水稻良種繁殖圃中異型株之遺傳分析

Genetic Analysis of Off-Type Plants of Rice in the Three-Step Propagation Nursery

吳東鴻(Dong-Hong Wu) ； 胡凱康(Kae-Kang Hwu)

《台灣農業研究》 60卷3期 (2011/09) Pp. 197-210

https://doi.org/10.6156/JTAR/2011.06003.05

摘要

本研究的目的為探討水稻良種繁殖異型株之可能形成因子；以對於2004至2005年台灣地區良質米水稻品種具有完全鑑別力之23個SSR標誌為分析工具，而各品種遺傳組成之標準資料，係以2004年第2期作良種繁殖更新計畫中所生產之原原種種子為基礎。本試驗從29處繁殖圃共取得40件田間異型株，其結果顯示共有8件與對照樣品相同基因型、8件品種內分離基因型、6件品種混雜、13件天然雜交後裔與5件未知品種。顯見大部分田間異型株主要係因天然雜交、品種混雜或品種內均一性不足所致；為了提高良種繁殖制度之效益，建議各級繁殖圃應加強執行設置保護行避免外來花粉汙染，並進行單株選拔提高品種均一性，收穫前確實田間去偽去雜清除異品種混雜等作業。

關鍵字

水稻 ； 三級繁殖圃 ； 異型株 ； 簡單重複序列標誌

並列摘要

The objective of this study was to determine the genetic composition of 40 off-type plants of rice (Oryza sativa) from 29 sampling locations in the three-step propagation nursery. Twenty-three simple sequence repeat (SSR) markers capable of identifying the 22 superior rice varieties produced in Taiwan in 2004 and 2005 were used in this study. Foundation seeds from the second crop of 2004 were used to establish standard genetic profile of the 22 rice varieties. Results of allelic composition analyses showed that, among the 40 rice off-type plants tested, 8 cases were identical to the standard genotype profile, 8 cases were other genotypes within variety, 6 cases were variety mixture, 13 cases were hybrid progeny and 5 cases were unknown variety. These results suggest that the off-type plants of rice were mostly originated from natural hybridization, mixture of varieties and low genetic uniformity within variety. In order to improve efficiency of the three-step propagation nursery for production of superior rice varieties with genetic purity, it is necessary to establish guard rows in the field to prevent outcrossing by foreign pollen, conduct one more generation for single plant selection during breeding programe and rogue out off-type plants and foreign variety from seed producing nurseries.

並列關鍵字

Rice ； Oryza sativa ； Three-step propagation nursery ； Off-type plant ； Simple sequence repeat