Phylogenetic comparisons of Cucurbitaceae CC-NBS family of NBS-encoding genes and NBS-encoding genes with those in Arabidopsis . The ancient CC family (N1 to N4) as defined by Cannon et al.  is indicated. The scale represents the average number of substitutions per site. The numbers on the branches indicate the percentage of 1000 bootstrap replicates which support the node with only values of > 50% reported. The detailed phylogenetic tree is shown in Additional file 9.