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1.
Genetic resistance to common bunt is a cost-effective, environmentally friendly, and sustainable approach to controlling the disease. To date, 16 race specific common bunt resistance genes (Bt1-Bt15 and Btp) have been reported in wheat. However, a limited number have been mapped and few markers have been identified, which limits the usage of molecular markers in a marker-assisted breeding program. A total of 125 synthetic hexaploid wheats (SHWs) were evaluated for reactions to a mixture of common bunt races under field conditions in Turkey in 2016 and 2017. The objectives of this study were to identify common bunt resistant genotypes, identify genomic regions conferring resistance to common bunt using 35,798 genotyping-by-sequencing derived single nucleotide polymorphisms (SNPs), and investigate the significant SNPs present within genes using the functional annotations of the underlying genes. We found 29 resistant SHWs that can be used in wheat breeding. The genome-wide association study identified 15 SNPs associated with common bunt resistance and a haplotype block comprising three SNPs in perfect linkage disequilibrium. Five of them were novel and were located on chromosomes 2A, 3D, and 4A. Furthermore, seven of the 15 SNPs were found within genes and had annotations suggesting potential role in disease resistance. This study identified several favorable alleles that decreased common bunt incidence up to 26% in SHWs. These resistant SHWs and candidate genomic regions controlling common bunt resistance will be useful for wheat genetic improvement and could assist in further understanding of the genetic architecture of common bunt resistance.  相似文献   

2.
倒伏是影响玉米高产和机械化收获的重要因素,明确玉米抗倒伏相关性状的遗传基础,增强玉米品种抗倒伏能力,可为玉米高产宜机收育种提供理论依据。本研究以国内外收集的153份自交系为材料,利用6H90K SNP芯片检测的70,438个高质量SNP标记对地上第3节茎秆强度、株高、穗位高和穗位系数进行全基因组关联分析,分别检测到与茎秆强度、株高、穗位高和穗位系数相关位点5个、14个、16个和21个,单个关联位点最大效应值为13.24。同时以KA105/KB020的F5群体为试验材料,采用QTL IciMapping V4.2软件的完备区间作图法进行QTL定位,检测到21个与抗倒伏相关的QTL,可解释表型变异3.86%～16.58%。结合关联分析和连锁分析结果发现, 2个QTL区间与关联分析的候选区间重合。经过候选区段的基因功能注释和文献查阅,挖掘到GRMZM2G105391、GRMZM2G014119和GRMZM2G341410等与细胞壁生物合成、细胞分裂和细胞伸长的相关基因可供进一步分析。本研究结果为进一步解析玉米抗倒伏性状的遗传基础提供参考。  相似文献   

3.
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4.
Cowpea is an important legume crop widely grown in sub‐Saharan Africa for food and feed. However, it is largely challenged by bruchid, a serious storage pest resulting in losses in quantity and quality of grains. Therefore, this research was designed to contribute to the breeding of cowpea resistance to bruchid through the identification of candidate genes associated with resistance to bruchid. A total of 217 mini‐core cowpea accessions were genotyped and phenotyped for their reactions to bruchid. To determine the genomic regions linked with bruchid resistance, 41,948 polymorphic SNP markers were used. Genome‐wide association study identified 11 SNPs linked to the average number of eggs, holes, insect emergence and development period and Dobie susceptibility index. Gene search via Phytozome identified six candidate genes (Vigun08g132300, Vigun08g158000, Vigun06g053700, Vigun02g131000, Vigun01g234900 and Vigun01g201900) associated with the resistance traits. These candidate genes could be incorporated into the farmers preferred but susceptible cowpea varieties to bruchid. The SNP markers associated with the resistance traits can be used in marker‐assisted breeding for accurate and rapid screening of cowpea resistant genotypes to bruchid.  相似文献   

