1. A method of creating a population of soybean plants with a low iron growth condition tolerant phenotype, said method comprising: a. genotyping a first population of soybean plants or seeds; b. detecting in said first population of soybean plants or seeds, a polymorphic nucleic acid marker linked by less than or equal to 10 cM to an allele of SEQ ID NO:70, wherein said allele of SEQ ID NO:70 is associated with a low iron growth condition tolerant phenotype; c. selecting based upon said genotyping a soybean plant or seed containing said allele that was detected by genotyping; d. crossing or selfing said selected soybean plant or a plant produced from said selected seed; and e. producing from said crossing or selfing a population of progeny plants comprising said allele of SEQ ID NO:70 that is associated with the low iron growth condition tolerant phenotype; wherein said allele of SEQ ID NO:70 comprises an Adenosine at position 201.