農業部-水產試驗所全球資訊網農業部-水產試驗所全球資訊網

   本所已建立的耐低溫紅色吳郭魚TsR品系，但成長和體型不如市面上尼羅品種 ，因此，為改良吳郭魚的低溫適應能力，本研究以耐低溫紅色吳郭魚TsR品系和尼羅 系統的尼羅n561A品系作為親本，逐代建立正反雜交F1，自交F2和回交BC1F1觀察這些 後代在低溫適應之分離比，從F 2群以所設定的降溫模式利用逢機幅多型性 DNA（Randomly Amplified Polymorphic DNA ; RAPD）對倖存者和犠牲者間基因差 異，推測低溫適應可能的遺傳機制並選殖關聯的基因標誌。為選殖該關聯等位基因 標誌，利用80個指紋分析找出具有多型性之RAPD基因座，分別轉成序列特徵增幅區 域（Sequence Characterized Amplified Region；SCAR）基因座，利用尼羅 n561A品系之全基因組框架定位所選殖的SCAR標誌，預計本研究可建立F2作為低溫適 應的基因標誌選殖、優化和聯鎖的定位，以提高篩選率效及育種時程。

    In this study, we have bred a low-temperature-tolerant red tilapia TsR strain, but its growth and body size are not as good as the Nile species. To improve the low-temperature adaptability of Nile tilapia, we crossed TsR with n561A to establish F1, F2, and first backcross n561A for low-temperature resistance. These F2 crossed offspring were treated by cooling mode and collected survivors and victims respectively. then use Randomly Amplified Polymorphic DNA (RAPD) to genotype the genetic variation. To assess possible genetic mechanisms and low temperature of adaptation, we use 80 RAPD loci to fingerprint and clone the markers associated with the cold-tolerance. Then use the whole genome framework of Nile n561A strain to locate the marker selected Sequence Characterized Amplified Region (SCAR). Finally, we bred F2 which with low temperature resistant, cold-resistant associated gene marker and cloning, optimization, and positioning interlocked improve screening efficiency and shorten breeding.