Early detection of somaclonal variation in oil palm callus culture through cytological and SDS-PAGE protein analysis

The major problem of oil palm in vitro propagation is the occurrence of somaclonal variation. This study aimed to obtain somaclonal variation analytical method based on chromosome activities and protein molecular weight level using SDS-PAGE technique on callus culture. Generally, three types of callus were observed, i.e. rooty, nodular friable, and nodular aggregate callus. During mitotic analyses, normal and abnormal cell division of each callus was successfully observed in several phases of mitotic. Rooty callus showed the highest rate of abnormal mitotic divisions up to 7.0 %. In contrast, nodular friable resulted in 3.2 % abnormality rate which is even less than normal plant cell division that was 3.7 %. The most mitotic abnormality type was a reduction-grouping mechanism of the chromosome during methaphase and prophase. SDS-PAGE revealed different protein molecular weight between nodular friable, nodular aggregate, and rooty callus. Protein 20 kDa is a specific protein found in nodular friable callus; this protein was known as a biochemical marker to distinguish embryogenic and non-embryogenic callus.