Evaluation of a Soybean Breeding Population for Iron Content as a Predictor of Resistance to Iron Deficiency Chlorosis.

Iron deficiency chlorosis (IDC) is a nutritional disease of soybean (Glycine max) that can result in a severe yield penalty or even death.  Resistance to the disease has been limited, with no known cultivar possessing complete resistance. Iron content in the seed could be used as an estimator of IDC resistance in early growing stages of soybean, when symptoms are usually observed. We evaluated two near-isogenic lines (NILs), Clark (Fe-efficient) and Iso-Clark (Fe-inefficient), and Pride B216 (Fe-inefficient) and A15 (Fe-efficient) as well as progeny (F_2:4) of the cross Pride B216 x A15 to quantify the amount of Fe content in seed. Preliminary evaluations of the NILs suggested that iron content in seeds is higher in the Fe-efficient parent than in the Fe-inefficient parent.  A similar relationship was observed when comparing Fe content in seed of A15 (Fe-efficient) and Pride B216 (Fe-inefficient). Identification of lines that are Fe-efficient and have high Fe content in seed could aid in development of better Fe-efficient cultivars to grow on calcareous soils.