RESUMO
Four different methods were evaluated for extracting RNA from microorganisms of a paddy soil and a upland soil, the RNA quality and quantity were examined. The results showed that method 1 applying liquid nitrogen for grinding gave the highest yield but poor purity, and the additional purification was necessary for further RT-PCR. Method 2 using bead beating yielded the RNA with high purity which could be directly used for RT-PCR, but the RNA yield was lower than that of method 1. Method 3 with the commercial soil RNA extraction kit achieved high quality RNA but the lowest yield and had selectivity for soils. Method 4 is not suitable for extracting RNA from the test soils. Method 1 and method 2 with good performances on soil RNA extraction were applied to other three typical paddy soils including purple calcareous clayey soil, reddish yellow loamy soil, granitic sandy soil. The results showed that method 1 and method 2 were suitable for extracting high quality RNA from these samples, so they might be the effective methods of RNA extraction for paddy soils.
