scholarly journals Detection of Quantitative Trait Loci (QTL) associated with the spring regrowth vigor trait in alfalfa (Medicago sativa L.)

2020 ◽  
Author(s):  
Xueqian Jiang ◽  
Fan Zhang ◽  
Zhen Wang ◽  
Ruicai Long ◽  
Mingna Li ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Medicago Sativa ◽  
Quantitative Trait ◽  
Female Parent ◽  
Genotyping By Sequencing ◽  
Snp Markers ◽  
Phenotypic Data ◽  
Single Nucleotide ◽  
Trait Loci ◽  
Medicago Sativa L

Abstract Background: Alfalfa ( Medicago sativa L.) is a perennial forage legume with a reputation as being the “queen of forage”. Spring regrowth vigor refers to the process of perennial alfalfa returning to growth after winter survival. The objective of this research was to identify candidate genes significantly associated with spring regrowth vigor.Results: We used a tetraploid alfalfa F1 population comprised of 392 progenies to identify quantitative trait loci (QTL) that control this trait. The F1 population phenotypic data were collected using a total of three environmental phenotypic data. The mapping population was genotyped using Genotyping-by-sequencing (GBS), and linkage maps were developed based on single nucleotide polymorphism (SNP) markers. Fifteen significant QTL for spring regrowth vigor were detected in both parents. Five QTL were identified in the male genetic map, while ten QTL were identified in the female. Four QTL were located on homolog 7D of the male parent, and two QTL were colocalized. Five QTL were mapped on homolog 6D of the female parent, and two QTL were colocalized.Conclusions: The QTL presented in this study can be used to improve the efficiency of alfalfa breeding programs and provide valuable resources for the genetic improvement of alfalfa using marker-assisted selection (MAS).β These authors contributed equally to this research. *Correspondence:Junmei [email protected]

scholarly journals Mapping Quantitative Trait Loci Associated With Graft (In)Compatibility in Apricot (Prunus armeniaca L.)

2021 ◽  
Vol 12 ◽  
Author(s):  
Ana Pina ◽  
Patricia Irisarri ◽  
Pilar Errea ◽  
Tetyana Zhebentyayeva
Keyword(s):  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Woody Plants ◽  
Molecular Mechanisms ◽  
Prunus Persica ◽  
Snp Markers ◽  
Genetic Maps ◽  
Phenotypic Data ◽  
Trait Loci ◽  
Genomic Regions

Graft incompatibility (GI) between the most popular Prunus rootstocks and apricot cultivars is one of the major problems for rootstock usage and improvement. Failure in producing long-leaving healthy grafts greatly affects the range of available Prunus rootstocks for apricot cultivation. Despite recent advances related to the molecular mechanisms of a graft-union formation between rootstock and scion, information on genetic control of this trait in woody plants is essentially missing because of a lack of hybrid crosses, segregating for the trait. In this study, we have employed the next-generation sequencing technology to generate the single-nucleotide polymorphism (SNP) markers and construct parental linkage maps for an apricot F1 population “Moniqui (Mo)” × “Paviot (Pa)” segregating for ability to form successful grafts with universal Prunus rootstock “Marianna 2624”. To localize genomic regions associated with this trait, we genotyped 138 individuals from the “Mo × Pa” cross and constructed medium-saturated genetic maps. The female “Mo” and male “Pa” maps were composed of 557 and 501 SNPs and organized in eight linkage groups that covered 780.2 and 690.4 cM of genetic distance, respectively. Parental maps were aligned to the Prunus persica v2.0 genome and revealed a high colinearity with the Prunus reference map. Two-year phenotypic data for characters associated with unsuccessful grafting such as necrotic line (NL), bark and wood discontinuities (BD and WD), and an overall estimate of graft (in)compatibility (GI) were collected for mapping quantitative trait loci (QTLs) on both parental maps. On the map of the graft-compatible parent “Pa”, two genomic regions on LG5 (44.9–60.8 cM) and LG8 (33.2–39.2 cM) were associated with graft (in)compatibility characters at different significance level, depending on phenotypic dataset. Of these, the LG8 QTL interval was most consistent between the years and supported by two significant and two putative QTLs. To our best knowledge, this is the first report on QTLs for graft (in)compatibility in woody plants. Results of this work will provide a valuable genomic resource for apricot breeding programs and facilitate future efforts focused on candidate genes discovery for graft (in)compatibility in apricot and other Prunus species.

scholarly journals Time-Related Mapping of Quantitative Trait Loci Underlying Tiller Number in Rice

Genetics ◽  
1999 ◽  
Vol 151 (1) ◽  
pp. 297-303 ◽  
Author(s):  
Wei-Ren Wu ◽  
Wei-Ming Li ◽  
Ding-Zhong Tang ◽  
Hao-Ran Lu ◽  
A J Worland
Keyword(s):  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Composite Interval Mapping ◽  
Interval Mapping ◽  
Tiller Number ◽  
Multiple Trait ◽  
Phenotypic Data ◽  
Recombinant Inbred Population ◽  
Trait Loci ◽  
Final Observation

Abstract Using time-related phenotypic data, methods of composite interval mapping and multiple-trait composite interval mapping based on least squares were applied to map quantitative trait loci (QTL) underlying the development of tiller number in rice. A recombinant inbred population and a corresponding saturated molecular marker linkage map were constructed for the study. Tiller number was recorded every 4 or 5 days for a total of seven times starting at 20 days after sowing. Five QTL were detected on chromosomes 1, 3, and 5. These QTL explained more than half of the genetic variance at the final observation. All the QTL displayed an S-shaped expression curve. Three QTL reached their highest expression rates during active tillering stage, while the other two QTL achieved this either before or after the active tillering stage.

scholarly journals A Fine mapping quantitative trait loci that underlie resistance to soybean sudden death syndrome using NILs and SNPs.

