Analysis of Root-Knot Nematode Resistance in Cotton Cultivars.

Abstract for ASA Southern Regional

The root-knot nematode (Meloidogyne spp.) is a major pest of cotton, accounting for 2.2%, or 414,700 bales, of crop loss in 2016. Host-plant resistance is the most economical control method, as cultural and chemical methods are expensive or otherwise unfeasible. This study is being conducted to analyze the heritability and efficacy of root-knot nematode (RKN) resistance sources. Ten RKN resistant cotton varieties were crossed with three susceptible varieties, to produce 30 F1 genotypes. All of the F1 genotypes were advanced in the field to F2. Ten of the F1 genotypes were selected to advance in the greenhouse during the winter, and the resultant F2s were advanced in the field to F3s. The 13 parent varieties, the 30 F2s and the 10 F3s were planted in the greenhouse in 12 replications in a complete randomized design and inoculated with RKN eggs. Plants were harvested after 50 days and evaluated for RKN resistance through RKN egg counts and root-gall indices.