分子標誌輔助水稻台稉9號之抗白葉枯病回交育種

Marker-Assisted Backcrossing for Introgressing Rice Bacterial Blight Resistance Genes to the Variety Taikeng 9

張瑞炘(Ray Jui-Hsin Chang) ； 鄭佳綺(Chia-Chi Cheng) ； 楊嘉凌(Jia-Ling Yang) ； 郭建志(Chien-Chih Kuo)

《臺中區農業改良場研究彙報》 133期 (2016/12) Pp. 33-46

摘要

水稻台稉9號為國內重要良質米品種，米粒品質優良但缺少抗白葉枯病基因，栽培期間可能因白葉枯病而影響產量，如何防治此病害成為重要課題，最經濟之作法為育成抗病品種，本場採用國際水稻研究所育成之IRBB66品系為貢獻親並以台稉9號為輪迴親進行回交育種，每一世代皆檢測Xa4、xa5、Xa7、xa13與Xa21等5個基因之分子標誌以輔助選拔，已完成繁殖BC_3F_2分離族群計1,000株。本試驗運用分子標誌檢測1,000株BC_3F_2個體，共選拔獲得9株帶有5個抗病基因之個體，其中1株帶有5個同質結合基因。獲選9株個體於分蘗盛期採用白葉枯病菌株接種，接種之結果皆未出現超過10公分之病斑。在遺傳背景分析方面採用限制酶切位標定片段定序法，完成SNP之探勘與比對，遺傳背景分析結果顯示9株個體回復率與台稉9號之相似度都超過80%，其中6株超過85%，在全基因組同質結合率方面9株個體皆超過92%，其中第2、4、7、9、10、11、12號染色體，每株個體同質結合率皆超過99%，本次試驗所選拔之9株個體，各帶有3-5個抗病基因，未來可建立9個家系，進而累積自交世代育成抗病品種。

關鍵字

水稻白葉枯病 ； 水稻白葉枯病菌 ； 分子標誌輔助育種 ； 回復率 ； 前景選拔

並列摘要

Rice variety Taikeng 9 is one of the most important high-quality cultivars in Taiwan. It obtained excellent palatability but senstive to rice bacterial blight (Xanthomans oryzae pv. oryzae). Yield loss could happen when bacterial blight outbreaks. To breed resistant varieties is the most economic way to prevent the disease. This study conducted a backcross breeding by utilizing IRBB66 from IRRI as the donor parent and Taikeng 9 as the recurent parent. Every generation from F1 to BC_3F_2, the selection was based on detecting the five bacterial blight resistance genes, Xa4, xa5, Xa7, xa13, and Xa21. Screeing on BC_3F_2 population, 9 out of 1,000 individuals were verified and selected carrying 3-5 R genes. One of the 9 individuals contain 5 homozygous R genes. The 9 individuals was inoculated by X. oryzae pv. oryzae and none of their leaf lesions longer than 10 cm. The genetic backgrounds were analyzed by restriction site-associated DNA sequencing, and SNPs in their genomes were discovered and genotyped. The genetic backgrounds showed the 9 individuals all have recovery rates higher than 80%, and 6 of them were higher than 85%. The homozygosity of the 9 individuals are all higher than 92%. On chromosomes 2, 4, 7, 9, 10, and 12, the average homozygosity were higher than 99% among 9 individuals. The 9 selected individuals with 3-5 R genes could establish 9 familieswhich is valuable breeding reources for bacterial blight resistant rice varieties.

並列關鍵字

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