Resumo de basal rot

Basal Stem Rot (BSR) is a “white rot” disease caused by the fungi Ganoderma spp, which affects Oil Palm (OP) cultivation. In previous reports, ergosterol has been used to detect growth of “white rot” fungi. This compound is a cell membrane primary sterol specific to fungi and is frequently used to detect fungal invasion in various substrates. Based on these considerations ergosterol was determined in a G. boninense isolate from decayed OP, artificially inoculated oil palm seedlings samples of sound and decayed OP stem removed previously from whole OP and whole OP demonstrating disease symptoms in the field, by the non-alkaline ergosterol extraction (NAE) and the quantification of ergosterol concentrations was determined by HPLC analysis. Ergosterol was detected from the G. boninense isolate and the concentration increased directly with the increase of biomass with a range of ergosterol concentrations varying from 30.6 µg g-1 to 170.3 µg g-1 at mycelial biomass of 0.1 g and 2.0g, respectively. The ergosterol concentration also increased significantly with the increase in the degree of root infection, reaching the highest concentration at 10.34 µg/g on week 22 with >50% of root infection. Ergosterol was detected in all infected OP samples with respect to the OP section method and was absent in healthy samples and the average concentrations for healthy, low, medium and highly-infected OP were 0.00, 3.90, 16.11, and 29.72 µg g-1 OP, respectively. Ergosterol was detected in all infected OP samples using the standing OP method and absent in all healthy palm samples and its mean concentrations for healthy, low and severely-infected OP were 0.00, 2.56, and 26.22 µg g-1 OP respectively. Finally, the present paper represents the first report for detection of ergosterol from G. boninense and demonstrates that the sterol can be employed to quantify and detect the BSR symptoms in