Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/15/2005
Publication Date: 12/10/2005
Citation: Guo, B., Sleper, D.A., Arelli, P.R., Shannon, J.G., Nguyen, H.B. 2005. Identification of qtls associated with resistance to soybean cyst nematode races 2,3, and 5 in soybean pi 90763. Journal of Theoretical and Applied Genetics. Vol. 111: P 965-971.
Interpretive Summary: Soybean cyst nematode (SCN) causes annual yield losses estimated to be over 1 billion dollars. Use of resistant varieties and rotations of soybean with crops such as corn upon which the nematode cannot feed will minimize yield losses caused this pest. Most of the currently grown resistant varieties have the same major genes for nematode resistance which allows the nematode to adapt to them over time. Soybean PI 90763 may provide new genes for resistance to the nematode. Molecular makers were used to identify new genes for resistance in PI 90763. Use of these markers may reduce the current tedious methods for developing resistant varieties. This information will enable soybean breeders to develop new varieties faster so soybean producers have new weapons to combat the nematode
Technical Abstract: Soybean cyst nematode (SCN) (Heterodera glycines Ichinohe) is a major soybean [Glycine max (L.) Merr.] disease throughout the soybean growing regions in the world, including the USA. Soybean PI 90763 is an important SCN resistance source. It is resistant to several SCN populations including races 2, 3 and 5. But its genetics of resistance is not well known. The objectives of this study were to: (1) confirm QTLs for resistance to SCN race 3 in PI 90763 and (2) identify QTLs for resistance to SCN races 2 and 5. QTLs were searched using 193 polymorphic SSRs covering 20 linkage groups. QTLs associated with resistance to SCN were identified on LGs A2, B1, E, G, J and L. The same QTL was suggested for resistance to different SCN races where their 1-LOD confidence intervals of QTL positions highly overlapped. QTL on LG G was associated with resistance to races 2, 3 and 5. QTL on LG B1 was associated with resistance to races 2 and 5. QTL on LG J was associated with resistance to races 2 and 3. QTLs on LGs A2 and L were associated with resistance to races 3. QTL on LG E was associated with resistance to race 5. We conclude that LGs A2 and B1 may represent an important distinction between resistance to SCN race 3 and resistance to SCN races 2 and 5 in soybean.