ARS | Publication request: Linkage Mapping of NBS-LRR Disease Resistance Gene Analogs in Watermelon

Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: March 7, 2010
Publication Date: March 25, 2010
Citation: Harris-Shultz, K.R., Wechter, W.P., Levi, A. 2010. Linkage Mapping of NBS-LRR Disease Resistance Gene Analogs in Watermelon. HortScience. 45:510.

Technical Abstract: Watermelon disease resistance gene analogs (WRGA) from ‘Calhoun Gray’, PI 296341, and PI 595203 were isolated using degenerate primers specific for the nucleotide binding sites (NBS) from the NBS-leucine-rich repeat (LRR) resistance gene family. Following cloning, sequencing, and analysis of these clones, we identified 66 which contained motifs characteristic of NBS-LRR resistance genes. Using cluster analysis, eight groups of WRGA were identified and further characterized as having homology to Drosophila Toll and mammalian interleukin-1 receptor (TIR) and non-TIR domains. Three of these WRGA, as well as three disease-related watermelon expressed sequence tags homologs, were placed on a testcross map. Linkage mapping placed the WRGA on linkage group XIII, clustered with other resistance gene analogs. In addition, these WRGA were amplified from various genera of the Cucurbitaceae indicating that conservation of resistance gene analogs exists among cucurbits. These WRGA-STS markers may be useful in marker-assisted selection for the improvement for disease resistance in watermelon.