以功能性分子標誌輔助回交策略選育具低鎘累積能力之秈稻新品系

A Novel Indica Rice Breeding Line Selection with Low Cadmium Accumulation Level by Functional Markers Assisted Backcross Strategy

吳佩真(Pi-Jen Wu) ； 林毓雯(Yu-Wen Lin) ； 李長沛(Charng-Pei Li) ； 許健輝(Chien-Hui Syu) ； 卓緯玄(Woei-Shyuan Jwo) ； 顏信沐(Hsing-Mu Yen) ； 郭鴻裕(Horng-Yuh Guo) ； 賴明信(Ming-Hsin Lai) ； 吳東鴻(Dong-Hong Wu)

《台灣農業研究》 66卷3期 (2017/09) Pp. 248-260

https://doi.org/10.6156/JTAR/2017.06603.08

摘要

本研究將運用分子輔助回交技術，將稉稻具有降低鎘累積量的遺傳組成置換至秈稻品種中，藉此改良秈稻品種的遺傳組成。而研究策略則先運用功能性標誌篩檢國內栽培品種對於鎘吸收的遺傳特性，再利用分子輔助選種技術選育1個具有低累積性的秈稻新品系，最後直接在高風險區進行現地評估與品系驗證試驗。首先，建立根吸收(OsNRAMP1)主效基因座的功能性標誌，確認國內推薦秈稻品種均帶有鎘易吸收基因型，與過去已知秈稻較稉稻品種更易吸收轉運土壤中鎘物質之現象相符。隨之，利用分子輔助回交育種法，從前期研究(2006-2011)所選育「台中秈10號」全染色體置換系中，挑出適當品系由2014年第1期作開始，選育出帶有低鎘累積特性的秈稻新品系。2015年第1期作在后里試驗區進行現地評估，可知秈稻新品系台中秈10號qCdT7帶有低累積基因型，與「台中秈10號」有高度相似株型，但大幅下降鎘累積程度達42.2%，能有效降低秈稻品種易發生鎘米風險的困擾。總結，本試驗運用分子輔助回交策略改良國內秈稻栽培品種後，並於現地栽培環境下進行初步可行性評估，冀望新品系選育能兼具在稻作生產與食品安全上提供一項緩解措施。

關鍵字

鎘累積量 ； 田間試驗 ； 功能性標誌 ； 秈稻 ； 分子輔助回交

並列摘要

The goal of this study was to improve the genetic uptake factor in indica rice cultivars through introgression of a japonica DNA segment that limits Cd accumulation. Our strategy was to screen the genetic potential of Cd uptake in Taiwan cultivars using a functional marker, develop a novel indica line by marker-assisted selection, and then evaluate the genetic improvement of the target breeding line under field conditions. Genotyping with the functional marker of OsNRAMP1 showed that the current Taiwan indica cultivars possessed a high accumulation allele that was consentient with the phenotype of the Cd accumulation trend between Taiwan indica and japonica cultivars. Subsequently, we selected advanced backcross inbred lines (BC4F2) from a chromosome 7 segment substitution line population that was derived from the cross between ‘Taichung Sen 10 (TCS10)’ and ‘Taikeng 2’ based on previous studies (2006–2011). An indica line, TCS10-qCdT7, that limits Cd accumulation was developed in the first cropping season of 2014 and possessed 96% genetic background similarity compared with the recurrent parent ‘TCS10’. In the first cropping season of 2015, this new breeding line exhibited the highly similar morphological characteristics compared with the indica variety ‘TCS10’, but had a Cd bio concentration factor in brown rice that was 44.4% less than that in the ‘TCS10’ parent. In summary, this study was conducted in a field environment and improved one of Taiwan’s popular indica cultivars using a marker-assisted backcross approach. The newly developed lines in this study would have the potential to contribute greatly to the future cultivation of rice production and increase the food safety within the Taiwan rice industry.

並列關鍵字

Cadmium accumulation ； Field trial ； Functional marker ； Indica rice ； Marker assisted backcross selection