1a.Objectives (from AD-416):
1) Identify new sources of resistance and introgress resistance genes into desirable agronomic backgrounds;. 2)Phenotype mapping populations for developing new DNA markers and confirm resistance.
1b.Approach (from AD-416):
Screen soybean germplasm using standardized methods in greenhouse assay. Phenotype mapping populations from other scientists. Evaluate for presence of DNA markers using PCR reactions for Marker assisted selection.
This is a collaborative research project funded by the United Soybean Board (USB) via Southern Illinois University. For broadening the resistance in soybean, additional soybean germplasm from USDA Soybean germplasm Collection continue to be screened for identifying new sources of resistance to soybean cyst nematode. Progenies derived from crosses AR03-361091 x PI437655; AR2001 x PI404166, AR05-150140 x PI567516C and AR05-150140 x PI567568A in maturity groups ranging from I to III were evaluated for nematode resistance using DNA markers tagged to resistance in marker assisted selection. Seven DNA markers were identified by USDA-ARS scientists at Jackson, TN. These included Satt 309, Satt 632, Sat_168, Satt 574, Satt 592, Satt 331 and Sat_274. ARS scientists have improved methods for polymerase chain reaction (PCR) which is used for marker assisted selection. This biotechnological method is more efficient and quicker in identifying resistant soybean lines. The greenhouse screening and development of desirable source materials are in progress; the data are shared among collaborators.