Yield Drag Associated with Resistance to Root-Knot Nematodes In High-Yielding Cotton Germplasm

This project describes the potential for introducing yield drag when breeding resistance to root-knot nematodes into cotton.  When genes conferring a desirable trait (e.g., resistance) are introgressed from an inferior genotype, DNA near the desirable gene but conferring deleterious traits may also be incorporated.  Accidental incorporation of deleterious DNA is called linkage drag; if it reduces yield, it is called yield drag.  We documented the occurrence of yield drag in a high-yielding cotton line with resistance to root-knot nematodes when compared to its nematode-susceptible isoline.  However, yield drag was not observed in lower yielding genotypes.