分析不同水稻族群控制榖粒形狀之數量性狀基因座

QTL Analysis of Grain Shape in Different Rice Populations

林佳蓉(Jia-Rong Lin)

指導教授 ： 董致韡

國立臺灣大學/生物資源暨農學院/農藝學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202103516

摘要

大部分的農藝性狀包含水稻穀粒形狀是由多個數量性狀基因座 (quantitative trait loci, QTL) 所控制。本研究以秈稻IR64、稉稻Nipponbare雜交所產生的128個重組自交系 (recombinant inbred lines, RILs) 與來自82個國家的413個種原及89個國家的3,010種原，分析其種子長度、寬度等性狀，並配合高密度單一核苷酸多型性 (single nucleotide polymorphism, SNP)分子標誌進行全基因體關聯性研究 (genome-wide association study, GWAS)。首先將RILs偵測到榖粒形狀之顯著位點與前人發現的QTL進行比較；接著討論3組材料GWAS結果。在種子長度部分，RILs和自然族群偵測到不同的QTL；種子寬度部分，所有族群都偵測到主效QTL-GW5。最後比較413種原與3,010種原的次族群GWAS結果，在種子長度部分，可以發現因為次族群對偶基因頻度不同之故，導致偵測到最顯著的SNP不同，且即使都屬同一次族群，也可能因為起源地不同，偵測結果也有差異；另外種子寬度部分，各個次族群偵測到最顯著的SNP皆相同，皆為種子寬度的主效QTL-GW5，而該QTL目前也已運用在分子標誌輔助選種，透過偵測性狀相關的QTL，將優良的基因型導入不同品種，並且因應市場需求設計合理的穀粒大小，並在穀物產量和穀粒品質之間取得平衡。

關鍵字

穀粒形狀 ； 全基因體關聯性研究 ； 分子標誌輔助選種 ； 數量性狀基因座 ； 水稻(栽培種水稻) ； 種子長度 ； 單一核苷酸多型性 ； 種子寬度

並列摘要

Most agronomic traits, including rice grain shape, are controlled by multiple quantitative trait loci (QTL). In this study, 128 recombinant inbred lines (RILs) derived from a cross between IR64 and Nipponbare, 413 diverse accessions of Oryza sativa L. collected from 82 countries, and 3,010 rice accessions from 89 countries were used to analyze seed length, width and other grain traits by genome-wide association study (GWAS). First, the significant regions controlling grain shape in RILs were compared with the QTL identified before; then the results of GWAS for three sets of materials were presented and discussed. For seed length, different QTL were detected in RILs and natural populations; for seed width, the major QTL “GW5” was detected in all populations. Finally, the results of GWAS from 413 accessions and 3,010 accessions were compared. For seed length, different QTL were detected in these two diverse populations which could result from the different allele frequencies across different populations; if comparing the results between same subpopulations, the results could be differed due to accessions origins. For seed width, the major QTL “GW5” was detected in all subpopulations, GW5 has been used extensively in marker-assisted selection for seed size improvement. Once QTL are detected, the breeders could select and pyramid the elite alleles in rice cultivars, the various grain sizes could be designed to meet the needs for different market classes, and reach the balance between grain yield and grain quality.

並列關鍵字

grain shape ； genome-wide association study (GWAS) ； marker-assisted selection (MAS) ； quantitative trait loci (QTL) ； rice (cultivated rice, Oryza sativa L.) ； seed length ； single nucleotide polymorphism (SNP) ； seed width

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