透過您的圖書館登入
IP:3.237.65.102
  • 期刊

針對稻熱病Pia及Piz基因座分子輔助選育秈稻新品系之研究

Study on Development of Indica Breeding Lines Introgressed Blast Gene for Pia and Piz Loci through Marker-Assisted Backcross Approach

摘要


稻熱病會嚴重影響稻榖品質與產量,一直係台灣稻作栽培的重要病害之一。為有效提高新品系抗性,本研究以秈稻高產品種「台中秈17號」為輪迴親,美國稉型稻抗病品種'Zenith'為提供親,利用分子標誌輔助回交法,將'Zenith'所帶抗稻熱病Pia及Piz的allele(對偶基因)導入「台中秈17號」之中,評估最佳抗性組合。在選育期間,每個回交世代均進行前景選拔,檢出帶2個'Zenith'抗病alleles之植株;並自BC_2F_1世代開始,以前景選拔之獲選植株為對象進行遺傳背景選拔,最後於2015年第1期作選出平均遺傳背景回復率達92%以上,帶1或2個抗病基因之同質結合植株(BC_3F_2)共14個株系,並給予品系名稱CNY1042052-CNY1042065。這14個品系與「台中秈17號」於2015-2016年進行旱田病圃葉稻熱病檢定及產量比較試驗,結果發現帶有'Zenith'的Pia allele並保有「台中秈17號」的Piz allele者的抗性最佳,例如CNY1042052(罹病平均等級4)、CNY1042056(罹病平均等級2)及CNY1042057(罹病平均等級1.5)表現抗-中抗級(R-MR)反應,優於兩親本之中抗-中感級(MR-MS)反應;亦定序兩親本Piz基因序列後,發現「台中秈17號」的Piz基因序列與其他已知品種的Piz基因序列相異。產量試驗上,14個品系之平均產量均低於「台中秈17號」,新品系間以品系CNY1042052之產量表現最高(5,390.0 kg ha^(-1)),表現其次為CNY1042057(5,280.0 kg ha^(-1));綜合評估下,而以品系CNY1042057在抗病性及產量方面皆有不錯的表現。本研究已將抗病對偶基因順利導入「台中秈17號」,惟新品系之產量稍低,藉由各產量構成要素與產量的相關性分析,發現決定新品系產量高低之因素主要為穗數,其次為稔實率,與輪迴親之穗重型特徵有所不同,未來將調整新品系的灌溉施肥等栽培方式,抑制過度分蘗、增大穗型,有助改善抗性品系的產量表現。

並列摘要


Rice blast is one of severe diseases in Taiwan resulting in the loss of grain yield and quality. In this study, novel breeding lines with a single or two blast resistant genes (R gene) were developed by incorporating blast resistance genes (Pia and Piz) from a japonica donor 'Zenith' into elite indica cultivar 'Taichung Sen 17' ('TCS17') based on marker-assisted backcrossing (MABC) strategy. The foreground selection was conducted for the blast resistant genes (Pia and Piz) during the period from BC_1F_1 to BC_3F_2. The background selection, containing 77 InDel and 25 SSR markers, was executed from BC_2F_1 to BC_3F_2 generations. In the first cropping season of 2015, 14 breeding lines with a single or two R genes were selected with a high background recovery rate (> 92%). Based on the results of blast screening trials in 2015 and 2016, breeding lines CNY1042052, CNY1042056 and CNY1042057 with the Pia gene of 'Zenith' allele and the Piz gene of 'TCS17' allele showed lower severity scale (4, 2 and 1.5, respectively). The sequencing result of both parents in the Piz locus exhibited that 'TCS17' has a novel Piz allele. In the yield trial, the grain yield of all novel breeding lines were lower than the recurrent parent 'TCS17.' Among 14 lines, the best performance of grain yield was CNY1042052 (5,390 kg ha^(-1)) and the second highest was CNY1042057 (5,280 kg ha^(-1)). Based on the evaluation of disease resistance and yield performance, the novel breeding line CNY1042057 possessed the best yield potential and strongest resistance. The correlation analysis between grain yield and yield com ponents of the 14 backcross lines suggested that the limiting factors were panicle number and spikelet fertility. In future, the cultivation strategy (irrigation or fertilizer application) will focus on the control of panicle numbers to increase the grain yield of the novel resistant lines.

延伸閱讀