FREEZE-DRYING OF OIL PALM (Elaeis guineensis) LEAF AND ITS EFFECT ON THE QUALITY OF EXTRACTABLE DNA

摘要

The use of molecular genetic markers in plant breeding and genetic resource management in oil palm requires the analysis of large numbers of samples and the availability of rapid and efficient DNA extraction methods. This often requires leaf samples to be stored in an ultra low temperature freezer for future use. This takes up valuable freezer space. Thus, freeze-dry ing is proposed as an alternative. Thefreeze-dried tissue can be ground into dry powder for efficient storage in freezers. This paper describes a method to freeze-dry oil palm leaf and compares the quality of genomic DNA extracted from non-freeze-dried and freeze-dried leaves. The effects of storage temperature (-20℃ and 4℃) and duration (up to 18 months) on the DNA stability in thefreeze-dried leaf were also evaluated. The freeze-dried leaf yielded high molecular weight DNA of sufficient purity and quality for molecular biology applications. The study demonstrated that freeze-dried oil palm leaves can be stored at -20℃ and 4℃ for at least 18 months with no DNA degradation. DNA prepared from thefreeze-dried leaves was also acceptable for both RFLP and SSR analyses. Freeze-drying oil palm leaf provides an economical solution to long-term storage and handling because of the reduced weight and space requirement. In addition, up to four times as many samples can be processed for DNA isolation per day per person using freeze-dried powder of oil palm leaves, compared to using fresh tissue or tissue frozen in liquid nitrogen.