Expression stability of candidate reference genes in <i>Xcv</i>-infected and mock-treated tomato plants evaluated by geNorm.

<p>Tomato reference genes were ranked based on expression stability calculated by geNorm. New reference gene candidates are indicated in bold. <i>M</i> values represent the average expression stability of each gene (n = 48). The cut-off value for reliable reference genes is indicated by a dashed line.