2015-01-012024-05-15https://scholars.lib.ntu.edu.tw/handle/123456789/662904摘要：稻熱病可發生於水稻各個生育時期，在全球造成相當程度之經濟損失。為因應近年來稻熱病好發問題，持續選育本土水稻抗性品系並適當推廣種植，應為較經濟有效之防治措施。過往針對稻熱病進行品種改良時，常因傳統育種方法耗時，難以因應稻熱病菌族群 Avr genes 之快速演化，同時水稻雖已有被定序之20個抗性R genes，不同品系的同一個抗性基因座卻極可能存在相當複雜的基因多型性。本計畫將以帶有單一已知 R gene之IRBL判別品種為抗性貢獻親本，具代表性之本土良質米品種高雄145為導入對象，建立一套適用於稻熱病抗性育種之分子標誌與技術平台。本年度研究重點包括：(1) 以前一年新開發之分子標誌，針對不同組合「IRBL x 高雄145」之大量 BC1F1、BC2F1 個體，進行前景 R genes 與遺傳背景之檢定，並搭配人工接種試驗，篩選出抗病植株與良質米高雄145回交產生BC3F1。(2) 針對Pi2/Pi9、Pik與Pita loci繼續進行序列分析，另將搜尋IRBLs中其他具潛力之稻熱病抗性基因座，開發與 R genes 緊密連鎖之分子標誌，並探討國內重要良質米品種所缺乏之R genes，逐步強化稻熱病分子育種平台。<br> Abstract: Rice blast pathogen can infect rice plants at all growth stages, causing severe economic damage all around the world. Breeding and deployment of blast resistance cultivars is one of the most economical, effective, and eco-friendly way to control the disease. Conventional breeding approaches take long time to develop a new variety. However the new variety can be overcome within 2-3 years by fast-evolving M. oryzae population in the field. Although 20 resistance (R) genes have been cloned to date, the sequences and complex genetic structures of the R gene alleles in Taiwan cultivars remain unknown. This study aims to set up a marker-based blast resistance breeding platform, which will facilitate the marker-assisted introduction of known R genes from IRBL monogenic differential lines into a high-quality rice cultivar “Kaohsiung 145”. This year we plan to focus on: (1) Application of the newly-developed molecular markers for foreground (R genes) and background genotyping of the BC1F1 and BC2F2 individuals from various cross combinations of“IRBL x Kaohsiung 145”. The genotypes, together with the resistance phenotypes from artificial inoculation tests, will be used for identification of resistant progenies, which will be backcrossed with Kaohsiung 145 to generate BC3F1. (2) We will continue the sequence analyses of Pi2/Pi9, Pik, and Pita loci, and work to develop more molecular markers targeting other potentially effective R gene loci in IRBLs. To strengthen the breeding platform, the possession or absence of targeted R genes in high quality rice cultivars will also be studied.稻熱病菌IRBL 單基因判別品種分子標誌輔助回交育種Magnaporthe oryzaeIRBL monogenic linesmarker-assisted backcrossing