Coix is a grass crop domesticated as early as the Neolithic era.It is still widely cultivated for both highly nutritional food and medicinal use.However,the genetic study and breeding of this crop are hindered by the ...Coix is a grass crop domesticated as early as the Neolithic era.It is still widely cultivated for both highly nutritional food and medicinal use.However,the genetic study and breeding of this crop are hindered by the lack of a sequenced genome.Here,we report de novo sequencing and assembly of the 1619-Mb genome of Coix,and annotation of 75.39%repeats and 39629 protein-coding genes.Comparative genomics analysis showed that Coix is more closely related to sorghum than maize,but intriguingly only Coix and maize had a recent genome duplication event,which was not detected in sorghum.We further constructed a genetic map and mapped several important traits,especially the strength of hull.Selection of papery hull(thin:easy dehulling)from the stony hull(thick:difficult dehulling)in wild progenitors was a key step in Coix domestication.The papery hull makes seed easier to process and germinate.Anatomic and global transcriptome analysis revealed that the papery hull is a result of inhibition of cell division and wall biogenesis.We also successfully demonstrated that seed hull pressure resistance is controlled by two major quantitative trait loci(QTLs),which are associated with hull thickness and color,respectively.The two QTLs were further fine mapped within intervals of 250 kb and 146 kb,respectively.These resources provide a platform for evolutionary studies and will facilitate molecular breeding of this important crop.展开更多
基金supported by the National Natural Science Foundation of China(grant no.31971753,81703657)Key Project at Central Government Level:the Ability Establishment of Sustainable Use for Valuable Chinese Medicine Resources(2060302)+2 种基金the Fundamental Research Funds for Central Non-profit Scientific Institution of China(Y2017XM06,ZZ13-YQ-085)the Key Science and Technology Program of Biotechnology and Medicine of Sichuan Province(2018NZDZX0001)the National Basic Research Program of China(2014CB138705).
文摘Coix is a grass crop domesticated as early as the Neolithic era.It is still widely cultivated for both highly nutritional food and medicinal use.However,the genetic study and breeding of this crop are hindered by the lack of a sequenced genome.Here,we report de novo sequencing and assembly of the 1619-Mb genome of Coix,and annotation of 75.39%repeats and 39629 protein-coding genes.Comparative genomics analysis showed that Coix is more closely related to sorghum than maize,but intriguingly only Coix and maize had a recent genome duplication event,which was not detected in sorghum.We further constructed a genetic map and mapped several important traits,especially the strength of hull.Selection of papery hull(thin:easy dehulling)from the stony hull(thick:difficult dehulling)in wild progenitors was a key step in Coix domestication.The papery hull makes seed easier to process and germinate.Anatomic and global transcriptome analysis revealed that the papery hull is a result of inhibition of cell division and wall biogenesis.We also successfully demonstrated that seed hull pressure resistance is controlled by two major quantitative trait loci(QTLs),which are associated with hull thickness and color,respectively.The two QTLs were further fine mapped within intervals of 250 kb and 146 kb,respectively.These resources provide a platform for evolutionary studies and will facilitate molecular breeding of this important crop.
