E78 remained under the virulence threshold (pinpoint necroses only). There was no significant difference in lesion size (P < 0.05) between the endophytic isolate E70 and the pathogenic isolate CCP on cultivar FDR 5788, with significant symptoms present at 5 dpi, which dramatically increased by 9 dpi. Fig. 3 Pathogenicity of four endophytic C. cassiicola isolates in a detached-leaf assay under controlled conditions. Isolates were inoculated onto the detached leaves of their respective original

host rubber tree cultivar and pathogenic CCP strain was used as a control for both cultivars. click here For each isolate, six leaves were inoculated, each with ten drops of conidia suspension and one drop of water as untreated control. The lesion area per leave was measured manually, at 5 and 9 dpi. The entire experiment was conducted three times. Panel a: Symptoms Intensity expressed as the mean lesion area ± the standard error from the 18 inoculated leaves. For

each cultivar, values followed by the same letter were not significantly different, according to Tukey’s HSD test (P < 0.05). Panel b: Visual symptoms Kinetics of mycelium development in the leaf tissues post-inoculation The amount of mycelium that colonized rubber tree selleck inhibitor leaf tissue, post-inoculation was quantified by real-time PCR by calculating the relative expression (Qr) of a C. cassiicola-specific EF1a gene normalized to a rubber tree-specific polyubiquitin gene 1, 2, 5 and 9 dpi (Fig. 4). In the RRIM 600 cultivar (Fig. 4a), EF1a relative expression (Qr) was already detectable 1 and 2 dpi for E139 and CCP, while it was very low (nearly undetectable) for the other strains, suggesting that colonization of mycelia for these two strains started earlier, which is in agreement with their higher aggressiveness compared to E78 and E79. The Qr increased and reached a maximal level at 9 dpi, which was similar for both E139 and CCP. The development of E79 mycelium started later (between 2 dpi and 5 dpi) but finally reached levels similar to those of E139 and CCP at 5 and 9 dpi. In contrast, E78 mycelium colonization remained very low even at 9 dpi. In the FDR 5788 cultivar (Fig. 4b), the mycelium growth of both CCP and

E70 was detectable as early as 1 dpi and strongly increased over time. Both strains presented check details similar profiles at 2, 5 and 9 dpi, although the mycelial growth may have started earlier for E70 than CCP. Fig. 4 Colonization of C. cassiicola mycelia in rubber tree leaf tissues post-inoculation measured by real-time PCR. The kinetics of C. cassiicola mycelia growth at 1, 2, 5 and 9 days post inoculation of the (a) RRIM 600 cultivar and (b) FDR 5788 cultivar were quantified by calculating the relative expression (Qr) of a C. cassiicola-specific EF1α gene normalized to a rubber tree-specific polyubiquitin gene. Data presented are means ± standard error of three independent replicates. Values followed by the same letter were not significantly different according to Tukey’s HSD test (P < 0.