Registration of Soybean Germplasm SS93-6012 and SS93-6181 Resistant to Phomopsis Seed Decay

Soybean [Glycine max (L.) Merr.] germplasm SS93-6012 (Reg. No. GP-362, PI 652442) and SS93-6181 (Reg. No. GP-363, PI 652443) were developed and released by the University of Missouri-Columbia in January 2006 as resistant to Phomopsis seed decay (PSD), caused by Phomopsis spp. Both lines were developed from a cross between MO/PSD-0259 (PI562694) (PSD-resistant MGIV germplasm) and 'Asgrow 3834' (PSD-susceptible MGIII cultivar) made in 1990 at the Bradford Research and Extension Center of the University of Missouri, Columbia, MO. The lines were composited in the F, generation and evaluated for yield and Phomopsis seed decay infection. These lines are highly resistant to Phomopsis spp. SS93-6012 has a relative maturity of 4.2, purple flowers, gray pubescence, an indeterminate growth habit, tan pods at maturity, yellow color seeds, buff hila, and seed weight of similar to 14 g per 100 seeds. SS93-6181 has a relative maturity of 4.0, purple flowers, tawny pubescence, an indeterminate growth habit, tan pods at maturity, yellow color seeds, imperfect black hila, and seed weight of similar to 16 g per 100 seeds. So far, PSD-resistant commercial soybean cultivars are not available, and these two lines may be used for development of PSD-resistant high-yielding soybean cultivars.