Analysis of Sex Determination in Some Cycads Using Methylation- Sensitive Amplification Polymorphism (MSAP)

บทคัดย่อ

This is the first report on the analysis of sex determination in cycads using MSAP technique. Prior works using cytogenetic techniques, molecular markers such as random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) did not clearly identify sex in
cycads. This modified AFLP technique using isochizomer enzyme (MspI and HpaII) called methylationsensitive amplification polymorphism (MSAP) was carried out to assess the pattern of cytosine methylation in both sexes of Cycas and Zamia. Using seven pairs of primers, 364 bands some of which showing sex-specific were produced and classified into three groups. The first group was non-polymorphic markers, whereas the second group was chosen from the results of differentation ability of MspI and HpaII to cut the methylated sequences, but sex-different markers were not obtained. Markers in the third group were methylation-sensitive and they also showed some polymorphic patterns between the two sexes. We suggested that sex in cycads may be associated with DNA methylation, but further study is required to reach a conclusive result.