Contamination problems on DNA isolation from 'recalcitrant plant taxa' which is rich in polysaccharides have been commonly encountered in a wide range of research fields such as plant population biology, biodi...Contamination problems on DNA isolation from 'recalcitrant plant taxa' which is rich in polysaccharides have been commonly encountered in a wide range of research fields such as plant population biology, biodiversity, and molecular marker-assisted breeding. Here we present an improved protocol to extract DNA efficiently from dry or fresh leaves of a 'recalcitrant plant taxa', Betula alnoides Buch. Ham. ex D. Don in which three key steps are involved: 1) washing out most of polysaccharides and other secondary compounds with CTAB-free buffer from homogenate; 2) adoption of 3% CTAB rather than 2% CTAB in the exaction medium; and 3) using of high concentration of salt prior to DNA precipitation with isopropanol to remove residual polysaccharides. The isolated DNA has been proved suitable for RAPD-PCR amplification and restriction digestion. This modified procedure is simple, inexpensive and reliable, and is also applicable to many other plant taxa with high polysaccharides.展开更多
文摘Contamination problems on DNA isolation from 'recalcitrant plant taxa' which is rich in polysaccharides have been commonly encountered in a wide range of research fields such as plant population biology, biodiversity, and molecular marker-assisted breeding. Here we present an improved protocol to extract DNA efficiently from dry or fresh leaves of a 'recalcitrant plant taxa', Betula alnoides Buch. Ham. ex D. Don in which three key steps are involved: 1) washing out most of polysaccharides and other secondary compounds with CTAB-free buffer from homogenate; 2) adoption of 3% CTAB rather than 2% CTAB in the exaction medium; and 3) using of high concentration of salt prior to DNA precipitation with isopropanol to remove residual polysaccharides. The isolated DNA has been proved suitable for RAPD-PCR amplification and restriction digestion. This modified procedure is simple, inexpensive and reliable, and is also applicable to many other plant taxa with high polysaccharides.
