Some of your favorite clothes, towels and sheets might be made with cotton, America's best-selling fabric. But cotton plants won't produce top yields of the fluffy white bolls if they're clobbered by a microbe known as FOV race 4, short for Fusarium oxysporum f.sp. vasinfectum.

Now, studies by Agricultural Research Service (ARS) scientist Mauricio Ulloa and cooperators may lead to new ways to combat the disease.

The Fusarium fungus can clog a plant's vascular system, or "plumbing," according to Ulloa. He's a geneticist at the ARS Western Integrated Cropping Systems Research Unit in Shafter, Calif.

Already, Ulloa, ARS colleague Richard Percy at College Station, Texas, and Michael Davis and Robert Hutmacher of the University of California have developed four new kinds of Fusarium-resistant pima cotton plants. Pima cotton makes premium fabrics for clothing and home.

The scientists will offer these parent pimas, known as SJ-07P-FR01 through -FR04, to cotton breeders and researchers this year. The plants rank as the first publicly owned pimas that have good resistance to race 4; good-to-superior fiber length, which is important to fabric quality; and moderate yields, according to Ulloa.

Now the scientists are testing hundreds of upland cotton plants. Upland cotton offers excellent, less expensive fibers. And, in related studies, Ulloa and co-investigators are delving more deeply into cotton's genetic makeup.

The intent? To find markers — genetic material that indicates the presence of genes of potential interest. The scientists have already identified a significant number of markers that may prove to be indicators of Fusarium resistance.