Doubled haploid cells, embryos and plants

Abstract

Methods for producing homozygous plants, seeds, and plant cells are provided. Methods of forming haploid tissue and then doubling the chromosomes to form doubled haploid cells are provided. Also provided are methods of transformation.

1 . A method of making a doubled haploid maize plant comprising: 
 a) contacting a maize haploid embryo with a chromosome doubling agent to produce a doubled haploid embryo;    b) generating a doubled haploid maize plant from said doubled haploid embryo.    
     
     
         2 . The method of  claim 1  wherein said embryo is produced by crossing a female plant with a male inducer line.  
     
     
         3 . The method of  claim 2  wherein the inducer line contains a scorable marker gene.  
     
     
         4 . The method of  claim 3  wherein said marker gene is selected from the group consisting of an anthocyanin gene, R-nj, GFP, and lec1 promoter driving CRC.  
     
     
         5 . The method of  claim 1  wherein said doubling agent is selected from the group consisting of colchicines, nitrous oxide, and pronamide.  
     
     
         6 . The method of  claim 1  further comprising transforming said haploid embryo before contacting said haploid embryo with said doubling agent.  
     
     
         7 . A method of making a doubled haploid maize plant comprising: 
 a) generating callus from a maize haploid embryo    b) contacting said callus with a chromosome doubling agent;    c) generating a doubled haploid somatic embryo from said callus;    d) generating a doubled haploid maize plant from said doubled haploid somatic embryo.    
     
     
         8 . The method of  claim 7  wherein said immature embryo is produced by crossing a female plant with a male inducer line.  
     
     
         9 . The method of  claim 8  wherein the inducer line contains a scorable marker gene.  
     
     
         10 . The method of  claim 9  wherein said marker gene is selected from the group consisting of an anthocyanin gene, R-nj, GFP, and lec1 promoter driving CRC.  
     
     
         11 . The method of  claim 7  wherein said doubling agent is selected from the group consisting of colchicine, nitrous oxide, and pronamide.  
     
     
         12 . The method of  claim 7  further comprising transforming said callus before contacting said callus with said doubling agent.  
     
     
         13 . A method of making a doubled haploid maize cell comprising: contacting a maize haploid embryo with a chromosome doubling agent to produce a doubled haploid cell.  
     
     
         14 . The method of  claim 13  wherein said embryo is produced by crossing a female plant with a male inducer line.  
     
     
         15 . The method of  claim 14  wherein the inducer line contains a scorable marker gene.  
     
     
         16 . The method of  claim 15  wherein said marker gene is selected from the group consisting of an anthocyanin gene, R-nj, GFP, and lec1 promoter driving CRC.  
     
     
         17 . The method of  claim 13  wherein said doubling agent is selected from the group consisting of colchicine, nitrous oxide, and pronamide.  
     
     
         18 . A method of making a doubled haploid maize embryo comprising: 
 contacting a maize haploid embryo with a chromosome doubling agent to produce a doubled haploid embryo.    
     
     
         19 . The method of  claim 18  wherein said embryo is produced by crossing a female plant with a male inducer line.  
     
     
         20 . The method of  claim 19  wherein the inducer line contains a scorable marker gene.  
     
     
         21 . The method of  claim 20  wherein said marker gene is selected from the group consisting of an anthocyanin gene, R-nj, GFP, and lec1 promoter driving CRC.  
     
     
         22 . The method of  claim 18  wherein said doubling agent is selected from the group consisting of colchicine, nitrous oxide, and pronamide.