Mitochondrial DNA sequence variation among Ceratitis capitata and local fruit flies of quarantine importance and its applications on species identification (Diptera: Tephritidae)

• Main Authors: Tzu-Yu Chen, 陳孜彧
• Other Authors: 蕭旭峰
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/81872656682888964374

碩士 === 國立臺灣大學 === 昆蟲學研究所 === 93 === Pest species in family Tephritidae are considered very important in economical aspect, especially those listed in quarantine pests. Since the damage caused in their endemic areas, the efforts of preventing these species from dispersing are great. The detection of quarantine pests at the harbors and in the field are essential in quarantine works, and the most important job of the detection is the identification of those pest species. Using molecular technique as a method of identifying insect species is easy for routine operation and its standardized procedure and application on all life stages make this method a powerful tool in the detection of quarantine pests. In this study, a major fruit fly species that has not invaded Asia but with high risk of invasion: Ceratitis capitata was chosen to be the material, along with three local tephritid pests: Bactrocera dorsalis, B. cucurbitae and B. tau, which are also the pests of highly economical importance. The aim of this study was to set up a basic molecular database which could be the foundation of designing species identification method and to actually design a simple identification method for the four species. By using PCR-sequencing, a total of 9,260bp mitochondrial DNA sequence data in ten molecular regions were resolved for all of these four species, that is about 3/5 of the total mitochondrial genome. After alignment of all the sequence data, species-specific sites were located. Analysis of the ten sets of sequence data showed that intraspecific sequence identity (98.01%~99.33%) are all higher than that in the interspecific sequences (83.91%~94.31%). And according to the results of phylogenetic analysis, the reconstructed relationships based on the sequence data basically matched that in the classical taxonomy. The species-specific molecular primers designed by sequence variations were also proven to be useful in distinguishing those four species, even under the conditions of the low extracted DNA amount.