Methods for rapidly transforming monocots

Abstract

The present invention provides methods for transforming monocot plants via a simple and rapid protocol, to obtain regenerated plants capable of being planted to soil in as little as 4-8 weeks. Associated cell culture media and growth conditions are also provided, as well as plants and plant parts obtained by the method. Further, a method for screening recalcitrant plant genotypes for transformability by the methods of the present invention is also provided. Further, a system for expanding priority development window for producing transgenic plants by the methods of the present invention is also provided.

1 .- 38  (canceled) 
     
     
         39 . A system for expanding a priority development window for producing transgenic plants, comprising:
 a) selecting a candidate DNA segment of interest for producing a transgenic plant based at least in part on data collected in a first field test;   b) preparing a transgenic monocot plant comprising the candidate DNA segment by the method of claim  1 ; and   c) assaying the transgenic plant for a desired phenotype and/or genotype in at least a second field test conducted in a growing season subsequent to that in which the first field test is conducted.   
     
     
         40 . The method of  claim 39 , wherein one or both of the first field test or second field test are conducted in the mid-west United States. 
     
     
         41 . The method of  claim 39 , wherein assaying the transgenic plant comprises measuring agronomic performance. 
     
     
         42 . The method of  claim 39 , wherein the second field test is a hybrid yield test. 
     
     
         43 . The method of  claim 39 , wherein the second field test is performed two growing seasons after the first field test. 
     
     
         44 . A method for screening cells of a crop plant line for transformability, comprising
 a) culturing crop plant explants on a growth medium that supports production of shoot primordia within about 1-2 weeks;   b) culturing the shoot primordia under conditions that support shoot elongation for at least about a further week in the dark to obtain growing shoot tissue and/or plantlets;   c) culturing the tissue or plantlets of step (b) on a plant growth medium for at least about a further week to obtain shoot buds and/or plants;   
       wherein the transformability of the cells is measured by the ability of shoot primordia to produce shoot buds and/or plants following step (c). 
     
     
         45 . The method of  claim 44 , wherein the growth medium of step (a) comprises an effective ratio of cytokinin and auxin to support production of shoot primordia. 
     
     
         46 . The method of  claim 45 , wherein the ratio of cytokinin to auxin in the growth medium of step (a) is from about 0.005 to about 0.03 (w/w). 
     
     
         47 . The method of  claim 46 , wherein the growth medium of step (a) is Lynx 1947. 
     
     
         48 . The method of  claim 44 , wherein the growth medium of step (b) comprises cytokinin. 
     
     
         49 . The method of  claim 48 , wherein the growth medium of step (b) is Lynx 2424.