Fine-mapping Of The Dwarf Genein Yansizhi Of Foxtail Millet

Foxtail millet belongs to a single cotyledon gramineous plants,scientific name is Setaria italica,its grain after peeling is commonly known as the "millet",is one of the major food crops in China.Due to its rich grain nutrition,and the content of dietary fiber and essential trace elements content rich compared to other food crops,as a result,millet is considered to be one of the health food to human life.Along with the rapid development of molecular biology and crop molecular genetic breeding,DNA molecular marker tags gradually replace the traditional form of genes and people's understanding also gradually developes from phenomenon to essence.In the 1960's,the discovery and utilization of sd1 gene of rice promotes the "green revolution" of gramineous plants,the main crops such as corn,wheat,sorghum,rape dwarf genes also have been found,then the gramineae plant' productivity ability also have improved.As a result,proper plant height for lodging resistance,photosynthetic efficiency and yield of crops has a very important role.Millet,however,the drought resistance and barren resistance varieties,haven't developed with high lodging resistance and yield of high quality varieties,and in the existing varieties of foxtail millet,plant high,stalk fragile,lodging resistance and disease resistance ability is poorer,these factors influenced the yield of millet.Therefore,mining,short in foxtail millet or semi-dwarf gene modified corn plant type breeding practice has a very important role.The experiment on plant height has obvious differences,short of materials delay four straight as female parent,the high stalk material No.1 as the male parent do,and get the F1 generation of hybrid,F1 all characterized by high stem,after planting in F2 generation after planting the characteristics of high,short separation,and the separation of high stem and stem ratio of 3:1,conform to the laws of Mendelian inheritance,therefore,the stem is quality traits of the group can be determined,the gene for single recessive gene.Test procedures are as follows:1.Use uniform distribution on millet 9 chromosomes of 383 pairs of SSR primers tags,for these tags with BSA recessive plant mixing pool method to filter,first find the P17 Xprimers with four straight dwarf has chain relationship,this primer marker in foxtail millet on chromosome 5 short arm,physical distance to 43358641 bp;In P17 X primers of upstream and downstream and 15 pairs of SSR primers selected tag,for initial positioning and fine positioning.Through exchange of F2 population mid-low individual plant selection,determine the groups of dwarf recessive gene on chromosome 5 in foxtail millet markers between P17 X B223,the physical distance between the two chain tag is about 2.4 Mb,and basically complete the group mid-low recessive gene positioning at the beginning of study.2.The groups of dwarf recessive gene is fine.By millet genome physical mapping,DNAMAN software will millet of 5 chromosome P17X-B223 primer marker 2.4 Mbp DNA Sequence between shear down,use SSRhunter software,Primer3.0 software designed 131 pairs of SSR primer marker,find 4 pairs of primers were markers showed polymorphism between the parents in the community,the four pairs of primers tag YGY5001,YGY5045 respectively,YGY5082,YGY5012.Using the four polymorphisms primer marker screening of this group of exchange of strains,genetic fine positioning,will be located in dwarfing genes YGY5045 and YGY5082 between two primer marker,the physical distance between the two SSR markers to 254 kb.3.The pilot study for four straight stem plants sprayed with gibberellin solution,plant increased significantly,that four straight dwarf is sensitive to ga3,suggesting the dwarf might be related to ga3 synthesis gene mutation.By searching through the BAC library to find the interval candidate genes during YGY5045-YGY5082,have found 48 genes,analysing the 48 candidate genes by bioinformatics,and finding no homologous genes associated with gibberellin.Thus speculate that the dwarf gene may be a new and gibberellin or other genes associated with plant height control.This research for the further understanding of millet varieties of four straight dwarf and mid-low mechanism laid a foundation.