Genetic Mapping of Resistance to Tetranychus urticae in Maize

The study investigates the genetic basis of resistant in maize (Zea mays) to the spider mite Tetranychus urticae (the two-spotted spider mite). The two-spotted spider mite is a significant agricultural pest of a number of important crop plants, including maize. It is especially important under conditions of drought stress, during which herbivory by T. urticae can cause major damage to leaves and loss of yield. Our approach to identify loci in the maize genome involves using bulk segregant analysis (BSA) genetic mapping. Briefly, sensitive parents and a resistant parent were crossed, and phenotypic extremes were analyzed in replicate in F2 populations (that is, the most sensitive and resistant F2 individuals were identified). The resulting pools were then assessed by Illumina sequencing to detect allele frequency shifts in genomic regions underlying resistance.