DNA methylation and genetic diversity analysis of genus Cycas in Thailand
10 Cycas species as well as one subspecies localized in Thailand were studied using the methylation sensitive amplification polymorphism (MSAP) technique. 11 MSAP primer combinations were used and 720 MSAP bands were generated. The percentages of DNA methylation estimated from MSAP fingerprints were in the range of 36.05 to 57.44%. MSAP fingerprints were also used for phenogram construction and principal component analysis were based on nucleotide and methylation polymorphisms. Genetic similarity estimated from nucleotide polymorphism among these cycads ranged from 0.86 to 0.92. Cluster analysis using nucleotide and methylation polymorphisms resulted in different groupings for some cycads. The results show that polymorphisms of Cycas in Thailand were not only limited in the nucleotide level but also in the pattern of DNA methylation. It was proposed that the percentage and pattern of DNA methylation as well as nucleotide polymorphism were sources of variation in these cycad species.
Key words: Cycas, DNA methylation, genetic diversity, methylation sensitive amplification polymorphism (MSAP).