5.
玉米穗腐病是一种严重危害玉米生产的真菌性病害,而目前在世界范围内玉米育种上应用的大多数自交系缺少对穗腐病的抗性。玉米穗腐病抗性位点的挖掘和抗病基因的克隆,对玉米穗腐病的遗传改良至关重要。本研究旨在通过转录组测序和全基因组关联分析的方法进行玉米拟轮枝镰孢菌穗腐病抗性位点的挖掘并初步确定候选基因。抗病自交系法A和感病自交系掖81162的转录组测序结果表明,人工接种拟轮枝镰孢菌后7d两个自交系的差异表达基因有10,761个。通过全基因组关联分析共检测到5个与穗腐病抗性显著相关的SNP,这些SNP分布在1号和9号染色体上。通过比对B73 RefGen_v3并注释,发现SNP位点附近涉及的基因包括酰基激活酶1过氧化物酶体、蛋白磷酸酶2C 48、镁转运蛋白、受体蛋白激酶CRINKLY4和锌指CCCH域蛋白19。将在转录组测序中获得差异表达基因和全基因组选择中关联到的基因进行比对,发现全基因组关联分析中关联到的锌指CCCH域蛋白19同时也是转录组测序中获得的差异表达基因,表明锌指CCCH域蛋白19可能与玉米拟轮枝镰孢菌穗腐病的抗性相关。本研究结果不仅能为抗病基因的克隆和玉米的抗病分子育种提供一定的理论依据和重要的遗传资源,而且能为玉米和病原菌的相互作用机理的解析奠定基础。  相似文献   

6.
Downy mildew (DM) is a plant disease that strongly limits maize production. The resistance (R) genes for this disease have been identified and characterized and serve as important tools for plant disease evaluation. In this study, partial genes for PIC15, PO145579, and zmcf5 were identified and analyzed in a panel of 60 public and private maize inbred lines using bioinformatics and statistics tools. These candidate R genes exhibited an average nucleotide diversity value of 0.015. The negative Tajima’s D values for these genes suggested that purifying selection has played a role in the evolution of maize DM resistance genes. In addition, linkage disequilibrium among these genes occurred across an extent of ~ 200 bp. Using association analysis methods, a general linear model, and a mixed linear model, five polymorphisms within the partial PIC15 and PO145579 genes were detected and associated with DM disease. These are new polymorphisms that have not previously been reported in association with DM disease traits. Therefore, correlations between these new polymorphisms and DM disease in these germplasm collections could advance the development of a functional marker for marker-assisted selection of DM disease resistance in maize breeding programs.  相似文献   

7.
Saturated fatty acids (FA), an important component of soybean oil, plays a crucial role in the nutritional value of soybean oil through different concentration and relative proportions. In this study, an association population of 185 diverse soybean accessions was used to identify quantitative trait nucleotide (QTN) and scan candidate genes via genome‐wide association analysis (GWAS), which was based on high throughout single‐nucleotide polymorphisms (SNPs) developed via the Specific Locus Amplified Fragment Sequencing (SLAF‐seq) approach. A total of 33,149 SNPs were identified with minor allele frequencies (MAF) >4%, which covered 97% of the soybean whole genome. For the two saturated FA concentration, including palmitic acid (PA) and stearic acid (SA), up to 65 SNPs were verified via GWAS. Among them, 35 and 16 SNPs loci were the novel loci for PA and SA, respectively. There were other six loci for PA and eight loci for SA overlapped or located in the linked genomic regions reported by the previous study. Furthermore, many loci were repeated in more than two environments, and four pair of pleiotropic loci (PA‐3‐2 and SA‐3‐2, PA‐11‐2 and SA‐11‐1, PA‐12‐2 and SA‐12‐1, and PA‐17‐1 and SA‐17‐2) had similar genomic regions, which might control both PA and SA simultaneously. A total of 49 genes, which could participate in lipid biosynthesis pathway or hormone metabolism, were identified as the potential candidate genes associated with saturated FA. The identified loci with beneficial alleles and the candidate genes would be valuable for studying the molecular mechanisms of saturated FA and further for improving nutritional value of soybean oil.  相似文献   

