Pathogen identification of leaf spot disease of oil palm seedling and determination of its biological characteristics.

Pathogen of oil palm leaf spot disease was isolated and purified, and referred to as strain YZ-4. According to its morphological characteristics and the sequence of internal transcribed spacer (ITS), the strain YZ-4 was identified as Pestalotiopsis microspore. Results of biological characteristics showed that the optimum temperature and pH for YZ-4 mycelia growth were 28-30°C and 6.0-8.0 respectively, while the highest rate of conidium germination occurred at 25-30°C, and pH 6.0-9.0. The most efficient utilized carbon sources by mycelium were D-maltose and soluble starch. When soluble starch, D-maltose, D-galactose and glucose were used separately as carbon sources, YZ-4 conidial germination rates were 94.33%, 88.33%, 90.00%, and 89.67% respectively. These rates were not significantly different. Peptone was the most efficient nitrogen source. As peptone and potassium nitrate were separately used by YZ-4 as nitrogen sources, the corresponding conidial germination rates were 80.33% and 74.00% respectively. [ABSTRACT FROM AUTHOR]