scholarly journals Precise Mapping of Quantitative Trait Loci for Resistance to Southern Leaf Blight, Caused by Cochliobolus heterostrophus Race O, and Flowering Time Using Advanced Intercross Maize Lines

Genetics ◽  
2007 ◽  
Vol 176 (1) ◽  
pp. 645-657 ◽  
Author(s):  
P. J. Balint-Kurti ◽  
J. C. Zwonitzer ◽  
R. J. Wisser ◽  
M. L. Carson ◽  
M. A. Oropeza-Rosas ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Flowering Time ◽  
Quantitative Trait ◽  
Leaf Blight ◽  
Cochliobolus Heterostrophus ◽  
Precise Mapping ◽  
Trait Loci ◽  
Southern Leaf Blight

scholarly journals Identification and Mapping of Quantitative Trait Loci Conditioning Resistance to Southern Leaf Blight of Maize Caused by Cochliobolus heterostrophus Race O

2004 ◽  
Vol 94 (8) ◽  
pp. 862-867 ◽  
Author(s):  
M. L. Carson ◽  
C. W. Stuber ◽  
M. L. Senior
Keyword(s):  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Leaf Blight ◽  
Chromosome 1 ◽  
Cochliobolus Heterostrophus ◽  
Phenotypic Variance ◽  
Polygenic Inheritance ◽  
Trait Loci ◽  
Southern Leaf Blight ◽  
Ri Lines

A random set of recombinant inbred (RI) lines (F2:7) derived from the cross of the inbred lines Mo17 (resistant) and B73 (susceptible) were evaluated for resistance to southern leaf blight (SLB) caused by Cochliobolus heterostrophus race O. The RI lines were genotyped at a total of 234 simple sequence repeat, restriction fragment length polymorphism, or isozyme loci. Field plots of the RI lines were inoculated artificially with an aggressive isolate of C. heterostrophus race O in each of two growing seasons in North Carolina. Lines were rated for percent SLB severity two (1996) or three (1995) times during the grain-filling period. Data also were converted to area under the disease progress curve (AUDPC) and analyzed using the composite interval mapping option of the PLABQTL program. When means of disease ratings over years were fitted to models, a total of 11 quantitative trait loci (QTLs) were found to condition resistance to SLB, depending upon which disease ratings were used in the analyses. When the AUDPC data were combined and analyzed over environments, seven QTLs, on chromosomes 1, 2, 3, 4, 7, and 10 were found to come from the resistant parent Mo17. An additional QTL for resistance on chromosome 1 came from the susceptible parent B73. The eight identified QTLs accounted for 46% of the phenotypic variation for resistance. QTL × environment interactions often were highly significant but, with one exception, were the result of differences in the magnitude of QTL effects between years and not due to changes in direction of effects. QTLs on the long arm of chromosome 1 and chromosomes 2 and 3 had the largest effects, were the most consistently detected, and accounted for most of the phenotypic variance. No significant additive × additive epistatic effects were detected. These data support earlier reports of the polygenic inheritance of resistance to SLB of maize.

Mapping quantitative trait loci associated with southern leaf blight resistance in maize ( Zea mays L.)

2019 ◽  
Vol 167 (10) ◽  
pp. 591-600 ◽  
Author(s):  
Maninder Kaur ◽  
Yogesh Vikal ◽  
Harleen Kaur ◽  
Lalit Pal ◽  
Kirandeep Kaur ◽  
...  
Keyword(s):  
Zea Mays ◽  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Zea Mays L ◽  
Leaf Blight ◽  
Blight Resistance ◽  
Trait Loci ◽  
Southern Leaf Blight

scholarly journals Identification of Quantitative Trait Loci for Resistance to Southern Leaf Blight and Days to Anthesis in Two Maize Recombinant Inbred Line Populations

2008 ◽  
Vol 98 (3) ◽  
pp. 315-320 ◽  
Author(s):  
P. J. Balint-Kurti ◽  
J. C. Zwonitzer ◽  
M. E. Pè ◽  
G. Pea ◽  
M. Lee ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Inbred Line ◽  
Recombinant Inbred Line ◽  
Quantitative Trait ◽  
Recombinant Inbred ◽  
Leaf Blight ◽  
Phenotypic Correlation ◽  
Resistance Qtl ◽  
Trait Loci ◽  
Southern Leaf Blight

