The RT-PCR detection and distribution of ApMV in apple producing area of China Extraction of High Quality Total RNA from Ammopiptanthus mongolicus with Improved Trizol Method Guanidine Thiocyanate Method of Total RNA Isolation in Platanus aceriflia Construction of cDNA Library from Cucumber Leaves Infection by Pseudoperonospora cubensis and Screening of Resistance-related Genes An Improved Method Suited to Extract Total RNA Used to RT-PCR from Fir Plant RNA Extraction and RT-PCR detection of Dendrobium candidum Extraction of Total RNA from Horned-gall and the Cloning of ACTIN Gene Fragment Extraction of totle RNA from dry Grimmia pilifera Construction of cDNA Library from Cucumber Leaves Infection by Pseudoperonospora cubensis and Screening of Resistance-related Genes Comparison of four methods and their efficiency for total RNA extraction from leaves of pinellia ternata