POSITIONAL CLONING OF A GENE FOR NEMATODE RESISTANCE IN SUGAR-BEET

Hs1(pro-1) locus confers resistance to the beet cyst nematode (Heterod era schachtii Schmidt), a major pest in the cultivation of sugar beet (Beta vulgaris L.). The Hs1(pro-1) gene was cloned with the use of gen ome-specific satellite markers and chromosomal breakpoint analysis, Ex pression of the corresponding complementary DNA in a susceptible sugar beet conferred resistance to infection with the beet cyst nematode. T he native HS1(pro-1) gene, expressed in roots, encodes a 282-amino aci d protein with imperfect leucine-rich repeats and a putative membrane- spanning segment, features similar to those of disease resistance gene s previously cloned from higher plants.