2018 ◽  
pp. 583-591
Author(s):  
Yi Chen Lee ◽  
M Javed Iqbal ◽  
Victor N Njiti ◽  
Stella Kantartzi ◽  
David A. Lightfoot
Keyword(s):  
Quantitative Trait Loci ◽  
Sudden Death ◽  
Candidate Genes ◽  
Quantitative Trait ◽  
Soybean Cyst Nematode ◽  
Snp Markers ◽  
Sudden Death Syndrome ◽  
Isogenic Line ◽  
Trait Loci ◽  
Glycine Max L

Soybean (Glycine max (L.) Merr.) cultivars differ in their resistance to sudden death syndrome (SDS), caused by Fusarium virguliforme. Breeding for improving SDS response has been challenging, due to interactions among the 18-42 known resistance loci. Four quantitative trait loci (QTL) for resistance to SDS (cqRfs–cqRfs3) were clustered within 20 cM of the rhg1 locus underlying resistance to soybean cyst nematode (SCN) on Chromosome (Chr.) 18. Another locus on Chr. 20 (cqRfs5) was reported to interact with this cluster. The aims here were to compare the inheritance of resistance to SDS in a near isogenic line (NIL) population that was fixed for resistance to SCN but segregated at two of the four loci (cqRfs1 and cqRfs) for SDS resistance; to examine the interaction with the locus on Chr. 20; and to identify candidate genes underlying QTL. Used were; a NIL population derived from residual heterozygosity in an F5:7 recombinant inbred line EF60 (lines 1-38); SDS response data from two locations and years; four segregating microsatellite and 1,500 SNP markers. Polymorphic regions were found from 2,788 Kbp to 8,938 Kbp on Chr. 18 and 33,100 Kbp to 34,943 Kbp on Chr. 20 that were significantly (0.005 < P > 0.0001) associated with resistance to SDS. The QTL fine maps suggested that the two loci on Chr. 18 were three loci (cqRfs1, cqRfs, and cqRfs19). Candidate genes were inferred.  An epistatic interaction was inferred between Chr. 18 and Chr. 20 loci. Therefore, SDS resistance QTL were both complex and interacting.

Detection of quantitative trait loci for wheat (Triticum aestivum L.) heading and flowering date

2019 ◽  
Vol 157 (1) ◽  
pp. 20-30
Author(s):  
C. H. Zhao ◽  
H. Sun ◽  
C. Liu ◽  
G. M. Yang ◽  
X. J. Liu ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Genetic Relationships ◽  
Heading Date ◽  
Female Parent ◽  
Triticum Aestivum L ◽  
Wheat Breeding ◽  
Yield Potential ◽  
Flowering Date ◽  
Trait Loci

AbstractHeading date (HD) and flowering date (FD) are critical for yield potential and stability, so understanding their genetic foundation is of great significance in wheat breeding. Three related recombinant inbred line populations with a common female parent were developed to identify quantitative trait loci (QTL) for HD and FD in four environments. In total, 25 putative additive QTL and 20 pairwise epistatic effect QTL were detected in four environments. The additive QTL were distributed across 17 wheat chromosomes. Of these, QHd-1A, QHd-1D, QHd-2B, QHd-3B, QHd-4A, QHd-4B and QHd-6D were major and stable QTL for HD. QFd-1A, QFd-2B, QFd-4A and QFd-4B were major and stable QTL for FD. In addition, an epistatic interaction test showed that epistasis played important roles in controlling wheat HD and FD. Genetic relationships between HD/FD and five yield-related traits (YRTs) were characterized and ten QTL clusters (C1–C10) simultaneously controlling YRTs and HD/FD were identified. The present work laid a genetic foundation for improving yield potential in wheat molecular breeding programmes.

The TG5 thyroglobulin gene test for a marbling quantitative trait loci evaluated in feedlot cattle

2004 ◽  
Vol 44 (7) ◽  
pp. 669 ◽  
Author(s):  
W. Barendse ◽  
R. Bunch ◽  
M. Thomas ◽  
S. Armitage ◽  
S. Baud ◽  
...  
Keyword(s):  
Single Nucleotide Polymorphism ◽  
Quantitative Trait Loci ◽  
Dna Sequence ◽  
Dna Markers ◽  
Quantitative Trait ◽  
Allelic Association ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Trait Loci ◽  
Thyroglobulin Gene

The TG5 (thyroglobulin 5′ leader sequence) single nucleotide polymorphism has been associated with marbling in cattle fed for periods longer than 250 days. To test whether the association could be detected in diverse cattle, fed for less than 250 days, and to measure the size of the effect, we sampled 1750 cattle from the AMH Toowoomba feedlot. These cattle were sampled on 28 separate days, over 9 months. Their marbling scores covered the complete range. We found that the TG5 single nucleotide polymorphism was associated with marbling scores (P<0.05) and estimated that TG5 genotypes explained 6.5% of the residual deviance for the marbling phenotype. We also found that the '3' allele was more frequent in animals with higher marbling scores. The consistency of the allelic association between studies and, in particular, the association found in diverse cattle, indicate that the TG5 polymorphism can be used as a breeding tool and possibly a feedlot entry tool. To estimate the size of the genetic region in which the marbling quantitative trait loci are located, we tested the nearby DNA markers CSSM66 and BMS1747. These do not show allelic associations to marbling. The consistency of the allelic association between studies, the lack of association to nearby DNA markers and the complementary information on gene action of genes near Thyroglobulin suggest that DNA sequence variations, in or near the Thyroglobulin gene sequence, are the likely causes for the marbling quantitative trait loci. Further studies of single nucleotide polymorphism in and near the Thyroglobulin DNA sequence should allow causal mutations for the effect to be identified.

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