- resistance in maize. - Background: Fusarium ear rot (FER) caused by Fusarium verticillioides is a major disease of maize that reduces grain yield and quality globally. - Result: To gain a comprehensive understanding of the genetic basis of natural variation in FER resistance, a recombinant inbred lines (RIL) population and one panel of inbred lines were used to map quantitative trait loci (QTL) for resistance. - As a result, a total of 10 QTL were identified by linkage mapping under four environments, which were located on six chromosomes and explained of the phenotypic variation. - Epistatic mapping detected four pairs of QTL that showed significant epistasis effects, explaining of the phenotypic variation.. - Full list of author information is available at the end of the article. - Fusarium ear rot (FER) is one of the most important food and feed safety challenges in global maize produc- tion [1]. - FER not only reduces the yield and quality of harvested maize but also is fatal to humans and animals, which consume the contaminated grain containing my- cotoxins from some of the Fusarium spp. - Fusarium verticillioides is an important maize patho- gen in the world, which can lead to serious economic losses [6], particularly in China [7–9], the United States [10] and Southern Europe [11, 12]. - Resistance to FER is complex because it is character- ized by a quantitative inheritance in which additive, dominant, epistatic, and genotype by environment inter- action effects are important [18 – 21]. - Based on biparental populations, Mapping studies have shown that resistance to FER is controlled by many genes with relatively small effects that vary in environments and populations [4, 22]. - Although different maize inbred lines and hybrids own different genetic variation for resistance to FER, there is no evidence of maize materials with complete resistance to either FER or fumonisin contamination in maize [23–25]. - resistance to F. - [21] detected 13 QTL for kernel resistance to FER, which displayed significant QTL × environment interactions, and Chen et al. - discovered a QTL for FER resistance affecting approxi- mately 18% of the phenotypic variation and accounting for up to 35% of the phenotypic effect in near isogenic lines when in homozygosity. - [27] detected a resistance QTL with 10.2% of the phenotypic variation, but no epistatic effects were de- tected. - Cer- tainly, there are many other studies on resistance to FER based on linkage mapping. - Now many quantitative traits have been successfully studied by GWAS in maize [35]. - Then, GWAS was performed based on the data collected from five environments to detect al- leles associated with resistance to FER. - Last, we discussed the probable mechanism of resistance to FER and stable QTL for molecular breeding.. - First of all, we determined the best time of inoculation for ear rot. - For determining the proper inoculation time, we evaluated the phenotype of six inoculation periods of the resistant materials, BT-1 and CML295, and suscep- tible N6 from the 5th to the 35th day after silking (Fig.. - Descriptive statistics for FER resistance in the RIL and GWAS populations are presented in Table 1. - The frequency of phenotypic value of the GWAS population for resistance followed an approximately normal distribution, but a skewed distribution in the RIL (Fig. - The high heritability indicated that much of the phenotypic variance was gen- etically controlled in the populations and suitable for QTL mapping.. - Among these QTL, three QTL were lo- cated on chromosome 4 (bin 4.05/08) and the one WQ6 (bin 4.05/06) between markers mmc0371 and A007339 had the largest resistance effect for Fusarium ear rot, which could explain more than 9.3% of the phenotypic variation. - explained 25.1% of the phenotypic variation, whereas interaction effects explained only 5.5%.. - A total of three pairs of QTL inter- actions were detected by the ICIM-EPI method at an LOD value of 7, which explained 3.2, 2.4, and 2.4% of the phenotypic variation (Table S1, Fig. - Al- though each QTL had the negative additive effect, the interaction effect showed a positive effect, which re- volved the complexity of the resistance to FER.. - The most sig- nificant SNP was located on chromosome 7 (S with the lowest P value and it ex- plained 10.2% of the phenotypic variation. - The second SNP with the lowest P value was located on chromo- some 4 and explained 6.8% of the phenotypic variation.. - Based on the physical pos- ition of the significant SNPs in the B73 version 2 reference genome, these significant SNPs were associ- ated with 11 candidate genes, some of which were dir- ectly involved in resistance according to gene annotation, GRMZM2G150179, for example.. - Conjoint analysis for FER resistance. - The analysis of variance also showed the same result, which indicated that these three QTL could increase resistance to FER. - The de- tailed genotypes and phenotypes of the three NILs can been found in the supplementary materials (Table S2, Fig. - QTL analysis and GWAS for FER resistance. - in maize [48]. - However, GWAS easily gener- ates false positive results because of the population structure. - To decrease the loss from FER and explore the genetic mechanism, we begin to study resistance to FER more than a decade years ago. - verticillioides ear rot resistance in maize. - GRMZM2G059381 be- longs to the AMP-binding protein and the homologous OsBIABP1 is involved in the regulation of the defense re- sponse through salicylic acid (SA) and/or jasmonic acid (JA. - GRMZM2G463471 is a member of the actin-depolymerizing factors (ADFs), whose primarily function is to regulate the severing and depolymerization of actin filaments. - [55] found a member of ADFs, e.g., TaADF4, from wheat, was required for resistance to the stripe rust pathogen Puccinia striiformis