評估耐旱相關 QTL 導入水稻台南 11 及台稉14對生理、水分利用之影響

Abstract

全球氣候變遷導致乾旱事件頻繁，對許多重要糧食作物的生長及產量帶來嚴重威脅。如何提高水稻的水分利用效率，並能夠維持足夠的水稻產量則為重要之議題。過去許多與乾旱產量相關的數量性狀基因座 (qDTYs) 之研究顯示，在乾旱情況下，能夠有一定的產量維持。本研究將分析qDTY1.1、qDTY2.1、qDTY3.1、qDTY3.2、qDTY12.1對台灣栽培稻台南11號 (TN11) 以及台稉14號 (TK14) 水分利用效率之影響。TN11之導入系TN11-qDTY1.1/2.1/3.1與TN11-qDTY3.2和TN11-qDTY12.1相較於TN11有較低的蒸散量， TN11-qDTY1.1/2.1/3.1與TN11-qDTY3.2有更多的細根體積分佈表現，另qDTY12.1在導入TN11及TK14結果顯示在乾旱下有較好的氣孔導度維持，本研究也利用轉錄體定序 (RNA-seq) 進行全基因體表現分析，發現qDTY12.1區段的基因以及水通道蛋白相關基因，在TN11-qDTY12.1中的表現量相對親本TN11高，而TK14- qDTY12.1則相對親本TK14低。本研究結果顯示qDTYs的導入會影響植株的性狀表現以及提高水分利用效率，此外，在不同的親本中生理性狀和基因表現量也有差異性，表示qDTY的導入對植物生長的影響程度會受親本的不同而有差異。

Global climate change has led to frequent drought events, posing a serious threat to the growth and yield of many important food crops. How to improve the water use efficiency of rice and maintain sufficient rice yields is an important issue. Previous research on quantitative trait loci (qDTYs) related to drought tolerance has shown that rice can maintain a certain level of yield even under drought conditions. This study analyzes the impact of qDTY1.1, qDTY2.1, qDTY3.1, qDTY3.2, and qDTY12.1 on the water use efficiency of two Taiwanese cultivated rice varieties, Tainan 11 (TN11) and Taiken 14 (TK14). The introgression lines TN11-qDTY1.1/2.1/3.1, TN11-qDTY3.2, and TN11-qDTY12.1 showed lower transpiration rates compared to TN11. TN11-qDTY1.1/2.1/3.1 and TN11-qDTY3.2 exhibited greater distribution of fine root volume. Additionally, qDTY12.1, when introgressed into TN11 and TK14, demonstrated better stomatal conductance maintenance under drought conditions. The transcriptome sequencing (RNA-seq) analysis showed genes within the qDTY12.1 region and genes related to aquaporins exhibited higher expression levels in TN11-qDTY12.1 compared to TN11, whereas in TK14-qDTY12.1, these gene expression levels were relatively lower compared to TK14.The results of this study indicate that the introduction of qDTYs affects plant trait performance and enhances water use efficiency. Furthermore, there are variations in physiological traits and gene expression levels among different parents, suggesting that the impact of qDTY introgression on plant growth varies also depending on the genetic background.