Methods and Compositions for Selecting Soybean Plants Resistant to Brown Stem Rot

Abstract

The present invention is in the field of plant breeding and disease resistance. More specifically, the invention includes methods and compositions for breeding soybean plants containing quantitative trait loci that are associated with resistance to Brown Stem Rot (BSR), a fungal disease associated with Philophora spp. The invention further includes germplasm and the use of germplasm containing quantitative trait loci (QTL) conferring disease resistance for introgression into elite germplasm in a breeding program for resistance to BSR.

1 . A method of identifying a soybean plant comprising at least one allele associated with Brown Stem Rot (BSR) resistance in a soybean plant comprising the steps of:
 (A) genotyping at least one soybean plant with respect to one or more soybean genomic DNA markers selected from the group consisting of SEQ ID NOs: 1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 14, 16, 18, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 32, 34, 35, 36, and 37; and   (B) selecting at least one soybean plant comprising an allele of said marker associated with Brown Stem Rot (BSR) resistance, thereby identifying a soybean plant comprising at least one allele associated with Brown Stem Rot (BSR) resistance.   
     
     
         2 . The method according to  claim 1 , wherein at least two soybean genomic DNA markers selected from the group consisting of SEQ ID NOs: 1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 14, 16, 18, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 32, 34, 35, 36, and 37 are genotyped in at least one soybean plant in step (A). 
     
     
         3 . The method according to  claim 2 , wherein at least five soybean genomic DNA markers selected from the group consisting of SEQ ID NOs: 1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 14, 16, 18, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 32, 34, 35, 36, and 37 are genotyped in at least one soybean plant in step (A). 
     
     
         4 . The method according to  claim 1 , further comprising the step (C) of assaying said selected soybean plant for resistance to a BSR-inducing fungus. 
     
     
         5 . The method according to  claim 4 , wherein said BSR-inducing fungus is a  Philophora  sp. 
     
     
         6 . The method according to  claim 1 , wherein said an allele of said marker associated with Brown Stem Rot (BSR) resistance is provided in Table 6. 
     
     
         7 . The method of  claim 1 , wherein genotyping is effected in step (A) by determining the allelic state of at least one of said soybean genomic DNA markers. 
     
     
         8 . The method of  claim 1 , further comprising the step of crossing the soybean plant selected in step (B) to another soybean plant. 
     
     
         9 . The method of  claim 1 , further comprising the step of obtaining seed from the soybean plant selected in step (B). 
     
     
         10 . The method of  claim 1 , wherein at least one soybean plant in the segregating population is genotyped with respect to a soybean genomic DNA marker selected from the group consisting of SEQ ID NOs: 1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 14, 16, 18, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 32, 34, 35, 36, and 37 and with respect to another soybean genomic DNA marker selected from the group consisting of SEQ ID NO: 33. 
     
     
         11 . The method according to  claim 1 , wherein said soybean plant that is genotyped in step (A) is from a segregating population obtained by crossing at least one Brown Stem Rot (BSR) resistant plant comprising at least one first genotype with at least one other plant comprising at least one second genotype. 
     
     
         12 . A method of introgressing a BSR resistance allele into a soybean plant comprising the steps of:
 (A) crossing at least one BSR resistant soybean plant with at least one BSR sensitive soybean plant in order to obtain a segregating population;   (B) genotyping at least one soybean plant in the segregating population with respect to a haplotype characterized by one or more soybean genomic DNA markers selected from the group consisting of SEQ ID NOs: 1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 14, 16, 18, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 32, 34, 35, 36, and 37; and   (C) selecting from the segregating population one or more soybean plants comprising a haplotype associated with BSR resistance, wherein the BSR resistance haplotype is associated with a Rbs BSR resistance locus, thereby introgressing a BSR resistance allele into a soybean plant.   
     
     
         13 . The method of  claim 12 , wherein the Rbs BSR resistance locus comprises Rbs1, Rbs2, or Rbs3. 
     
     
         14 . The method of  claim 12 , wherein the Rbs BSR resistance locus is selected from the group consisting of Rbs1, Rbs2, and Rbs3. 
     
     
         15 . The method of  claim 12 , wherein the source of Rbs is elite germplasm. 
     
     
         16 . The method of  claim 12 , wherein the source of Rbs is accession germplasm. 
     
     
         17 - 25 . (canceled)