8.
玉米穗行数全基因组关联分析   总被引：6，自引：1，他引：5  
穗行数是玉米产量的重要组成性状,其遗传解析对高产育种具有指导意义。本文以203份主要玉米自交系为材料,2007年在新疆乌鲁木齐、吉林公主岭和海南三亚进行穗行数测定;采用分布于玉米基因组的41 101个单核苷酸多态性(SNP)标记对穗行数进行关联分析。共鉴定出9个与穗行数显著关联(P0.0001)的SNP,分别位于染色体框1.02、1.10、7.03、8.02、9.06和10.03。8个SNP位于已定位的数量性状座位(QTL)区间内。在显著SNP位点LD区域内发掘出4个候选基因,分别编码含F-box结构域的生长素受体蛋白、玉米kn1蛋白、AP2结构域蛋白和富亮氨酸重复的跨膜蛋白激酶。采用全基因组关联分析策略发掘穗行数基因位点及候选基因,将为克隆控制玉米产量性状基因奠定基础。  相似文献   

9.
白叶枯病是水稻生产最严重的细菌性病害,挖掘新的白叶枯病抗性基因资源并培育抗病品种是控制该病害的重要方法。本研究利用父母本抗性差异较大的协优9308衍生的139个重组自交系群体作为遗传材料,人工接种不同白叶枯菌后的病斑长度作为连续型表型,结合经DNA深度测序获得的476,505个单核苷酸多态性(single-nucleotide polymorphism,SNP)标记进行全基因组关联分析(genome-wide associated study,GWAS)。结果表明在P<1×10–4下, 4个菌株处理后共鉴定到109个与白叶枯抗性显著关联的SNPs位点,解释表型变异率59.78%～63.29%。其中CR4接种发现了25个SNP位点其贡献率为61.00%,在这些SNP位点附近共筛选到19个基因,其中有2个为NBS-LRR抗病相关基因(LOCOs11g43420和LOCOs11g45930)。表达分析验证发现该2个基因在抗性亲本中恢9308的表达量分别为感病母本协青早B的4.42倍和8.86倍,表明其可能在正调控白叶枯病...  相似文献   

10.
To develop genetic markers associated with tolerance to low phosphorus, we identified candidate phosphate starvation responsive (PSR) genes and developed their intron length polymorphism (ILP) markers in maize on a genome‐wide scale. Based on the known plant PSR genes, 161 candidate PSR genes were identified. Of these genes, 138 genes contained at least one intron and were then used to develop 606 PSR‐ILP markers by designing PCR primers to the intron‐flanking exonic regions. PCR evaluation was performed on 43 randomly selected PSR‐ILP markers in 30 maize inbred lines. Of the primers, 88.4% amplified stable and pure products in all maize inbred lines, and 53.5% of the markers showed ILP, with PIC values ranging from 0.06 to 0.80. The result of clustering analysis of the 30 maize inbred lines, based on the polymorphism of 23 ILP markers, suggests that the ILP markers developed in this study are not only efficient for genetic diversity analysis but also potentially useful for marker assisted selection for tolerance to low phosphorus.  相似文献   

11.
Morphological traits for ear leaf are determinant traits influencing plant architecture and drought tolerance in maize. However, the genetic controls of ear leaf architecture traits remain poorly understood under drought stress. Here, we identified 100 quantitative trait loci (QTLs) for leaf angle, leaf orientation value, leaf length, leaf width, leaf size and leaf shape value of ear leaf across four populations under drought‐stressed and unstressed conditions, which explained 0.71%–20.62% of phenotypic variation in single watering condition. Forty‐five of the 100 QTLs were identified under water‐stressed conditions, and 29 stable QTLs (sQTLs) were identified under water‐stressed conditions, which could be useful for the genetic improvement of maize drought tolerance via QTL pyramiding. We further integrated 27 independent QTL studies in a meta‐analysis to identify 21 meta‐QTLs (mQTLs). Then, 24 candidate genes controlling leaf architecture traits coincided with 20 corresponding mQTLs. Thus, new/valuable information on quantitative traits has shed some light on the molecular mechanisms responsible for leaf architecture traits affected by watering conditions. Furthermore, alleles for leaf architecture traits provide useful targets for marker‐assisted selection to generate high‐yielding maize varieties.  相似文献   

