Plant & Animal Genome VI Conference

P84

IDENTIFICATION OF ALFP MARKERS FOR RESISTANCE TO CYST NEMATODE (Heterodera glycines) IN SOYBEAN.

1. Department of Natural Resource Science and Landscape Architecture, University of Maryland, College Park 20742.
2. Department of Entomology, University of Maryland, College Park 20742.

Soybean cyst nematode (SCN) is a major pest of soybean causing large grain yield losses. Molecular markers linked to cyst nematode will be useful in breeding for resistance. Amplified Fragment Length Polymorphisms and Bulk Segregate Analysis techniques were applied to an inbred population with the intention to identify molecular markers linked to cyst nematode resistance. F₈ recombinant inbred lines derived from the cross of Forrest (resistant to races 1 & 3 of cyst nematode) and Essex (susceptible) were used in this study. We analyzed approximately 600 selectively amplified DNA fragments using 48 primer combinations and identified one marker tightly linked to a cyst nematode resistance gene. The marker from the above study was subsequently used to screen a population of 96 F_5:6 inbreds (segregating for a cyst nematode resistance gene) from the cross Hartwig (resistant to all known races of cyst nematode) and SL89-134 (susceptible). The presence and absence of the marker in the 96 inbreds was scored and the linkage analysis was done with Mapmaker.