Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/21/2006
Publication Date: 2/6/2007
Citation: Donald, P.A., Kilen, T.C., Mengistu, A. 2007. Registration of soybean germplasm line d99-2018 resistant to Phytophthora rot (Rps6) and soybean cyst nematode races 3 (HG Type O) and 14 (HG Type 126.96.36.199). Crop Science. Vol 47:451-452. Interpretive Summary: Soybean cyst nematode, a microscopic-sized worm, causes the largest yield loss overall in soybean production fields in the USA. Phytophthora rot, a disease of soybean caused by a fungus, can severely limit yield in poorly drained clay soils found in the Mississippi Delta. D99-2018 was released to provide soybean breeders with an additional soybean line with resistance to these two pests. This germplasm line will allow breeders to incorporate a different source of Phytophthora rot resistance, creating custom lines for specific geographic areas that have a need for different sources of resistance to this disease. Use of this germplasm with the combined resistance to two pests in a desirable agronomic background should shorten the length of time needed to develop soybean varieties used by farmers. Resistance to these two pests is an important management tool for farmers, especially in fields with poorly drained soils.
Technical Abstract: D99-2018 was developed by backcrossing. It was selected in the 5th generation from the cross Bedford x Altona. The original donor of Rps6 was the Maturity Group 00 cultivar Altona. Rps6 provides resistance to races 1-4, 10, 12, 14-16, 18-21, and 25 of the first 27 identified races of P. sojae. D99-2018 is similar to Bedford for all observable traits and has the same level of resistance to the soybean cyst nematode (Heterodera glycines), races 3 (HG Type 0) and 14 (HG Type 188.8.131.52), as Bedford. D99-2018 was in replicated yield tests on clay soil at Stoneville, MS for 3 years. Seed yield for Bedford and D99-2018 were 18.8 and 25.8 Bu/A, respectively in 2000; 14.9 and 31.1 Bu/A respectively, in 2001; and 48.6 and 56.1 Bu/A, respectively, in 2002. Seed yield differences were significant at the 5% level in 2000, and at the 1% level in 2001 and 2002.