高溫下稉稻多親本互交進階世代族群穀粒外觀品質之全基因體關聯性分析

Genome-wide Association Study on Grain Appearance Quality under High Temperature using Rice (Oryza sativa L. ssp. japonica) Multi-Parent Advanced Generation Inter-Cross Population

鄭同杉(Tung-Shan Cheng)

指導教授 ： 盧虎生

共同指導教授 ： 董致韡 ； 張孟基(Men-Chi Chang)

國立臺灣大學/生物資源暨農學院/農藝學研究所/碩士(2018年)

https://doi.org/10.6342/NTU201803552

摘要

全球暖化日漸加劇，高溫對於水稻品質的影響更為劇烈。為提供台灣地區水稻耐熱育種之參考依據，以利緩解高溫對於穀粒外觀品質的負面衝擊。本研究使用自國際水稻研究中心引進之稉稻多親本互交進階世代 (multi-parent advanced generation inter- cross, MAGIC)- japonica MAGIC作為材料，結合22190個單核苷酸多型性 (single nucleotide polymorphism, SNP)分子標誌，透過全基因體關聯性分析 (genome-wide association study, GWAS)和自行建立之影像分析系統，探討常溫與高溫下，穀粒長度、寬度以及白堊質程度的遺傳基礎。由性狀調查的結果得知，高溫處理加劇穀粒白堊質程度，並使粒型縮小，但不影響長寬比; 其中，穀粒寬度與白堊質程度在高溫之下呈現顯著正相關。由GWAS的分析，發現29個染色體區域在常溫之下與穀粒外觀品質相關; 25個染色體區域在高溫之下與穀粒外觀品質相關。不論常溫或高溫的GWAS結果中，皆有部分的染色體區域座落於已知的數量性狀基因座 (quantitative trait locus, QTL)。進一步檢驗堆疊QTL對於高溫之下白堊質程度的影響，發現堆疊較多優良QTL之MAGIC子代白堊質程度較低。最終，本篇研究提供japonica MAGIC族群內，與穀粒外觀品質相關之遺傳背景參考資訊，證明堆疊優良等位基因型用於水稻高溫白堊質育種之可行性，並建議選拔窄粒型之水稻以減少高溫下白堊質的增加。

關鍵字

水稻 ； 穀粒外觀品質 ； 高溫 ； 多親本互交進階世代族群 ； 全基因體關聯性分析

並列摘要

High temperature caused by climate change has dramatically reduced rice grain appearance quality in Taiwan. In order to improve grain appearance quality including grain length, width and chalkiness under high temperature, we conducted a genome-wide association study (GWAS) to identify grain appearance quality related genomic regions under ambient and high temperature using 409 accessions of Japonica multi-parent advanced generation inter-cross population (MAGIC) as diversity panel. Phenotypic analysis results suggested high temperature significantly increase grain chalkiness while reducing grain size without affecting length/width ratio. In addition, significant positive correlation between grain width and chalkiness value was observed under high temperature. GWAS using 22190 single nucleotide polymorphism (SNP) markers identified several genomic regions and some of them were co-localized in reported quantitative trait locus (QTL) or genes related to grain appearance quality. Based on the GWAS result of chalkiness under high temperature, favorable alleles were defined, accessions of japonica MAGIC carrying more favorable alleles had a significant reduction of chalkiness value suggesting the improvement of grain chalkiness could be achieved by QTLs pyramiding.

並列關鍵字

Rice appearance quality ； high temperature ； multi-parent advanced generation inter-cross ； GWAS

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