Non-destructive assessment of corn rootworm damage

Abstract

The present embodiments generally relate to methods of non-destructively imaging plant root damage by insect root herbivores and evaluating the efficacy of insecticidal materials associated with the roots of plants against the insect root herbivores, useful for automated high throughput bioassays.

What is claimed is: 
     
         1 . A method of non-destructively determining the resistance of candidate plant roots to insect herbivory, comprising subjecting root tissue of the candidate plant comprising at least one insecticidal material associated with said root tissue to at least one insect root herbivore, obtaining a non-destructive image of roots of said candidate plant, wherein the candidate plant roots are substantially embedded in the soil, and determining the resistance of the candidate plant roots to insect herbivory based on injury to the root tissue. 
     
     
         2 . The method of  claim 1 , comprising obtaining the non-destructive image using X-ray computed tomography. 
     
     
         3 . The method of  claim 1 , comprising obtaining the root images of at least two candidate plants simultaneously or sequentially. 
     
     
         4 . The method of  claim 1 , wherein the injury to the root tissue results in a determination of a root nodal injury score. 
     
     
         5 . The method of  claim 1 , comprising determining the injury to the root tissue by measuring root volume, root length, root growth rate, root branching morphology, or root depth distribution. 
     
     
         6 . The method of  claim 1 , comprising generating the root nodal injury score by a processor, wherein said processor receives a digital image and generates a root nodal injury score. 
     
     
         7 . The method of  claim 1 , wherein the insect root herbivore is a  Diabrotica  species. 
     
     
         8 . The method of  claim 7 , wherein said  Diabrotica  species is selected from the group consisting of  Diabrotica virgifera, Diabrotica undecimpunctata howardi , and  Diabrotica barberi.    
     
     
         9 . The method of  claim 1 , wherein the insecticidal material is selected from the group consisting of an insecticidal protein, a double-stranded RNA, a chemical insecticide, and a biological insecticide. 
     
     
         10 . A method of non-destructively assaying the efficacy of an insecticidal material to insect root herbivory, comprising subjecting root tissue of a candidate plant comprising at least one insecticidal material associated with said root tissue to at least one insect root herbivore, presenting the candidate plant to a non-destructive imaging apparatus, obtaining a non-destructive image of roots of said candidate plant, and generating a root nodal injury score. 
     
     
         11 . The method of  claim 10 , comprising presenting the candidate plant to the imaging apparatus in a pot. 
     
     
         12 . The method of  claim 10 , comprising presenting the candidate plant to the imaging apparatus by an automated movement system. 
     
     
         13 . The method of  claim 12 , wherein the automated movement system comprises a transportation belt. 
     
     
         14 . The method of  claim 10 , wherein the imaging apparatus comprises an X-ray imager. 
     
     
         15 . The method of  claim 10 , wherein the non-destructive image is obtained using X-ray computed tomography. 
     
     
         16 . The method of  claim 10 , comprising obtaining the root images of at least two candidate plants simultaneously or sequentially. 
     
     
         17 . The method of  claim 10 , comprising manually generating the root nodal injury score using the non-destructive image. 
     
     
         18 . The method of  claim 10 , comprising generating the root nodal injury score by a processor, wherein said processor receives a digital image and generates a root nodal injury score. 
     
     
         19 . The method of  claim 10 , wherein the insect root herbivore is a  Diabrotica  species. 
     
     
         20 . The method of  claim 19 , wherein said  Diabrotica  species is selected from the group consisting of  Diabrotica virgifera, Diabrotica undecimpunctata howardi , and  Diabrotica barberi.    
     
     
         21 . The method of  claim 10 , wherein the insecticidal material is selected from the group consisting of an insecticidal protein, a double-stranded RNA, a chemical insecticide, and a biological insecticide. 
     
     
         22 . The method of  claim 1  or  claim 10 , wherein the candidate plant is selected from corn,  Brassica  sp., alfalfa, rice, sorghum, millet, sunflower, safflower, wheat, soybean, and tobacco. 
     
     
         23 . The method of  claim 1  or  claim 10 , comprising obtaining additional non-destructive images of roots of said candidate plant at two or more time intervals. 
     
     
         24 . The method of  claim 23 , wherein the two or more images are compared using imaging software. 
     
     
         25 . The method of  claim 5 , comprising determining the injury to the root tissue by a processor, the method further comprising manually using the non-destructive image to generate the root nodal injury score.