The genetic architecture underlying resistance in maize to southern leaf blight (SLB) caused by Cochliobolus heterostrophus race O is not well understood. The objective of this study was to identify loci contributing to SLB resistance in two recombinant inbred line populations and to compare these to SLB resistance loci in other populations. The two populations used were derived from crosses between maize inbred lines H99 and B73 (HB population–142 lines) and between B73 and B52 (BB population–186 lines). They were evaluated for SLB resistance and for days from planting to anthesis (DTA) in 2005 and 2006. Two replications arranged as randomized complete blocks were assessed in each year for each population. Entry mean heritabilities for disease resistance were high for both populations (0.876 and 0.761, respectively). Quantitative trait loci (QTL) for SLB resistance were identified in bins 3.04 (two QTL), 6.01, and 8.05 in the HB population and in bin 2.07 in the BB population. No overlap of DTA and SLB resistance QTL was observed, nor was there any phenotypic correlation between the traits. A comparison of the results of all published SLB resistance QTL studies suggested that bins 3.04 and 6.01 are ‘hotspots’ for SLB resistance QTL.

scholarly journals Analysis of Quantitative Trait Loci for Resistance to Southern Leaf Blight in Juvenile Maize

2006 ◽  
Vol 96 (3) ◽  
pp. 221-225 ◽  
Author(s):  
P. J. Balint-Kurti ◽  
M. L. Carson
Keyword(s):  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Quantitative Resistance ◽  
Recombinant Inbred Lines ◽  
Inbred Lines ◽  
Leaf Blight ◽  
Growth Stages ◽  
Trait Loci ◽  
Southern Leaf Blight ◽  
Juvenile Plants

A set of 192 maize recombinant inbred lines (RILs), derived from a cross between the inbred lines Mo17 and B73, were evaluated as 3-week-old seedlings in the greenhouse for resistance to southern leaf blight, caused by Cochliobolus heterostrophus race O. Six significant (LOD >3.1) quantitative trait loci (QTL) were identified for disease resistance, located on chromosomes 1, 2, 3, 6, 7, and 8. Results were compared with a previous study that had used the same RIL population and pathogen isolate, but had examined resistance in mature rather than juvenile plants. There was a very weak but significant correlation between the overall resistance phenotypes of the RILs scored as mature and juvenile plants. Two QTL were found in similar positions on chromosomes 1 and 3 at both growth stages. Other QTL were specific to one growth stage or the other. Twenty-three of these RILs, together with the parental lines, were inoculated in the greenhouse with four C. heterostrophus isolates. Results indicated that the quantitative resistance observed was largely isolate non-specific.

scholarly journals Identification of Quantitative Trait Loci for Resistance to Southern Leaf Blight and Days to Anthesis in a Maize Recombinant Inbred Line Population

2006 ◽  
Vol 96 (10) ◽  
pp. 1067-1071 ◽  
Author(s):  
P. J. Balint-Kurti ◽  
M. D. Krakowsky ◽  
M. P. Jines ◽  
L. A. Robertson ◽  
T. L. Molnár ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Inbred Line ◽  
Recombinant Inbred Line ◽  
Recombinant Inbred Line Population ◽  
Quantitative Trait ◽  
Recombinant Inbred ◽  
Leaf Blight ◽  
Resistance Qtl ◽  
Trait Loci ◽  
Southern Leaf Blight

A recombinant inbred line population derived from a cross between the maize lines NC300 (resistant) and B104 (susceptible) was evaluated for resistance to southern leaf blight (SLB) disease caused by Cochliobolus heterostrophus race O and for days to anthesis in four environments (Clayton, NC, and Tifton, GA, in both 2004 and 2005). Entry mean and average genetic correlations between disease ratings in different environments were high (0.78 to 0.89 and 0.9, respectively) and the overall entry mean heritability for SLB resistance was 0.89. When weighted mean disease ratings were fitted to a model using multiple interval mapping, seven potential quantitative trait loci (QTL) were identified, the two strongest being on chromosomes 3 (bin 3.04) and 9 (bin 9.03–9.04). These QTL explained a combined 80% of the phenotypic variation for SLB resistance. Some time-point-specific SLB resistance QTL were also identified. There was no significant correlation between disease resistance and days to anthesis. Six putative QTL for time to anthesis were identified, none of which coincided with any SLB resistance QTL.