12.
Field grain drying rate (FDR) after physiological maturity in maize (Zea mays L.) is an essential determinant of grain moisture at harvest. Investigating the genetic structure of FDR is of great significance to breeding maize hybrids with low grain moisture at harvest that are suitable for mechanical harvesting. In this study, 80 elite maize inbred lines from Jilin Province (China) were selected as an association population, and their FDR after physiological maturity was determined by the oven-drying method in 2014 and 2015. At the same time, whole-genome resequencing was performed for the association population, and 1,490,007 high-quality single nucleotide polymorphisms (SNPs) were obtained for a subsequent genome-wide association study. The results showed high genetic variation for FDR in different maize inbred lines, with a broad-sense heritability of 0.76, indicating that the trait is mainly controlled by genetic factors. Thirteen independent genomic positions, which contain 19 SNP markers significantly associated with FDR in maize (P < 0.000001), were detected by a genome-wide association study in 2014 and 2015. Seven genomic positions were located within the quantitative trait loci previously mapped for FDR, whereas one position was detected in both years by association analysis. Six candidate genes located in chromosome bins 4.05, 5.04 and 7.02 were identified within the 13 genomic positions. These genes were predicted to encode vegetative cell wall gp1-like glycoprotein, phosphopyruvate hydratase, mitochondrial inner membrane protease subunit 1-like protein, Cucumber mosaic virus 1a interacting protein 1 and two hypothetical proteins, which may be closely associated with FDR. The results lay a foundation for molecular marker-assisted selection of maize materials with rapid grain drying and for the cloning of relevant functional genes.  相似文献   

13.
玉米种子萌发相关性状的全基因组关联分析   总被引：1，自引：0，他引：1  
种子萌发是出苗的前提, 对玉米产量影响重大。为了解玉米种子萌发相关性状的遗传机制, 本研究对476份玉米自交系种子萌发相关的6个性状进行调查, 结合125万个(1.25M) SNP标记, 利用3种统计模型(Q, K, Q+K)进行全基因关联分析(GWAS)。结果表明K模型能够较好地评价吸胀前重量、吸胀前体积、吸胀后重量、吸胀后体积和吸胀体积5个性状; Q+K模型能更好地评价吸胀重量性状。基于这6个性状的最优模型的GWAS结果, 共检测到15个种子萌发相关性状的显著SNP, 15个SNP对应6个QTL, 集中分布在玉米第3、第6、第7和第10染色体上, QTL内单个SNP能解释的表型变异为5.09%~7.85%。其中5个QTL可在多个生物学重复中被检测到。以最显著SNP所在基因或附近基因作为QTL的候选基因, 共筛选到6个最可能的候选基因。GRMZM2G148411是吸胀后重量、吸胀重量和吸胀体积3个性状共同鉴定到的QTL候选基因, 根据基因的功能注释, 该基因编码一个包含TLD-domain的钙离子结合蛋白, 可能是一种调控种子休眠与萌发的信号分子。本研究鉴定的QTL为解析玉米种子萌发的遗传机制和相应功能标记的开发奠定了基础。  相似文献   

14.
Root‐knot nematode disease, caused by Meloidogyne species, is an important soil‐borne disease of peach (Prunus persica L.) worldwide. To identify a major locus of genetic resistance to M. incognita, PkMi, in a wild peach species, we reconstructed a linkage group in a BC1 population of 187 lines using resistance gene analogue markers surrounding the PkMi locus. A resistance gene analogue marker, ppa021062m, co‐segregated with the PkMi locus and was therefore considered a strong candidate for PkMi. Phylogenetic analysis of the deduced protein sequences of ppa021062m, together with the other seven genes for nematode resistance, allowed ppa021062m to be assigned to the Toll/Interleukin1 Receptor‐Nucleotide Binding Site‐Leucine Rich Repeat class, similar to Ma in myrobalan plum (P. cerasifera). Comparative analysis of the candidate gene sequence in four genotypes that had different levels of resistance to root‐knot nematode disease showed that most non‐synonymous SNPs in the genic region were distributed in the TIR and NBS motifs. This study enhances our understanding of the genetic and molecular control of resistance to root‐knot nematode disease in peach.  相似文献   

