This work was funded by the National Natural Science Foundation of China (31271799), and the National “Key Sci-Tech” program, China (2013ZX08002-001-004), and the China–Czech Government Science and Technology Cooperation Project (40–3 and LH12196). Editing assistance from Chinese Academy of Agricultural Sciences (CAAS) and from M. Blair is gratefully acknowledged. “
“The filamentous ascomycete fungus Tacrolimus Magnaporthe oryzae is the causal agent of a wide range of diseases including rice blast. It is destructive in several crops and is under intensive study worldwide [1]. The classical method of fungal DNA preparation is multi-step and includes growing the fungus in liquid or solid medium, lyophilizing

mycelia, disrupting cell walls, removing proteins with phenol and chloroform, and precipitating DNA with ethanol or isopropanol. This method is time-consuming and labor-intensive, and results in pollution from the phenol and chloroform compounds. Other procedures for extraction and purification of fungal DNA were modified from the CTAB method originally Small Molecule Compound Library developed for plant tissue extraction [2] using organic solvents [3]. The CTAB

method was considered superior for removing carbohydrates. Although these techniques are available for extraction of fungal DNA, DNA isolation from some fungal mycelia and spores remains difficult. A rapid and simple method for polymerase chain reaction (PCR)-based identification of fungal genotypes increases efficiency and enables the amplification of large numbers of samples in a relatively short time. Such a method would also be useful for screening for known genes and for studying the genetic identity of exotic pathogens under quarantine. Other rapid DNA extraction methods of M. oryzae for different purposes have been reported [4], [5], [6], [7] and [8]. However, PCR amplification of M. oryzae from desiccated filter papers has not. The

objective GNAT2 of this study was to develop a simple and fast method of direct amplification of a known gene in M. oryzae stored desiccated on filter paper for a relatively long time. Direct amplification of a gene of interest using PCR would save time and cost incurred by growing the fungus and then extracting DNA. A total of 28 field isolates of blast fungus purified from a 2012–2013 Arkansas field collection were grown on Wattman filter paper as described by Jia [9]. Specifically, an oatmeal agar piece (0.1 cm in diameter) containing the fungal structures was inoculated onto sterilized filter paper spread on an oatmeal plate [10]. The fungus was allowed to grow for 1–2 weeks under continuous black and white fluorescent light at room temperature between 21 and 24 °C. Filter papers with fungal structures (mycelia and spores) were then dried in a desiccator. The filter papers were then cut aseptically into pieces of 0.5–1.