中國(guó)農(nóng)業(yè)大學(xué)教授李建生及其合作者,，首次在全基因組水平上對(duì)玉米籽粒油分的遺傳基礎(chǔ)進(jìn)行了深入解析,。相關(guān)成果日前在線發(fā)表于《自然—遺傳學(xué)》雜志。
玉米是我國(guó)第一大糧食作物,。油分是玉米籽粒最重要的營(yíng)養(yǎng)成分之一,，其能量密度和價(jià)值顯著高于淀粉,。普通玉米中油分含量一般為4%,，經(jīng)過(guò)人工不斷選育后的高油玉米材料油分含量可達(dá)到20%,。但目前在全基因水平上，高油玉米形成的遺傳基礎(chǔ)尚不明確,。
來(lái)自中國(guó)農(nóng)業(yè)大學(xué)與華中農(nóng)業(yè)大學(xué),、中國(guó)農(nóng)科院、深圳華大基因,、美國(guó)農(nóng)業(yè)部的研究人員,，利用包括高油玉米在內(nèi)的368份玉米自交系為材料，通過(guò)RNA測(cè)序獲得了100多萬(wàn)個(gè)單核苷酸多態(tài)性位點(diǎn),，并利用全基因組關(guān)聯(lián)分析方法,，對(duì)籽粒油分相關(guān)性狀進(jìn)行了分析，共發(fā)現(xiàn)74個(gè)基因與籽?？傆头旨敖M分顯著關(guān)聯(lián),，其中三分之一是編碼油脂代謝的關(guān)鍵酶基因，包括26個(gè)與玉米籽?？偤土匡@著相關(guān)的基因,，這些基因可解釋總油分83%的表型變異。
研究發(fā)現(xiàn),，人工長(zhǎng)期選擇的高油玉米僅在有限基因組位點(diǎn)發(fā)生改變,，有利等位基因的累加可能是高油玉米油分增加的主要原因。
相關(guān)專家表示,，該研究為剖析玉米籽粒油分形成的遺傳結(jié)構(gòu)提供了理論基礎(chǔ),，對(duì)進(jìn)一步改良玉米油分的含量和質(zhì)量有重要指導(dǎo)意義。不過(guò),，揭示關(guān)鍵基因的作用機(jī)制還有待于更細(xì)致的研究,，同時(shí)將這些研究成果最終應(yīng)用于高油玉米的培育，仍有很多工作要做,。(生物谷Bioon.com)
doi:10.1038/ng.2484
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Genome-wide association study dissects the genetic architecture of oil biosynthesis in maize kernels
Hui Li, Zhiyu Peng, Xiaohong Yang, Weidong Wang, Junjie Fu, Jianhua Wang, Yingjia Han,Yuchao Chai, Tingting Guo, Ning Yang, Jie Liu, Marilyn L Warburton, Yanbing Cheng,Xiaomin Hao, Pan Zhang, Jinyang Zhao, Yunjun Liu, Guoying Wang, Jiansheng Li & Jianbing Yan
Maize kernel oil is a valuable source of nutrition. Here we extensively examine the genetic architecture of maize oil biosynthesis in a genome-wide association study using 1.03 million SNPs characterized in 368 maize inbred lines, including 'high-oil' lines. We identified 74 loci significantly associated with kernel oil concentration and fatty acid composition (P < 1.8 × 10−6), which we subsequently examined using expression quantitative trait loci (QTL) mapping, linkage mapping and coexpression analysis. More than half of the identified loci localized in mapped QTL intervals, and one-third of the candidate genes were annotated as enzymes in the oil metabolic pathway. The 26 loci associated with oil concentration could explain up to 83% of the phenotypic variation using a simple additive model. Our results provide insights into the genetic basis of oil biosynthesis in maize kernels and may facilitate marker-based breeding for oil quantity and quality.
