使用回交近同源系研究番茄花粉耐熱特性之數量性狀基因座

Abstract

由於全球暖化日漸加劇，氣溫的上升會造成番茄的產量下降，而番茄花粉活性為決定產量的關鍵因素之一。本研究利用分子標誌輔助回交選育（MABC）策略，以熱敏感品系CA4為貢獻親、耐熱品系CLN1621L為輪迴親，構築近同源系（NILs）對實驗室先前定位之花粉活性數量性狀基因座（QTLs）PV03與PV10進行研究。透過兩階段分子標誌輔助選育，精確篩選出目標QTL滲入片段，並結合ddRAD-seq技術加速輪迴親遺傳背景的恢復。在BC2F2世代，成功分離出CLN1621L背景下帶有不同目標滲入片段的四組近同源系：CLN1621L(WT)、CLN1621L-IL3.0_Chr3(54.09-54.78Mb)、CLN1621L-IL3.0_Chr10(3.00-57.35Mb)及結合兩者的雙滲入系CLN1621L-dIL3.0_Chr3+10(Combined)。透過螢光染色法（FDA與PI）與影像分析技術，評估在高溫環境下各近同源系之花粉活性表現。結果顯示，所有四個近同源系的花粉活性均高於貢獻親CA4。然而，所有NILs的花粉活性與輪迴親CLN1621L相比，均無統計學意義上的顯著差異。需要於溫度控制更為精確的環境下再進行表現型試驗來驗證這個結論。

Global warming has led to rising temperatures, causing significant declines in tomato yields, with pollen viability being a critical factor in determining productivity. This study examined previously identified quantitative trait loci (QTLs) for pollen viability, PV03 and PV10, by constructing near-isogenic lines (NILs) through marker-assisted backcrossing (MABC), using the heat-sensitive line CA4 as the donor and heat-tolerant CLN1621L as the recurrent parent. Following two-stage marker selection and ddRAD-seq-assisted background recovery, four NIL groups were isolated in the BC2F2 generation:CLN1621L(WT), CLN1621L-IL3.0_Chr3(54.09–54.77Mb), CLN1621L-IL3.0_Chr10(3.00–54.78Mb), and CLN1621L-dIL3.0_Chr3+10(Combined). The pollen viability performance of each near-isogenic line under high-temperature conditions was evaluated using fluorescence staining (FDA and PI) and image analysis techniques. Results indicated that all four NILs had higher pollen viability than the donor parent, CA4. However, all NILs showed no statistically significant differences in pollen viability compared with the recurrent parent CLN1621L. Further phenotypic trials under precise temperature control are required to validate this conclusion.