本文關(guān)鍵詞：玉米自交系齊319抗灰斑病主效位點(diǎn)qGLS1.02的精細(xì)定位　出處：《沈陽(yáng)農(nóng)業(yè)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 玉米 灰斑病 染色體片段置換系 精細(xì)定位 生物信息學(xué)

【摘要】：玉米灰斑病(Gray Leaf Spot,GLS)是一種在全世界廣泛分布的玉米真菌性病害,主要由玉蜀黍尾孢(Cercospora zeae-maydis和玉米尾孢(Cercospora zeina)引起,給玉米生產(chǎn)造成了極大危害。鑒定并利用抗病種質(zhì)資源改良我國(guó)骨干自交系以培育抗病品種是防治灰斑病發(fā)生的有效途徑。本課題組前期利用以抗病自交系齊319和感病自交系掖478構(gòu)建的包含300個(gè)家系的重組自交系(RIL)群體,結(jié)合由199個(gè)SSR標(biāo)記構(gòu)建的遺傳圖譜,根據(jù)2年灰斑病人工接種鑒定,在第1染色體binl.02位置發(fā)掘出了一個(gè)玉米抗灰斑病(玉蜀黍尾孢)主效QTL,qGLS1.02,兩端標(biāo)記為umc2614和bnlgl803,物理距離長(zhǎng)5.73Mb。本試驗(yàn)于2015年以齊319為供體親本、掖478為輪回親本構(gòu)建的19個(gè)BC5F3世代共9種不同基因型的染色體片段置換系為試驗(yàn)材料,采用人工接種對(duì)其衍生的19個(gè)BC5F4世代群體進(jìn)行灰斑病抗性鑒定,通過(guò)T檢驗(yàn)驗(yàn)證qGLS1.02初定位區(qū)間的抗病性,結(jié)果顯示來(lái)源于齊319的qGLSl.02片段能顯著提高掖478對(duì)灰斑病的抗性。從2015年的15SY15群體中篩選出的含有qGLS1.02全長(zhǎng)雜合片段的BC5F4單株進(jìn)行自交,將BC5F5世代單株用于重組體篩選,利用加密的分子標(biāo)記共篩選出了 10種重組體,進(jìn)一步于2016年將重組體回交衍生的10個(gè)BC5F6世代群體進(jìn)行抗病鑒定,通過(guò)群體抗病性分類、卡方檢驗(yàn)及T檢驗(yàn)等策略將qGLS1.02區(qū)間縮小到了 363.61Kb范圍內(nèi)。參照B73測(cè)序結(jié)果V2版本,根據(jù)網(wǎng)站Maize GDB分析結(jié)果,在精細(xì)定位區(qū)間內(nèi)存在5個(gè)基因,進(jìn)一步對(duì)該5個(gè)基因進(jìn)行生物信息學(xué)分析,進(jìn)行候選基因的預(yù)測(cè)。5個(gè)基因中只有KHB5在葉部表達(dá)量較高,同時(shí)具有明確、一致的功能預(yù)測(cè),將其作為預(yù)測(cè)的候選基因。利用候選基因KHB5臨近標(biāo)記SYLY_80對(duì)201份玉米自交系進(jìn)行基因分型,結(jié)合灰斑病抗性的鑒定結(jié)果,通過(guò)T檢驗(yàn)以驗(yàn)證該標(biāo)記對(duì)玉米灰斑病抗性選擇的有效性,結(jié)果顯示與齊319基因型相同的自交系整體抗病性顯著優(yōu)于其它自交系,說(shuō)明該標(biāo)記能夠?qū)τ衩谆野卟】剐赃M(jìn)行有效選擇。通過(guò)對(duì)qGLS1.02主效基因的精細(xì)定位、生物信息學(xué)預(yù)測(cè)及分子標(biāo)記的有效性驗(yàn)證為揭示玉米抗灰斑病菌的機(jī)理、分子標(biāo)記輔助育種的應(yīng)用提供了理論基礎(chǔ)。
[Abstract]:Gray Leaf spot (GLS) is a widely distributed fungal disease in maize all over the world. It is mainly caused by Cercospora zeae-maydis and Cercospora zeina. It is an effective way to control gray spot disease by identifying and using resistant germplasm resources to improve Chinese backbone inbred lines to cultivate disease-resistant varieties. A recombination inbred line consisting of 300 families was constructed from Ye478, a susceptible inbred line. The Ril group. Based on the genetic map constructed by 199 SSR markers, two years' work inoculation of gray spot patients was carried out. A dominant QTL QGLS1.02 was identified at the binl.02 site on chromosome 1 in maize resistant to gray spot disease (Cercospora zebra). The two ends were labeled as umc2614 and bnlgl803, and the physical distance was 5.73 Mb. in this experiment, Qi319 was used as donor parent in 2015. The chromosome fragment replacement lines of 9 different genotypes in 19 BC5F3 generations constructed by Ye 478 as recurrent parents were used as experimental materials. The resistance to gray spot disease was identified by artificial inoculation in 19 BC5F4 populations derived from it, and the disease resistance of qGLS1.02 initial locational interval was verified by T test. The results showed that the qGLSl.02 fragment derived from Qi319 could significantly increase the resistance of Y478 to gray spot disease. A total of qGLS1.02 was selected from 15SY15 population in 2015. The single BC5F4 plant with long heterozygous fragment was self-pollinated. BC5F5 generation single strain was used to screen the recombinant, and 10 kinds of recombinant were screened by using the encrypted molecular marker. In 2016, 10 BC5F6 generation populations derived from the recombinant were identified and classified by population disease resistance. Chi-square test and T test reduced the qGLS1.02 range to 363.61Kb, referring to the V2 version of B73 sequencing results. According to the results of Maize GDB analysis on the website, there were 5 genes in the fine mapping region, and the five genes were further analyzed by bioinformatics. Among the 5 genes, only KHB5 expression was higher in the leaves, and had a clear and consistent function prediction. The candidate gene was used as the candidate gene for prediction. 201 maize inbred lines were genotyped by using the candidate gene KHB5 adjacent marker SYLY_80, and the results of identification of resistance to gray spot disease were combined. T-test was used to verify the effectiveness of the marker in the selection of resistance to gray spot disease in maize. The results showed that the overall resistance of inbred lines with the same genotype as Qi319 was significantly better than that of other inbred lines. The results showed that the marker could be used to select the resistance to gray spot of maize effectively. The fine mapping of the main gene of qGLS1.02 was carried out. Bioinformatics prediction and validity verification of molecular markers provide a theoretical basis for revealing the mechanism of resistance to gray spot fungi in maize and the application of molecular marker assisted breeding.
【學(xué)位授予單位】：沈陽(yáng)農(nóng)業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：S435.131.4
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本文編號(hào)：1396963