Establish Of Rapid Propagation System And Transcriptome Analysis Of Panicle Development In Echinochloa Damo Of Different Ploidy

Echinochloa damo,the C₄ plant and a Japanese millet variety of Echinochloa,with high photosynthetic efficiency,strong resistance,wide adaptability,and non-shattering and other characteristics,which is an excellent plant resource.It is difficult to use polyploidization to overcome the problems of non-affinity and non-pregnancy of hybrids in distant hybridization,because of the difficult to expand reproduction of autopolyploid Echinochloa damo.In the present study,we will useautopolyploid Echinochloa damo to established rapid propagating system of the tissue culture response,and the diploid Echinochloa damo as control.Furthermore,we will investigatethe gene expressionpatterns of the anther in meiosis stagebetween autopolyploid Echinochloa damo and diploid by using RNA-seq.The main results are as follows:1.Establishment of a rapid reproductive system of Echinochloa damo.We found that the mature embryos produced the highest induction frequency and better quality of calli on N₆+3.0mg/L 2,4-D?pH5.4⁵.8?,which added organic substance.The favorable shoot inducing medium was 1/2MS+2.0mg/L 6-BA+0.5mg/L NAA?pH5.4⁵.8?and the differentiation frequency was 88.33%.We found MS+4 mg/L6-BA was the optimum concentration for the propagation of adventitious buds.Autopolyploid Echinochloa damo wasnot suitable for a rapid propagating system.2.Agronomic traits in autopolyploid of Echinochloa damo.Lots of changes were found in autopolyploid Echinochloa damocomparedto the diploid Echinochloa damo,including greener leaf color,wider leaf,and coarserstem,more dwarf plant height,reduced tiller number,decreased seed setting rate etc.These features could be the primary screening index for polyploidy induction.Microscopic observation of blade surfaceshowed that the stomatal density was decreased,and the stomatal size of the plants was increasedcomprised with the controls,In addition the pollen fertility of autoteraploid Echinochloa damowas significant lower thandiploid.3.Transcriptome analysis of the autotetraploid Echinochloa damo.We use RNA-seq tocompare the gene expression patternsof the meiosis stage of the autotetraploid Echinochloa damo with the dipoid counterpart,and results showed that 1092and 1409 genes showed up-and down-regulation.The differentially expressed genes were enriched inregulation of flower development,reciprocal meiotic recombination,sister chromatid cohesion of molecular function category of these features annotated genes by Gene Ontology enrichment analysis.By pathway enrichment analysis,some down-regulation genes were associated with photosynthesis,plant hormone signal transduction and starch and sucrose metabolism.The abnormal expression of these genes mayaffect the meiosis and the developmental of pollen,which result in the low pollen fertility in autoteraploid Echinochloa damo.Six differentially expressed genes were selected in for verification by using q RT-PCRtechnology,and results conform to RNA-seq.Itshows that the transcriptome resultswere reliable.