Elucidating the origins and mechanisms of polyploidization requires tracing the evolutionary history of polyploid species,particularly those with complex origins.Agropyron cristatum,traditionally regarded as an autopo...Elucidating the origins and mechanisms of polyploidization requires tracing the evolutionary history of polyploid species,particularly those with complex origins.Agropyron cristatum,traditionally regarded as an autopolyploid,exhibits characteristics indicative of a segmental allopolyploid.Here,we used phylogenetic analysis based on a low-copy nuclear gene(i.e.,Pgk1),SLAF-seq,and plastome data from 20 diploid and 120 tetraploid Agropyron individuals to determine whether tetraploid A.cristatum arose from an allopolyploid or autopolyploid event.Phylogenetic analyses based on Pgk1 and SLAF-seq data identified two distinct A.cristatum lineages that corresponded to the two main Agropyron habitats in Central Asia–Europe and East Asia–Qinghai-Tibet Plateau.These findings,taken together with molecular dating and gene flow analyses,suggest that the East Asian tetraploid A.cristatum originated via both autopolyploidy from A.cristatum and hybridization between diploid A.cristatum and A.mongolicum,with each diploid cytotype acting as a maternal donor.Furthermore,the Central Asia–Europe tetraploid A.cristatum originated solely via autopolyploidy of diploid A.cristatum.Our findings also indicate that rapid diversification of Agropyron was likely driven by climate oscillations,geographic isolation,introgressive hybridization,and chloroplast capture.These findings challenge simplistic views of autopolyploids and underscore substantial potential for achieving high levels of genetic and adaptive diversity through recurrent hybridization and reticulate evolution.展开更多
利用简化基因组测序技术—特异性位点扩增片段测序技术(Specific-locus amplified fragment sequencing,SLAF-seq)对509份苹果属植物种质进行测序,获得586454个SLAF标签,其中多态性SLAF标签463612个;经过序列比对,根据完整度>0.94、...利用简化基因组测序技术—特异性位点扩增片段测序技术(Specific-locus amplified fragment sequencing,SLAF-seq)对509份苹果属植物种质进行测序,获得586454个SLAF标签,其中多态性SLAF标签463612个;经过序列比对,根据完整度>0.94、次要等位基因频率(MAF)>0.05,过滤筛选得到46460个多态性单核苷酸(SNP)位点;基于这些SNP位点构建苹果属植物不同种的系统发生树并分析主成分。结果表明,通过SLAF-seq技术能够在全基因组范围内快速开发高通量的SNP标记,并直接用于苹果属植物种质资源遗传多样性研究中。34种509份苹果属植物的多样性水平较高(He=0.318,I=0.488,Ae=1.520),在多于1份试材的种群中,变叶海棠的遗传多样性水平最高,中国苹果的遗传多样性水平最低。综合聚类分析和主成分分析结果表明,供试苹果属植物分为5个基本的类群,Ⅰ山荆子类群,Ⅱ苹果属植物野生种类群,Ⅲ苹果栽培品种类群,Ⅳ以中国苹果、八棱海棠、花红、楸子和海棠花为主的类群,Ⅴ新疆野苹果类群。野生种丽江山荆子、山楂海棠、陇东海棠、变叶海棠、花叶海棠、滇池海棠和沧江海棠聚类比较紧密,栽培种之间的亲缘关系相对较近,栽培品种与东方苹果和森林苹果等野生种聚在一起,新疆野苹果与中国原产苹果属栽培种的亲缘与起源演化关系有待于进一步考究。展开更多
基金funded by the following projects:the National Natural Science Foundation of China(Nos.31870360 and 32171603)Xining Science and Technology Major Project(2023-Z-13)+2 种基金Qinghai Provincial Science and Technology Major Project(2023-SF-A5)Youth Innovation Promotion Association(Chinese Academy of Sciences,Grant/Award Number:Y2023116)the Qinghai Provincial central guide local science and technology development funds project(2025ZY002).
文摘Elucidating the origins and mechanisms of polyploidization requires tracing the evolutionary history of polyploid species,particularly those with complex origins.Agropyron cristatum,traditionally regarded as an autopolyploid,exhibits characteristics indicative of a segmental allopolyploid.Here,we used phylogenetic analysis based on a low-copy nuclear gene(i.e.,Pgk1),SLAF-seq,and plastome data from 20 diploid and 120 tetraploid Agropyron individuals to determine whether tetraploid A.cristatum arose from an allopolyploid or autopolyploid event.Phylogenetic analyses based on Pgk1 and SLAF-seq data identified two distinct A.cristatum lineages that corresponded to the two main Agropyron habitats in Central Asia–Europe and East Asia–Qinghai-Tibet Plateau.These findings,taken together with molecular dating and gene flow analyses,suggest that the East Asian tetraploid A.cristatum originated via both autopolyploidy from A.cristatum and hybridization between diploid A.cristatum and A.mongolicum,with each diploid cytotype acting as a maternal donor.Furthermore,the Central Asia–Europe tetraploid A.cristatum originated solely via autopolyploidy of diploid A.cristatum.Our findings also indicate that rapid diversification of Agropyron was likely driven by climate oscillations,geographic isolation,introgressive hybridization,and chloroplast capture.These findings challenge simplistic views of autopolyploids and underscore substantial potential for achieving high levels of genetic and adaptive diversity through recurrent hybridization and reticulate evolution.
文摘利用简化基因组测序技术—特异性位点扩增片段测序技术(Specific-locus amplified fragment sequencing,SLAF-seq)对509份苹果属植物种质进行测序,获得586454个SLAF标签,其中多态性SLAF标签463612个;经过序列比对,根据完整度>0.94、次要等位基因频率(MAF)>0.05,过滤筛选得到46460个多态性单核苷酸(SNP)位点;基于这些SNP位点构建苹果属植物不同种的系统发生树并分析主成分。结果表明,通过SLAF-seq技术能够在全基因组范围内快速开发高通量的SNP标记,并直接用于苹果属植物种质资源遗传多样性研究中。34种509份苹果属植物的多样性水平较高(He=0.318,I=0.488,Ae=1.520),在多于1份试材的种群中,变叶海棠的遗传多样性水平最高,中国苹果的遗传多样性水平最低。综合聚类分析和主成分分析结果表明,供试苹果属植物分为5个基本的类群,Ⅰ山荆子类群,Ⅱ苹果属植物野生种类群,Ⅲ苹果栽培品种类群,Ⅳ以中国苹果、八棱海棠、花红、楸子和海棠花为主的类群,Ⅴ新疆野苹果类群。野生种丽江山荆子、山楂海棠、陇东海棠、变叶海棠、花叶海棠、滇池海棠和沧江海棠聚类比较紧密,栽培种之间的亲缘关系相对较近,栽培品种与东方苹果和森林苹果等野生种聚在一起,新疆野苹果与中国原产苹果属栽培种的亲缘与起源演化关系有待于进一步考究。