15.
Plant architecture and yield components are critical for the determination of seed yield in soybean. In this study, we performed genetic association analysis to dissect the relationships between plant architecture and yield component traits. Two hundred and nineteen accessions were employed, and eight agronomic traits were evaluated in six environments. Our results revealed strong positive correlations of plant architecture traits with yield components and the significant association of 4 SNPs with plant architecture traits and of 7 SNPs with yield component traits in two or more environments. Eight SNPs were co‐associated with two traits. Based on the phenotypic effects of the alleles of the detected SNPs, the best alleles were mined for twenty‐three distinct SNPs. Fifteen typical carrier materials harbouring the best allele effects were also mined. Twenty parental combinations were proposed by pyramiding possible alleles per SNP in one individual (excluding possible epistatic effects). These proposed combinations with the best alleles and carrier materials will aid in the improvement of targeted traits and marker‐assisted selection (MAS) efficiency in soybean breeding.  相似文献   

16.
Phytophthora root rot (PRR) is among the most important soybean (Glycine max (L.) Merr.) diseases worldwide, and the host displays complex genetic resistance. A genome-wide association study was performed on 337 accessions from the Yangtze-Huai soybean breeding germplasm to identify resistance regions associated with PRR resistance using 60,862 high-quality single nucleotide polymorphisms markers. Twenty-six significant SNP-trait associations were detected on chromosomes 01 using a mixed linear model with the Q matrix and K matrix as covariates. In addition, twenty-six SNPs belonged to three adjacent haplotype blocks according to a linkage disequilibrium blocks analysis, and no previous studies have reported resistance loci in this 441 kb region. The real-time RT-PCR analysis of the possible candidate genes showed that two genes (Glyma01g32800 and Glyma01g32855) are likely involved in PRR resistance. Markers associated with resistance can contribute to marker-assisted selection in breeding programs. Analyses of candidate genes can lay a foundation for exploring the mechanism of P. sojae resistance.  相似文献   

17.
广谱抗性基因的挖掘是马铃薯高抗晚疫病品种选育的基础。本研究以288份国际马铃薯中心筛选的晚疫病抗性群体为试验材料,经过连续2年田间调查,计算AUDPC和sAUDPC值,评估群体晚疫病抗性;利用SLAF-seq方法进行群体简化基因组测序,通过对晚疫病抗性表型数据的全基因组关联分析,挖掘晚疫病抗性相关的遗传位点和候选基因,为晚疫病抗性品种选育和抗病机理研究提供一定的理论和材料基础。结果表明,晚疫病抗性在288份材料间存在着广泛的遗传差异;基于5种分析模型,共鉴定到82个与晚疫病抗性显著关联的位点;在关联区间关联到54个已知或可能与晚疫病抗性相关的基因。其中,23个基因为抗性基因,包括晚疫病抗性基因R1同源基因、Sw-5同源基因(R8)和Rpi-vnt1以及编码多效性耐药蛋白基因;5个基因编码MAPK蛋白和WRKY转录因子;1个基因参与茉莉酸途径;3个基因与水杨酸途径相关;6个基因是病程相关的基因;3个基因参与苯基丙酸类合成途径;其他与晚疫病抗性相关的基因,如HMGR基因(2个)、细胞色素P450(21个)。  相似文献   

