 |
 |
 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Novel PCR Primers for Specific Detection of Xanthomonas citri subsp. citri the Causal Agent of Bacterial Citrus Canker) ผู้เขียน: ดร.อุดมศักดิ์ เลิศสุชาตวนิช, ผู้ช่วยศาสตราจารย์ , ดร.อำไพวรรณ ภราดร์นุวัฒน์, รองศาสตราจารย์ , Junlapark Chunwongse, Norman W. Schaad, ดร.นิพนธ์ ทวีชัย, ศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractThe new primers were developed for specific detection of Xanthomonas citri subsp. citri (Hasse) (Xcc) [syn. X. axonopodis pv. citri (Xac)], the causal agent of Asiatic citrus canker disease. Twenty three strains of Xcc and 34 strains of other xanthomonads including X. fuscans subsp. aurantifolii, X. alfalfae subsp. citrumelonis, X. campestris pv. campestris, X. campestris pv. glycines, X. citri subsp. malvacearum and X. fuscans subsp. fuscans were tested for specificity of new primers by classical PCR. The results showed that these 354 F/R primers specifically amplified all of Xcc strains but not other xanthomonad strains. The 354-bp PCR fragment was sequenced and its nucleotide sequences were compared for similarity with Genbank database. The 354-bp nucleotide sequences were 99.7% similar to gene XAC2443 of Xac strain 306 (Accession AE011881). The sensitivity of these specific primers for detection of viable cells and total DNA of Xcc were 70 CFU/?l and 50 pg/?l, respectively. Therefore, these novel primers can be used as an alternative application for rapid and specific detection of Xcc. |
 |
 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Genetic Analysis of Ralstonia solanacearum Strains from Different Hosts in Thailand Using PCR-Restriction Fragment Length Polymorphism) ผู้เขียน: Piyarat Thammakijjawat, ดร.นิพนธ์ ทวีชัย, ศาสตราจารย์ , ดร.วิชัย โฆสิตรัตน, รองศาสตราจารย์ , ดร.จุลภาค คุ้นวงศ์, รองศาสตราจารย์ , Reid D. Frederick, Norman W. Schaad สื่อสิ่งพิมพ์:pdf AbstractGenetic relatedness of 108 strains of Ralstonia solanacearum (RS) from different hosts in Thailand and other countries were assessed by restriction fragment length polymorphism (RFLP) technique using a pair of primers 759f (5’- GTCGCCGTCAACTCACTTTCC -3’) and 760r (5’- GTCGCCGTCAGCAATGCGGAATCG -3’). An amplified DNA fragment of 281 base pairs was obtained from all RS strains and showed three and five patterns after digested with HaeIII and MspI restriction enzymes, respectively. Six RFLP groups were designated A, B, C, D, E and F based on the eight patterns of HaeIII and MspI products. Cluster analysis by UPGMA with Dice’s coefficient divided into two clusters at 13% similarity. Cluster I contained group A (biovar 1/race 1), group B (biovar 2/race 3) and group C (biovar 1/race 1 and race 2) while cluster II consisted of group D (biovars 3, 4/race1, biovar N2 and the blood disease bacterium, BDB), group E (biovar 1/race 1) and group F (biovars 1, 3, 4/race 1 and biovar 5/race 5). RS strains of Thailand were mainly typed into race 1 biovars 3 and 4 and few strains were race 3 biovar 2 from potato in the highland. The strains of race 1 biovar 3 from Thailand could be separated into two groups (D and F) in which group D consisting of strains from pepper, tomato and marigold and group F containing only strains from sesame. The strains of race 1 biovar 4 from ginger and patumma, and race 3 biovar 2 from potato were designated into group D and B, respectively. Comparing with foreign strains, most of biovar 3 and all of biovar 4 from Thailand shared with the strains of biovars 3 and 4 from other countries, biovar N2 strains from Japan including the BDB from Indonesia except biovar 3 of sesame strains which comprised with strains of biovars 1, 4 and 5 from other countries, while biovar 2 strain from highland potato grouped together with the potato strain from other countries. In addition, this technique demonstrated a rapid and efficient identification strains of RS biovars 3, 4 and N2 from biovars 1, 2 and 5 within approximately 6 hr and provided a similar result of RFLP analysis with hrp probe encoded for hypersensitive response and pathogenicity which consumed times and expenses. |
 |
 |