利用分子標誌輔助回交以改良稻米白堊質性狀

白堊質為影響稻米品質之重要性狀，本研究利用分子標誌輔助回交育種，將水稻品種台南16號的低白堊質相關基因導入台南13號之中，以改良台南13號水稻品種白堊質米粒比例偏高之缺點。首先以台南13號與台南16號雜交族群之160個F_2後代及其56個F2：3品系為材料，利用混合DNA分群分析法篩選與白堊質基因座緊密連鎖之分子標誌，並利用單一分子標誌分析法驗證，共篩選三組與白堊質性狀基因座緊密連鎖之CH0648、CH0463與RM22155分子標誌，及兩組與食味相關性狀基因座緊密連鎖之RM8120與RM14275分子標誌，藉以輔助選拔低白堊質與食味佳之優良品系。經過BC_1F_1、BC_2F_1、BC_3F_1與BC_3F_2世代的前景選拔與背景選拔，共選獲6個優良品系，全部品系之乳白率、腹白率和基白率皆低於親本台南13號，其中#K5-79其白堊質表現幾乎與親本台南16號相同，而#K4-6具有較低之白堊質表現且榖粒較大，為非常有潛力的2個品系。本研究結果亦顯示利用分子標誌輔助轉移多個基因及加速恢復輪迴親遺傳背景之效果。

關鍵字

水稻；白堊質；回交；分子標誌輔助選種；前景選拔；背景選拔

並列摘要

The trait of chalky grain is very important for rice quality. The purpose of this study was to improve rice variety TN13, which has high percentage of chalky grains. Low chalky alleles were introduced from variety TN16 to TN13, with marker-assisted backcross breeding (MAB). A total of 160 F_2 progenies developed from a cross between rice varieties TN13 and TN16, and 56 F_(2:3) lines were used to identify markers associated with grain chalkiness by bulk segregant analysis (BSA), and the associated markers were verified with single marker analysis (SMA). Three markers (CH0463, CH0648 and RM22155) linked with grain chalkiness loci, and two markers (RM14275 and RM8120) linked with eating quality loci were used for selections. Through foreground and background selections of BC_1F_1, BC_2F_1, BC_3F_1 and BC_3F_2 populations, six superior BC_3F_2 derived lines were selected. All of these selected lines had lower milky-white, white-belly and white-base rates than the recurrent parent TN13. K5-79, one of six selected lines, had the least low chalky rate as TN16 (donor parent). Another promising line K4-6 has larger gains with less chalkiness. The study has demonstrated the efficiency of MAB to transfer multiple genes and enhance the genetic background recovery of recurrent parent.

並列關鍵字

Rice ； Chalkiness ； Backcross ； Marker-assisted selection ； Foreground selection ； Background selection

國際替代計量

利用分子標誌輔助回交以改良稻米白堊質性狀

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