18.
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19.
Maize root system architecture determines key functions of uptake of water and nutrients in plants. A large number of quantitative trait loci (QTLs) of root-related traits have been found in different populations of maize. Identification of consistent QTLs across diverse genetic backgrounds could be instrumental on marker-assisted selection of traits and identification of candidate functional genes. In this study, 20 published papers were investigated regarding on reported results of QTLs related to root traits of maize, and in total 428 individual QTLs for 23 root-related traits were used for meta-analysis, resulting in 53 Meta-QTLs (MQTLs) retrieved over ten maize chromosomes. Among these MQTLs regions, in total 45 maize homologs were considered as candidate genes affecting maize root traits by comparing with 7 genes from rice and 36 genes from Arabidopsis. Three maize genes (GRMZM5G813206, GRMZM2G167220 and GRMZM2G467069) identified from MQTL8-5 could play important roles on lateral root and crown root development of maize. Two of the MQTLs, i.e. MQTL7-2 and MQTL9-1, involved in nitrogen (N) and phosphorus (P) stress responses and both of them with small physical distance (less than 3 Mb), could be used for abiotic stress improvement of maize root traits. These MQTLs and candidate genes will be helpful for future gene cloning and marker-assisted selection in maize.  相似文献   

20.
Turcicum or northern corn leaf blight (NCLB) incited by the ascomycete Setosphaeria turcica, anamorph Exserohilum turcicum, is a ubiquitous foliar disease of maize. Diverse sources of qualitative and quantitative resistance are available but qualitative resistances (Ht genes) are often unstable. In the tropics especially, they are either overcome by new virulent races or they suffer from climatically sensitive expression. Quantitative resistance is expressed independently of the physical environment and has never succumbed to S. turcica pathotypes in the field. This review emphasizes the identification and mapping of genes related to quantitative NCLB resistance. We deal with the consistency of the genomic positions of quantitative trait loci (QTL) controlling resistance across different maize populations, and with the clustering of genes for resistance to S. turcica and other fungal pathogens or insect pests in the maize genome. Implications from these findings for further genomic research and resistance breeding are drawn. Incubation period (IP) and area under the disease progress curve (AUDPC), based on multiple disease ratings, are important component traits of quantitative NCLB resistance. They are generally tightly correlated (rp? 0.8) and highly heritable (h2? 0.75). QTL for resistance to NCLB (IP and AUDPC) were identified and characterized in three mapping populations (A, B, C). Population A, a set of 121‐150 F3 families of the cross B52×mo17, represented US Corn Belt germplasm with a moderate level of resistance. It was field‐tested in Iowa, USA, and Kenya, and genotyped at 112 restriction fragment length polymorphism (RFLP) loci. Population B consisted of 194‐256 F3 families of the cross Lo951×CML202, the first parent being a Corn‐Belt‐derived European inbred line and the second parent being a highly resistant tropical African inbred line. The population was also tested in Kenya and genotyped with 110 RFLP markers. Population C was derived from a cross between two early‐maturing European inbred lines, D32 and D145, both having a moderate level of resistance. A total of 220 F3 families were tested in Switzerland and characterized with 87 RFLP and seven SSR markers. In each of the three studies, 12‐13 QTL were detected by composite interval mapping at a signifcance threshold of LOD=2.5. The phenotypic and the genotypic variance were explained to an extent of 50‐70% and 60‐80%, respectively. Gene action was additive to partly dominant, as in previous generation means and combining ability analyses with other genetic material. In each population, gene effects of the QTL were of similar magnitude and no putative major genes were discovered. QTL for AUDPC were located on chromosomes 1 to 9. All three populations carried QTL in identical genomic regions on chromosomes 3 (bin 3.06/07), 5 (bin 3.06/07) and 8 (bin 8.05/06). The major genes Ht2 and Htn1 were also mapped to bins 8.05 and 8.06, suggesting the presence of a cluster of closely linked major and minor genes. The chromosomal bins 3.05, 5.04 and 8.05, or adjacent intervals, were further associated with QTL and major genes for resistance to eight other fungal diseases and insect pests of maize. Bins 1.05/07 and 9.05 were found to carry population‐specifc genes for resistance to S. turcica and other organisms. Several disease lesion mimic mutations, resistance gene analogues and genes encoding pathogenesis‐related proteins were mapped to regions harbouring NCLB resistance QTL.  相似文献   

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