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 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Comparative Karyomorphological Study between Male and Female Plants of Some Cycas and Zamia Species) ผู้เขียน: ดร.นิตย์ศรี แสงเดือน, รองศาสตราจารย์ ,  Methanee Toahsakul, ดร.วิภา หงษ์ตระกูล, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractThis paper presents the karyotype and the idiogram of known sex plants for five species of Cycas (Cycadaceae) and seven species of Zamia (Zamiaceae). All five species of the genus Cycas had the same chromosome number (2n = 2x = 22) but their karyotype formulae varied into three groups: 10m+10sm+2st, 12m+8sm+2st and 14m+8sm. The karyotype of male and female Cycas plants could be clearly distinguished by the satellite chromosomes. All seven species of the genus Zamia varied in both chromosome numbers (2n = 2x = 16 up to 2n = 2x = 24) and karyotype formulae. It was difficult to differentiate between the male and female plants of the Zamia spp. by karyotyping because of the lack of satellite chromosomes in both sexes. |
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หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Analysis of Sex Determination in Some Cycads Using Methylation- Sensitive Amplification Polymorphism (MSAP)) ผู้เขียน:ฐิติ กาญจนเกตุ, ดร.วิภา หงษ์ตระกูล, รองศาสตราจารย์, ดร.นิตย์ศรี แสงเดือน, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractThis 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. |
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