Targeted discovery of quantitative trait loci for resistance to northern leaf blight and other diseases of maize

2011 ◽  
Vol 123 (2) ◽  
pp. 307-326 ◽  
Author(s):  
Chia-Lin Chung ◽  
Jesse Poland ◽  
Kristen Kump ◽  
Jacqueline Benson ◽  
Joy Longfellow ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Leaf Blight ◽  
Northern Leaf Blight ◽  
Trait Loci

scholarly journals Identification of Quantitative Trait Loci Relating to Flowering Time, Flag Leaf and Awn Characteristics in a Novel Triticum dicoccum Mapping Population

Plants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 829
Author(s):  
Tally I.C. Wright ◽  
Angela C. Burnett ◽  
Howard Griffiths ◽  
Maxime Kadner ◽  
James S. Powell ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Quantitative Trait Loci ◽  
Flowering Time ◽  
Quantitative Trait ◽  
Marker Assisted Selection ◽  
Mapping Population ◽  
Flag Leaf ◽  
Snp Array ◽  
Leaf Length ◽  
Trait Loci

Tetraploid landraces of wheat harbour genetic diversity that could be introgressed into modern bread wheat with the aid of marker-assisted selection to address the genetic diversity bottleneck in the breeding genepool. A novel bi-parental Triticum turgidum ssp. dicoccum Schrank mapping population was created from a cross between two landrace accessions differing for multiple physiological traits. The population was phenotyped for traits hypothesised to be proxies for characteristics associated with improved photosynthesis or drought tolerance, including flowering time, awn length, flag leaf length and width, and stomatal and trichome density. The mapping individuals and parents were genotyped with the 35K Wheat Breeders’ single nucleotide polymorphism (SNP) array. A genetic linkage map was constructed from 104 F4 individuals, consisting of 2066 SNPs with a total length of 3295 cM and an average spacing of 1.6 cM. Using the population, 10 quantitative trait loci (QTLs) for five traits were identified in two years of trials. Three consistent QTLs were identified over both trials for awn length, flowering time and flag leaf width, on chromosomes 4A, 7B and 5B, respectively. The awn length and flowering time QTLs correspond with the major loci Hd and Vrn-B3, respectively. The identified marker-trait associations could be developed for marker-assisted selection, to aid the introgression of diversity from a tetraploid source into modern wheat for potential physiological trait improvement.

scholarly journals Comparison of GWAS models to identify non-additive genetic control of flowering time in sunflower hybrids

2017 ◽  
Author(s):  
Fanny Bonnafous ◽  
Ghislain Fievet ◽  
Nicolas Blanchet ◽  
Marie-Claude Boniface ◽  
Sébastien Carrère ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Flowering Time ◽  
Genetic Control ◽  
Quantitative Trait ◽  
Complex Traits ◽  
Association Studies ◽  
Additive Models ◽  
Genome Wide Association Studies ◽  
Trait Loci ◽  
Genomic Regions

AbstractGenome-wide association studies are a powerful and widely used tool to decipher the genetic control of complex traits. One of the main challenges for hybrid crops, such as maize or sunflower, is to model the hybrid vigor in the linear mixed models, considering the relatedness between individuals. Here, we compared two additive and three non-additive association models for their ability to identify genomic regions associated with flowering time in sunflower hybrids. A panel of 452 sunflower hybrids, corresponding to incomplete crossing between 36 male lines and 36 female lines, was phenotyped in five environments and genotyped for 2,204,423 SNPs. Intra-locus effects were estimated in multi-locus models to detect genomic regions associated with flowering time using the different models. Thirteen quantitative trait loci were identified in total, two with both model categories and one with only non-additive models. A quantitative trait loci on LG09, detected by both the additive and non-additive models, is located near a GAI homolog and is presented in detail. Overall, this study shows the added value of non-additive modeling of allelic effects for identifying genomic regions that control traits of interest and that could participate in the heterosis observed in hybrids.

Syntenic quantitative trait loci and genomic divergence for Sclerotinia resistance and flowering time in Brassica napus

2019 ◽  
Vol 61 (1) ◽  
pp. 75-88 ◽  
Author(s):  
Fengqi Zhang ◽  
Junyan Huang ◽  
Minqiang Tang ◽  
Xiaohui Cheng ◽  
Yueying Liu ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Quantitative Trait Loci ◽  
Flowering Time ◽  
Quantitative Trait ◽  
Genomic Divergence ◽  
Trait Loci
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