水稻抗白葉枯病之分子標誌輔助育種

Marker-Assisted Selection for Bacterial Blight Resistant Lines of Rice

張瑞炘(Ray-Shin Chang) ； 楊嘉凌(Jia-Ling Yang) ； 許志聖(Chih-Sheng Sheu)

《臺中區農業改良場研究彙報》 110期 (2011/03) Pp. 55-70

https://doi.org/10.6956/BTDAIS.201103.0055

摘要

白葉枯病是國內水稻重要的細菌性傳染病，由Xanthomonas oryzae pv. oryzae感染所引起，為控制此傳染病之危害，目前研究已發現30個以上的抗病基因，國際水稻研究所並育成以IR24品系為遺傳背景且帶有各種抗病基因的近同源系，IRBB66為其中之一。本試驗分別以臺中秈10號與臺稉9號為母本，抗白葉枯病品系IRBB66為父本進行雜交，雜交後裔之F2族群各有256單株，分別以STS、SSR與CAPS等分子標誌針對xa5、Xa7及Xa21等抗病基因進行檢測。檢測結果顯示，試驗中所使用的分子標誌皆具有可區分而易判別之多型性，在臺中秈10號× IRBB66之F2族群中，xa5、Xa7及Xa21等3個抗病基因連鎖之同質 結合分子標誌基因型個體分別佔27.95％、20.88％及24.08％；而在臺稉9號× IRBB66之F2族群中，xa5、Xa7及Xa21的抗病基因連鎖之分子標誌同質結合基因型個體分別佔25.0％、18.95％及24.28％。各基因型之分佈，大部分皆符合孟德爾遺傳分離律之比例，唯有Xa7基因在臺稉9號× IRBB66之F2族群有分離偏差之現象。本試驗獲得的抗病基因之遺傳行為資訊，有助於未來擬定正確的育種策略，且試驗採用的分子標誌輔助育種試驗模式，提供比傳統抗病性狀調查更明確的選種依據，有助於縮短育種年限，對未來的育種研究工作有良好的應用價值。

關鍵字

水稻白葉枯病 ； 分子標誌輔助育種

並列摘要

Rice bacterial blight caused by Xanthomonas oryzae pv. oryzae. is an important rice infectious disease in Taiwan. More than 30 bacterial blight resistance genes have been discovered during the past few decades. The International Rice Research Institute (IRRI) has successfuly bred several near isogenic lines with the IR24 genetic background that contain different bacterial blight resistance genes. IRBB66 is one of them. The present study reveals the distribution of xa5, Xa7, and Xa21 genes in the F2 populations derived from the two corsses of Tai-Ken 9 × IRBB66 and Taichung-Shien 10 × IRBB66. The three genes were dectected by closely linked molecular markers blonging to STS, SSR, and CAPS types. The results show that the above molecular markers worked efficient discrimination of various genotypes in progenies. The proportion of homozygous resistant genotypes of xa5, Xa7, and Xa21 loci are 27.95%, 20.88%, and 24.08% respectively in the F2 population of TCS10 × IRBB66. On the other hand, the proportion of homozygous resistant genotypes of xa5, Xa7, and Xa21 loci are 25.0%, 18.95%, and 24.28% respectively in the F2 population of TK9 × IRBB66. The distributions of most examined genotypes are following Mendel’s segregation law except Xa7 locus in the F2 population of TK9 × IRBB66, which showing bias distritubion. The results of our study provide the information of inheritance behaviors of these three resistance genes, and the information will be helpful for the proper strategies design of breeding. Marker-assisted selection (MAS) approach utilized in this study can provide clear and difinite evidences for targeted traits selection. We believe that this strategy can enhance the efficiency and shorten the period of breeding. In general, MAS will be a valuable and practicable model for crop breeding in the future.

並列關鍵字

rice bacterial blight ； Xanthomonas oryzae pv. oryzae ； marker-assisted selection