Optimized protocol for ramie mtDNA extraction based on sucrose-mediated sedimentation method.

The extraction of mtDNA was difficult than that of gDNA,due to a high content of secondary metabolic products such as polysaccharides,hydroxybenzene and flavone in ramie [Boehmeria nivea(L.) Gaud],an optimized protocol for ramie mtDNA extraction based on sucrose-mediated sedimentation was proposed.Antioxidant was added into the extraction buffer,which could prevent the solution from browning.High concentration salt solution of 4 % NaCl was used to remove polysaccharides in the extraction process with chloroform-isopentanol.The mtDNA templates extracted with the above modified method presented better band patterns in ISSR-PCR amplification,indicating that the combination of sucrose-mediated sedimentation method with antioxidant and high salt solution was suitable for the extraction of ramie mtDNA.