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 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Molecular Identification of Cycas by Restriction Fragment Length Polymorphism (RFLP) and Random Amplified Polymorphic DNA (RAPD)) ผู้เขียน: พัทธมน แสงอินทร์,  นางอมรา ทองปาน, รองศาสตราจารย์ , Anders J. Lindstrom, ดร.มิ่งขวัญ มิ่งเมือง, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractRAPD and RFLP were used to identify nineteen species of Cycas. Ten species of these Cycas namely C. chamaoensis, C. macrocarpa, C. pectinata, C. clivicola, C. pranburiensis, C. litoralis, C. tansachana, C. siamensis, C. nongnoochiae and C. simplicipinna are locally found in Thailand while the nine remaining species of C. seemannii, C. wadei, C. bougainvilleana, C. chevalieri, C. diannanensis, C. nathorstii, C. edentata, C. parvulus and C. micholitzii are from several countries around the world but collectively planted at Nong Nooch Tropical Botanical Garden. In the RAPD study, twenty random primers were screened to amplify the genomic DNA of nineteen species of Cycas. Only five primers, i.e., OPB-1, OPB-8, OPB-14, OPB-15 and OPB-17 of ten nucleotides long were found to give polymorphic DNA patterns. These eighty-seven bands of Cycas DNA at the size of 0.35 -2.5 kb could be used to indicate the differences of these Cycas. As for RFLP, three probes were synthesized from 5S rRNA gene, 5S rRNA repeat unit gene of C. clivicola and 18S rRNA gene of C. pranburiensis. The probes were hybridized with the genomic DNA of Cycas which had been digested with restriction enzymes BamHI, EcoRI and DraI. The phylogenetic trees were constructed based on their similarity index derived from DNA polymorphism of RAPD and RFLP separately. The RAPD data classified nineteen species of Cycas into two major groups which mostly corresponded to their geographic origins, i.e., one group of Thailand origin and another of other countries. However, the RFLP data gave a different set of grouping showing more to their morphological characteristics but less on their geographic origins. |
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หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Phylogenetic Relationships Within Cycadaceae Inferred from Non-Coding Regions of Chloroplast DNA) ผู้เขียน:พัทธมน แสงอินทร์, Anders J. Lindstrom, Goro Kokubugata, นางสาวมินตา ชัยประสงค์สุข, อาจารย์ , ดร.มิ่งขวัญ มิ่งเมือง, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractThe intrageneric relationships among 24 species of five Cycas sections based on the combined data of three non-coding regions of chloroplast DNA: trnS-trnG, psbM-trnD and trnL-trnF, were determined using Neighbor-joining, Maximum parsimony and Maximum likelihood methods. All three methods showed similar topology, which divided Cycas into several clades. The first clade consisted of two sections, Cycas and Indosinenses, while the other clades contained Asiorientales, Wadeanae and Stangerioides, which could not be resolved. This result indicated the polyphyletic group of Cycas sections. Base substitution patterns further revealed that the subsection Rumphiae of the section Cycas could be separated into two groups (C. rumphii and C. edentata). In addition, the high bootstrap demonstrated that C. taitungensis was closely related to C. revotuta, while two other species of the section Wadeanae (C. wadei and C. curranii) were closely related, which agreed with the morphology. Data analyses suggested that the trnS-trnG sequences were more informative than the psbM-trnD and trnL-trnF regions in addressing phylogeny. Short and moderate repeated sequences detected in this region also indicated the high rate of evolution in the Cycas species. The 14 bp tandem repeats identified in this study are the first to be reported on the non-coding chloroplast DNA of Cycas. |
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