western Region of Guangdong,Eastern Region of Guangdong,and Northern Region of Jiangxi were at high levels.The genetic diversity of geographic population in the Western Region of Guangdong was the lowest.Neutrality test results showed that the Tajima’s D value for the total population was-1.043 based on COI sequence and-1.907 based on COII sequence,while the Fu’s Fs values for the total population based on COI and COII sequences were-5.023 and-10.468,respectively.The Tajima’s D value and Fu’s Fs value for the total population were-1.313 and-31.67,respectively,based on combined COI+COII sequences.The genetic differentiation index F st values for the total population based on COI and COII sequences were 0.144 and 0.102,respectively,while the gene flow N m values were 1.49 and 2.20,respectively.The genetic differentiation index F st value and gene flow N m value for the total population based on combined COI+COII sequences were 0.229 and 0.84,respectively.【Conclusion】In recent years,the overwintering geographic populations of C.suppressalis in Guangdong Province have shown a trend of being predominant or even occurring in large numbers,and these populations have high levels of haplotypic polymorphism and genetic diversity.The overwintering geographic populations in eastern Guangdong are relatively rich in polymorphism,while those in western Guangdong have the lowest polymorphism.There is a certain degree of genetic differentiation among the overwintering populations of C.suppressalis in Guangdong Province,and some geographic populations have already undergone relatively large differentiation,such as the Nanxiong geographic population.The overwintering geographic populations of C.suppressalis in Guangdong Province and Jiangxi Province have close genetic relationships.Apart from the geographic populations from Western Region of Guangdong,the genetic differentiation between other different geographic populations is not significant.The genetic differentiation between geographic populations is weakly correlated with their distribution,and frequent gene exchange occurs among populations.The populations have not experienced significant expansion but are in a stable growth trend.
作者
袁龙宇
吴阳刚
钟文东
李燕芳
戴阳朔
张振飞
肖汉祥
YUAN Long-Yu;WU Yang-Gang;ZHONG Wen-Dong;LI Yan-Fang;DAI Yang-Shuo;ZHANG Zhen-Fei;XIAO Han-Xiang(Plant Protection Research Institute,Guangdong Academy of Agricultural Sciences,Guangzhou 510640,China;College of Plant Science&Technology of Huazhong Agricultural University,Wuhan 430070,China;Agricultural Pest Precaution and Management Center of Guangdong Province,Guangzhou 510500,China)
出处
《昆虫学报》
北大核心
2025年第5期667-678,共12页
Acta Entomologica Sinica
基金
广东省农业科学院创新基金项目(202201和202231)
广东省农业科学院“中青年学科带头人”培养项目(R2023PY-JG009)
广东省农业科学院人才培养计划青年研究员项目
广东省现代农业产业技术体系创新团队建设项目(2024CXTD05)。
