Breeding to develop root-knot nematode (Meloidogyne spp.) resistant crop plants typically relieson labor intensive and expensive phenotype screensof segregating progenies.Screens for resistance rely on assays of nematode reproductionor indices of root-gall symptoms which are often variable even under controlled conditions.Application of molecular marker and large-scale genotyping approaches for indirect selection of resistance loci are now available in major crops for breeding enhancement.We have developed and appliedmolecular breeding (MB) in grain legumes,cotton and carrot for root-knot nematode resistance.Common root-knot nematode species (M.incognita, M.javanica, M.arenaria, M.hapla) are highly damaging to one or more of these crops and in cowpea and cotton also act as components of disease complexes with soil-borne Fusarium wilt fungi (Fusarium oxysporum f.sp.tracheiphilum in cowpea and F.oxysporum f.sp.vasinfectum in cotton).Effective resistance genes for these pathogens are available for cultivar improvement.We have made extensive use of advanced recombinant inbred line (RIL) and other populations segregating for resistance to identify genome locations of resistance trait determinants by QTL mapping.Combining phenotype data from field and controlled environment infection assays with SSR and SNP genotyping profiles provided resistance QTL with flanking markers for indirect selection.Genome-wide SNP marker coverage enables both foreground (trait-based) and background selection, combining targeted resistance loci together with genome regions carrying favorable growth,yield and other stress tolerance traits.Examples of MB are presented demonstrating the effects of single and combined resistance traits for M.incognita and Fusarium wilt in cotton and M.incognita and M.javanica in cowpea and carrot.