Four protocols of soilless substrate DNA extraction were tested in three soilless substrates with different characterization, in order to find an efficient unbiased DNA extraction procedure which could analyze the microbial community structure in soilless substrate samples. Total DNA was extracted from each soilless substrate by the four protocols, and then was purified by Sephadex G-200 spin column after being precipitated by PEG8000. The results showed that more than 97.5% of the humic acids were also removed by Sephadex G-200 spin column. The agarose gel electrophoresis showed that the fragments of crude and purified DNA had a length of about 23 kb. In addition, the restriction map digested by restriction endonucleases showed that each of the protocols was adapted to extract microbial genome DNA from soilless substrate samples. Moreover, the protocol iii showed more bands by denaturing gradient gel electrophoresis analysis and was adapted to extract microbial genome DNA from soilless substrates with higher organic matter and humic.
展开▼
