應用於臺灣良質米品種改良之抗稻熱病基因座分析與分子標誌開發

Analysis of blast resistance genes and molecular markers development for the improvement of Taiwan high-quality rice varieties

陳韋綸(W. L. Chen) ； 沈偉強(W. C. Shen) ； 張芳瑜(F. Y. Chang) ； 張為斌(W. B. Chang) ； 余宗學(T. H. Yu) ； 賴明信(M. H. Lai) ； 廖睿瑜(J. Y. Liao) ； 吳志文(C. W. Wu) ； 鍾嘉綾(C. L. Chung)

《植物病理學會刊》 24卷3&4期 (2015/12) Pp. 225-240

https://doi.org/10.6649/PPB.201512_24(3_4).0005

摘要

Magnaporthe oryzae引起之水稻稻熱病，於全球產區均造成相當危害。有關稻熱病之防治，使用抗病品種被認為是有效、經濟且環保的方式，而新興的分子標誌輔助選拔（marker-assisted selection, MAS）則可以大幅縮短品種選育的時程。本研究首先針對自國際水稻研究中心引進已知帶有抗性基因的31個IRRI-bred blast-resistant lines（IRBLs），以2009-2013年蒐集自雲林、嘉義、臺南、屏東、花蓮、臺東等6個地區的18株稻熱病菌菌株進行接種，發現位於Pi2/9、Pik、Pita/Pita-2基因座上的抗性等位基因對較多菌株呈現抗病性。接著對抗幅較廣之13個IRBLs及20個臺灣良質米品種，建立一套共11對R gene分子標誌，包括蒐集前人所開發之分子標誌進行多型性測試篩選，及自行運用genotyping-by-sequencing（GBS）定序資料新設計分子標誌等。為了瞭解13個目標抗性等位基因中，哪些適合導入良質米品種，以12YL-TT4-1及13TN-HB1-3兩菌株分別接種13個IRBLs及良質米品種來加以鑑別；結果顯示，台稉4號、台稉9 號、台稉10號、台稉1 號、台稉15號、台農71號、桃園3號、台南11號、高雄145號、高雄147號等10個品種對兩菌株均呈現感病，表示不帶有Pi9（IRBL9-W）、Piz5（IRBLz5-CA、IRBLz5-CA(R)）、Piz（IRBLz-Fu）、Pi1（IRBL1-CL）、Pi7（IRBL7-M）、Pik（IRBLk-Ka）、Pik-p（IRBLkp-K60）、Pikm（IRBLkm-Ts）、Pik-h（IRBLkh-K3）、Pi20（IRBL20-IR24）及Pita-2（IRBLta2-Pi、IRBLta2-Re）等抗性等位基因，故未來適合以13個IRBLs及本研究所開發之多型性分子標誌進行抗性改良。以GBS分析所得之131,942 個SNPs檢視13 個目標IRBLs之遺傳背景，發現來自抗性貢獻親之基因型所佔比例為5.8-65.2%，故IRBL之抗性表現可能同時包含來自抗性貢獻親之R gene及其他遺傳背景效應。

關鍵字

分子標誌輔助選拔 ； 抗病基因分子標誌

並列摘要

Rice blast, caused by Magnaporthe oryzae, is a destructive disease of rice worldwide. Use of resistant varieties is considered an effective, economical, and eco-friendly method for blast control, and the emerging marker-assisted selection (MAS) approach can significantly reduce the time needed for the development of new resistant varieties. In this study, 31 IRRI-bred blast-resistant lines (IRBLs) carrying known resistance (R) genes were inoculated with 18 M. oryzae isolates collected from six geographical areas (including Yunlin, Chiayi, Tainan, Pingtung, Hualien, and Taitung) in Taiwan in 2009-2013. The R alleles at Pi2/9, Pik, and Pita/Pita-2 loci showed resistance to more isolates under tests. Thirteen IRBLs with broader-spectrum resistance and 20 Taiwan high-quality rice varieties were selected as the targets for marker development. We surveyed literatures for previously developed markers and designed new markers based on the sequences acquired using genotyping-by-sequencing (GBS) technique. A set of 11 polymorphic R gene markers were successfully developed. To determine which of the 13 R alleles are suitable for introgression into the highquality rice varieties, two M. oryzae isolates 12YL-TT4-1 and 13TN-HB1-3 were inoculated to assess the differential characteristics of the 13 IRBLs and 20 high-quality rice varieties. Ten varieties, including Taikeng 4, Taikeng 9, Taikeng 10, Taikeng 14, Taikeng 15, Tainung 71, Taiyuan 3, Tainan 11, Kaohsiung 145, and Kaohsiung 147, were compatible to both 12YL-TT4-1 and 13TN-HB1-3 isolates, indicating that they do not carry R alleles at Pi9 (IRBL9-W), Piz5 (IRBLz5-CA, IRBLz5-CA (R)), Piz (IRBLz-Fu), Pi1 (IRBL1-CL), Pi7 (IRBL7-M), Pik (IRBLk-Ka), Pik-p (IRBLkp-K60), Pik-m (IRBLkm-Ts), Pik-h (IRBLkh-K3), Pi20 (IRBL20-IR24), and Pita-2 (IRBLta2-Pi, IRBLta2-Re). Therefore, the 13 IRBLs and newly developed markers can be used to improve blast resistance of the 10 high-quality rice varieties. With 131,942 SNPs resulted from the GBS analysis, the 13 IRBLs were found to contain 5.8-65.2% of the genotypes from their resistance donors. This suggests that the resistance performance of each IRBL may be contributed by not only the R gene but also some genetic background effect from the donor variety.

並列關鍵字

Magnaporthe oryzae ； IRBL ； Marker-assisted selection (MAS) ； Genotyping-by-sequencing (GBS) ； R gene markers