Registration of AR10SDS Soybean Germplasm Partially Resistant to Sudden Death Syndrome and Resistant to Soybean Cyst Nematode

Disease resistance is an important crop trait that protects yield and farmers’ incomes. The objective of the soybean breeding program for disease resistance at Iowa State University (ISU) is to develop germplasm lines for Iowa. AR10SDS (Reg. No. GP-391, PI 669816) is the first sudden death syndrome (SDS) partially resistant line released by ISU, Project nos. 4403 and 0159 (Agronomy and Plant Pathology departments), ISU Research Foundation (ISURF) Docket #03264. AR10SDS is partially resistant to Fusarium virguliforme which causes SDS, and resistant to soybean cyst nematode (SCN) phenotypic race 3 (HG types 0 and 7) caused by Heterodera glycines. AR10SDS is a bulk of 60 F 3:8 plants uniform in plant and seed traits. The parentage is ‘Ripley’ × ‘IA1008’. Ripley is resistant to SDS. IA1008 is resistant to SCN. The cross and generations advances were made in Puerto Rico beginning in 2000, ISU research site at the Isabela Substation, University of Puerto Rico, Isabela, PR. Yield was evaluated from 2003 to 2006 in Iowa and in the northern U.S. regions. From 2003 to 2011, SDS resistance was evaluated under greenhouse conditions and in SDS-infested field soil. Soybean cyst nematode screening was conducted in 2005 to 2006 under greenhouse conditions. Three SDS resistance quantitative trait loci (QTLs) were inherited from Ripley, and two SCN resistance QTLs from IA1008. Seed yield is similar to IA1008 and significantly ( P = 0.05) better than ‘Parker’ and ‘Freeborn’. It is of early- to mid-maturity group I and adapted from 40 to 42° N latitude. AR10SDS may serve breeding programs for its dual disease resistance.