2007-01-012024-05-14https://scholars.lib.ntu.edu.tw/handle/123456789/661033摘要：本計畫擬針對台灣梨衰弱病PDTW病原菌質體進行分子檢測實驗，監控媒介昆蟲中國梨木蝨之擴散範圍，與其造成其他梨樹栽培區域感染此系統性病害之情況，並釐清第十群（PDTW）與第二群（PDTWII）植物菌質體對罹病植株之感染情形，進一步調查這兩群植物菌質體單一及複合感染之病徵發展；此外，藉由監測田間中國梨木蝨在各地梨園之發生，可加以檢測其是否帶菌與傳播此兩群梨衰弱病菌質體之情形。目前中國梨木蝨在全台梨園逐漸遷徙蔓延，需持續定期監控此傳染性病害之發生，以於病害發生初始階段，得以採取適當的防治措施。希冀藉由上述研究並配合往年計畫中台灣梨樹衰弱病之研究成果，擬定台灣梨衰弱病防範傳播之策略。<br> Abstract: In 1994, pears with decline symptoms similar to the slow decline form of pear decline (pear decline-Taiwan, PDTW) were observed in orchards of Asian pear (Pyrus pyrifolia (Burm. f.) Nakai) in Dungshr and Heping. PCR that can specifically amplify the conserved 16S rDNA sequence of PDTW phytoplasma was conducted to detect the presence of PDTW phytoplasma in plants and vectors. According to the analyses of the 16S rDNA and 16S-23S rDNA spacer sequence, the PD-like disease was confirmed to be caused by phytoplasma closely related to those of the apple proliferation group. In this work, PCR was also applied in the study of vectorship. On the basis of rDNA sequence of PDTW phytoplasma, two specific primer pairs APf2/ L1n and APf3/ rPD1s were designed for the detection of the agent in insect vector. Two species of pear psyllas Cacopsylls qianli and C. chinensis were discovered in 1994 and 2002, respectively. PCR-based detection was applied in the study of vectorship and the result implied C. qianli is a candidate of the vector of PDTW. Pear decline phytoplasma was observed in pear leaf vein and two insect vectors by transmission electron microscopy. Based on the sequence analyses, phytoplasmas of two different 16S rDNA groups, 16SrII and 16SrX, were revealed to be associated with PDTW-affected pear trees and carried by C. chinensis. Specific primers IIPf1/ IIPr1 along with IIPf2/ IIPr1 for PDTWII phytoplasma, and primers fPD2/ rPDs1 along with APf3/ rPDs1 for PDTW phytoplasma had been applied in semi-nested PCR. The 16S rDNA sequences of PDTW and PDTWII phytoplasmas were amplified by PCR from genomic DNA of Cacopsylla chinensis in Jianshih, Hsinchu county. The pear trees in Jianshih began to show the symptom of redden leaves in 2006. 16S rDNA sequences of PDTW and PDTWII phytoplasmas were amplified with PCR from genomic DNA of diseased pear tree in Jianshih and were identical to those sequences obtained from the phytoplasmas carried by C. chinensis.梨衰弱病植物菌質體聚合酵素連鎖反應媒介昆蟲中國梨木蝨黔梨木蝨穿透式電子顯微鏡pear declinephytoplasmapolymerase chain reactionPCRinsect vectorCacopsylla chinensisCacopsylla qianlitransmission electron microscopy