Comparative Research on Isolation and Purification Method for Genomic DNA of Cunninghamia lanceolata

The DNA samples of Cunninghamia lanceolata were prepared by Carbamide method,Sodium citrate method,the modified CTAB method and SDS method,respectively.The results showed that improved CTAB method was suitable for extracting the genomic DNA from C.lanceolata.DNA samples obtained by this method possessed the standard ultraviolet absorbance spectrum of pure natural DNA,whose A_(260)/A_(280) was 1.80 or so,degradation was light and impurity was little.However,Carbamide method and Sodium citrate method could not extract the genomic DNA and SDS method was difficult to get rid of polyhexose completely. Therefore,the three methods were not suitable for extracting the genomic DNA.When tested through the restriction enzyme analysis,the DNA samples prepared by the modified CTAB method could meet the next experiment requirement perfectly.The yield of DNA of young leaves,old leaves,young shoots and young stems obtained by the improved CTAB method were 158.4μg/g,129.6μg/g,177.6μg/g and 98.40μg/g.Young leaves could directly use to extract the genomic DNA after taking the convenience of sample collecting into account.