f. - These results indicate that the three candidate genes in this study may be associated with FER resistance in maize, which will be focused on in the following study.. - Phenotypic evaluation for FER resistance. - The acquisition of the phenotype was influenced by the. - Among them, the last method is widely used because of easy control of the inoculation dose.. - This method is most suitable for inoculation in the milk rip- ening period, the 15th day after silking, because earlier or later inoculation can not accurately reflect the resist- ance of the materials. - Four QTL of the five common loci in the RIL and GWAS were verified in NILs and three candidate genes may be associated with FER resist- ance. - At the same time, it was feasible to select maize lines with higher Fu- sarium resistance because of the two stable QTL in dif- ferent tissues and studies.. - The line BT-1 was reformed by tropical Asia material with highest resistance to FER, which was screened out of 90 inbred lines inoculated with Fusar- ium verticillioides [63], whereas the susceptible N6 was a Tangsipingtou line. - b) Comparison of QTL and SNPs for Fusarium ear rot resistance detected by previous reports. - Resistance to FER was assessed by disease severity ac- cording to Reid et al. - In our previous study, we constructed a linkage map of the RIL population (BT × N6), which contained 207 polymorphic SSR markers and had a length of 1820.8 cM with an average 11.7 cM distance [27]. - FER: Fusarium ear rot. - This work was financially supported by the International (Regional) Joint Research Project of the National Natural Science Foundation of China (Grant No. - This study was supported by the International (Regional) Joint Research Project of the National Natural Science Foundation of China (Grant No.. - Fumonisins in maize: can we reduce their occurrence. - Relationship between kernel drydown rate and resistance to Gibberella ear rot in maize. - Breeding for resistance to ear rots caused by Fusarium spp. - in maize – a review. - Causing Maize Ear Rot and Potential Mycotoxin Production in China. - Identification of pathogen causing maize ear rot and inoculation technique in Southwest China. - Epidemiology of Fusarium diseases and their mycotoxins in maize ears. - Biodiversity of Fusarium species in Mexico associated with ear rot in maize, and their identification using a phylogenetic approach. - Gene action and reciprocal effects for ear rot resistance in crosses derived from five tropical maize populations.. - QTL mapping for Fusarium ear rot and Fumonisin contamination resistance in two maize populations. - Gent action affecting host resistance to Fusarium ear rot of maize. - Detection and verification of quantitative trait loci for resistance to Fusarium ear rot in maize. - QTL mapping of resistance to Fusarium ear rot using a ril population in maize. - QTL mapping of Fusarium moniliforme ear rot resistance in highland maize, Mexico.. - Molecular basis of resistance to Fusarium ear rot in maize. - Sources of resistance to fumonisin accumulation in grain and Fusarium ear and kernel rot of corn.. - Evaluation of inoculation techniques for Fusarium ear rot and fumonisin contamination of corn. - Evaluation of broad spectrum sources of resistance to Fusarium verticillioides and advanced maize breeding lines. - Molecular mapping of QTL for resistance to maize ear rot caused by Fusarium moniliforme. - A new QTL for resistance to Fusarium ear rot in maize. - Role of the European corn borer (Ostrinia nubilalis) on contamination of maize with 13 Fusarium mycotoxins. - Characterization of correlation between grain moisture and ear rot resistance in maize by QTL meta- analysis. - QTL mapping and candidate genes for resistance to Fusarium ear rot and fumonisin contamination in maize. - Genome-wide association studies in maize: praise and stargaze. - Genome-wide association study and QTL mapping reveal genomic loci associated with Fusarium ear rot resistance in tropical maize germplasm. - QTL for resistance to Fusarium ear rot in a multiparent advanced generation intercross (MAGIC) maize population. - Genome-wide association study of resistance to ear rot by, in a tropical field maize and popcorn core collection. - Genome- wide association study of Fusarium ear rot disease in the U.S.A. - A genome-wide association study reveals genes associated with Fusarium ear rot resistance in a maize core diversity panel. - Low validation rate of quantitative trait loci for gibberella ear rot resistance in European maize. - Field inoculation and classification of maize ear rot caused by Fusarium verticillioides. - Dissecting the genetic architecture of Fusarium verticillioides seed rot resistance in maize by combining QTL mapping and genome-wide association analysis. - The mechanisms of maize resistance to Fusarium verticillioides by comprehensive analysis of RNA-seq data. - Genetic analysis of cob resistance to F.. - verticillioides: another step towards the protection of maize from ear rot.. - TaADF4, an actin-depolymerizing factor from wheat, is required for resistance to the stripe rust pathogen Puccinia striiformis f. - A Genome Wide Association Study Reveals Markers and Genes Associated with Resistance to Fusarium verticillioides Infection of Seedlings in a Maize Diversity Panel. - Quantitative trait loci mapping for Gibberella ear rot resistance and associated agronomic traits using genotyping-by-sequencing in maize. - A meta-analysis of QTL associated with ear rot resistance in maize. - Identification of resistance on maize germplasm to maize ear rot. - Evidence for a gene for silk resistance to Fusarium graminearum Schw. - Ear rot of maize. - Combined linkage and association mapping reveals qtl and candidate genes for plant and ear height in maize
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