摘要：柑橘萎縮病毒(Citrus tristeza virus = CTV)是柑橘生產上極重要的限制因子，全世界的柑橘都普遍受其危害，導致植株壽命縮短、生長受阻，且造成柑橘果實品質下降，影響產業甚鉅。由於病毒病害無法以藥劑進行防治，得病之後除了將病株砍除之外，實在難覓其他防治良方。台灣雖已有柑橘健康種苗之推展，但田間再感染率極高，常因此降低農民使用健康種苗之意願。本計畫擬以傳統的「交叉保護」學理為基礎，融入先進的生物技術與分生策略，針對CTV嘗試從自然界中篩選獲得弱毒系統，先行接種至健康柑橘幼苗中，使其在定植於田間之後可預防強毒系統之入侵。本年度擬執行的工作項目有：1. CTV檢測技術盤點與補強；2. 全國各重要柑橘產區的CTV採樣； 3. CTV的接種試驗與初步的系統鑑別；4. 具交叉保護潛力之弱毒系統之篩選；5. 溫室內的挑戰接種的試驗。由於CTV在台灣皆有厚實的學術研究基礎，加上交叉保護在國外皆有成功之案例，本計畫之預期成果應可順利達成。
Abstract: Citrus tristeza virus (CTV) is an important limiting factor to the citrus industry in the world. It causes citrus hosts tremendous impacts such as shortening of the lifespan, stunting and poor fruit quality. No available pesticide could be used in the control of plant virus diseases, and elimination of the infected plants was usually taken for the only suggested measure of control. The pathogen-free nursery system of citrus has been promoted in Taiwan. However, these healthy citrus seedlings have high percentages of re-infection by CTV in the field through insect vectors. This project is dedicated to apply the “cross protection” theory to the control of CTV in Taiwan demonstrated by various biotechnologies and the other molecular techniques. The mild strains of CTV will be collected and selected from citrus orchards. The pathogen-free seedlings of citrus will be inoculated with a mild strain of CTV before they are planted in the field, which is expected to show the“cross protection” effect against the infection of severe strains of CTV. Several research items will be proposed in the first year for this project: (1) inventory and improvement of various techniques for CTV detection; (2) collection of CTV isolates from different areas in Taiwan; (3) inoculation tests and strain-categorization of CTV; (4) selection of mild strains with potential for cross protection; (5) challenge tests with severe strains in a green house. Based on the good researches associated with CTV in Taiwan and foreign successful cases in the cross protection of CTV, all expected results in this project should be achieved during the conducted years.
Citrus tristeza virus