Localization of A. citrulli in watermelon seed. The expected
amplicon was produced with 100% of the extracts from pericarpand
pistil inoculated seed samples that were spiked with A. citrulli
DNA (data not shown) indicating no PCR inhibition. Overall, the
tissue colonization results obtained by the real-time PCR assay
were not significantly different to those obtained by plating on
semiselective agar media (P > 0.05) (Table 2). For pericarpinoculated
seed lots, the real-time PCR assay indicated that 5.3%
of the testae samples were contaminated with A. citrulli while
6.3% of testae samples from pistil-inoculated lots were positive
(Table 2).