Author
Arelli, Prakash |
Submitted to: International Crop Science Congress Proceedings
Publication Type: Proceedings Publication Acceptance Date: 3/29/2008 Publication Date: 5/1/2008 Citation: Arelli, P.R. 2008. Genetics of Resistance in Glycine Max Accessions to Heterodera Glycines. International Crop Science Congress Proceedings. 5:148-149. Interpretive Summary: Technical Abstract: Worldwide, cyst nematode (Heterodera glycines) is the most destructive pathogen on cultivated soybean (Glycine max). In the USA, yield losses in 2001 were nearly 60 million dollars. Crop losses are primarily reduced by the use of resistant cultivars. Nematode populations are variable and have adapted to reproduce on resistant cultivars over time because resistance primarily traces two accessions, Peking and PI88788. Recently, soybean cv. Hartwig was released which has comprehensive resistance to most nematode populations. Virulent nematodes have adapted to reproduce on Hartwig including its primary source of resistance, PI437654. It is necessary to develop soybean germplasm for durable resistance using new sources of resistance. Researchers have been evaluating world soybean germplasm collection for sources of resistance and currently 118 soybean accessions are available with resistance to one or more HG Types/Races. Cluster analyses have identified genetically unrelated unique soybean accessions. These include PI567516C, PI494182, PI438489B, PI507354, and PI567286. Traditional genetic analyses and molecular mapping methods in unique accessions have identified gene/s or QTLs associated with nematode resistance. Three genes(Rhg, rhg, rhg) in PI567516C condition resistance to virulent nematode population LY1. Tentatively, marker Satt592 on LG O is mapped to resistance region. Another three-gene model is proposed for resistance in PI494182 to nematode Races 1, 3, and 5. Mapping is in progress. Resistance in PIs438489B and 507354 is conditioned by three or four-gene models, respectively. QTLs associated with resistance are primarily mapped to LGs A1, A2, C2, D1a, G and J in newly identified soybean accessions. |