The invention overcomes the deficiencies of the art by providing an agronomically elite soybean plant with non-transgenic mutations of at least two of the glycinin subunits selected from the group consisting of Gy1, Gy2, Gy3, Gy4, and Gy5, such as conferring a Gy3 and Gy4 null phenotype and increased .beta.-conglycinin content in seed. The invention also provides derivatives, and plant parts of these plants and uses thereof. Methods for marker assisted selection of soybean varieties comprising non-transgenic mutations conferring a reduced Gy1, Gy2, Gy3, Gy4, and Gy5 phenotype are also provided as part of the current invention. Methods for producing such plants that are further lipoxygenase and/or Kunitz Trypsin Inhibitor null and the plants produced thereby are also provided. The invention is significant in that soybeans from such plants are preferred dietary additives and provide important health benefits.