DEVELOPMENT OF A C. CARDUNCULUS LINKAGE MAP BASED ON SRAP, SSR, SNP MARKERS AND LOCALIZATION OF PHENOTYPIC TRAITS

2013 ◽  
pp. 139-143
Author(s):  
E. Martin ◽  
E. Acquaviva ◽  
V. Cravero ◽  
E. Portis ◽  
D. Scaglione ◽  
...  
2018 ◽  
Author(s):  
David T. Ashton ◽  
Peter A. Ritchie ◽  
Maren Wellenreuther

ABSTRACTCharacterizing the genetic variation underlying phenotypic traits is a central objective in biological research. This research has been hampered in the past by the limited genomic resources available for most non-model species. However, recent advances in sequencing technology and related genotyping methods are rapidly changing this. Here we report the use of genome-wide SNP data from the ecologically and commercially important marine fish species Chrysophrys auratus (snapper) to 1) construct the first linkage map for this species, 2) scan for growth QTLs, and 3) search for candidate genes in the surrounding QTL regions. The newly constructed linkage map contained ~11K SNP markers and is the densest map to date in the fish family Sparidae. Comparisons with available genome scaffolds indicated that overall marker placement was strongly correlated between the scaffolds and linkage map (R = 0.7), but at fine scales (< 5 cM) there were some precision limitations. Of the 24 linkage groups, which reflect the 24 chromosomes of this species, three were found to contain QTLs with genome-wide significance for growth-related traits. A scan for 13 known candidate growth genes located the genes for growth hormone, parvalbumin, and myogenin within 13.2, 2.6, and 5.0 cM of these genome-wide significant QTLs, respectively. The linkage map and QTLs found in this study will advance the investigation of genome structure and selective breeding in snapper.


2020 ◽  
Vol 12 (11) ◽  
pp. 1953-1960
Author(s):  
Andrey A Yurchenko ◽  
Hans Recknagel ◽  
Kathryn R Elmer

Abstract Squamate reptiles exhibit high variation in their phenotypic traits and geographical distributions and are therefore fascinating taxa for evolutionary and ecological research. However, genomic resources are very limited for this group of species, consequently inhibiting research efforts. To address this gap, we assembled a high-quality genome of the common lizard, Zootoca vivipara (Lacertidae), using a combination of high coverage Illumina (shotgun and mate-pair) and PacBio sequencing data, coupled with RNAseq data and genetic linkage map generation. The 1.46-Gb genome assembly has a scaffold N50 of 11.52 Mb with N50 contig size of 220.4 kb and only 2.96% gaps. A BUSCO analysis indicates that 97.7% of the single-copy Tetrapoda orthologs were recovered in the assembly. In total, 19,829 gene models were annotated to the genome using a combination of ab initio and homology-based methods. To improve the chromosome-level assembly, we generated a high-density linkage map from wild-caught families and developed a novel analytical pipeline to accommodate multiple paternity and unknown father genotypes. We successfully anchored and oriented almost 90% of the genome on 19 linkage groups. This annotated and oriented chromosome-level reference genome represents a valuable resource to facilitate evolutionary studies in squamate reptiles.


2020 ◽  
Vol 11 (87) ◽  
Author(s):  
Zhanna Bazyliuk ◽  

The study of the human genome makes it possible to use genetic information to identify individual traits, diagnosis of diseases and forecasting and prevention of their development, promotes a personal approach when choosing treatment methods; population research, ethnogenesis and evolutionary processes. Introduction of DNA sequencing methods in domestic genetic fingerprinting will contribute to a more informative establishment of human genetic traits. The main purpose of molecular genetic research is to establish the genetic features of missing people, their relatives, to conduct paternity, to identify traces of biological origin and their identification. This article talks about the gradual development of DNA sequencing technology, which is conventionally divided into three types. The first type includes sequencing using capillary electrophoresis and pyrosequencing. The second type is high-throughput pyrosequencing, semiconductor, cyclic ligase, and the use of fluorescently labeled precursors, based on the sequencing of millions of DNA fragments simultaneously. The third stage includes methods that do not require prior sample preparation. These are methods of nanoporous sequencing, sequencing of one molecule, one-molecular sequencing. Today, each of the sequencing methods is aimed at performing different tasks. A number of methods are promising in the field of molecular-genetic examination. In world jurisprudence, sequencing is implemented mainly with the help of devices - Illumina’s, MiSeq FGx, Ion Torrent PGM from ThermoFisher and Ion S5. Research in forensic expertise of single nucleotide polymorphisms (SNP), sequencing of STR-loci and mitochondrial DNA, STR-loci and SNP-markers of the Y chromosome, will provide a high level of information, determination of human phenotypic traits, the possibility of establishing genetic traits from significantly degraded DNA. This article deals with modern problems of identification of human genetic traits and the prospect of introduction of the newest methods of sequencing for their qualitative and complete establishment.


2006 ◽  
Vol 2 (3) ◽  
pp. 435-438 ◽  
Author(s):  
Niclas Backström ◽  
Anna Qvarnström ◽  
Lars Gustafsson ◽  
Hans Ellegren

Population-based mapping approaches are attractive for tracing the genetic background to phenotypic traits in wild species, given that it is often difficult to gather extensive and well-defined pedigrees needed for quantitative trait locus analysis. However, the feasibility of association or hitch-hiking mapping is dependent on the degree of linkage disequilibrium (LD) in the population, on which there is yet limited information for wild species. Here we use single nucleotide polymorphism (SNP) markers from 23 genes in a recently established linkage map of the Z chromosome of the collared flycatcher, to study the extent of LD in a natural bird population. In most but not all cases we find SNPs within the same intron (less than 500 bp) to be in perfect LD. However, LD then decays to background level at a distance 1 cM or 400–500 kb. Although LD seems more extensive than in other species, if the observed pattern is representative for other regions of the genome and turns out to be a general feature of natural bird populations, dense marker maps might be needed for genome scans aimed at identifying association between marker and trait loci.


2018 ◽  
Author(s):  
André Ricardo Oliveira Conson ◽  
Cristiane Hayumi Taniguti ◽  
Rodrigo Rampazo Amadeu ◽  
Isabela Aparecida Araújo Andreotti ◽  
Livia Moura de Souza ◽  
...  

AbstractRubber tree (Hevea brasiliensis) cultivation is the main source of natural rubber worldwide and has been extended to areas with suboptimal climates and lengthy drought periods; this transition affects growth and latex production. High-density genetic maps with reliable markers support precise mapping of quantitative trait loci (QTL), which can help reveal the complex genome of the species, provide tools to enhance molecular breeding, and shorten the breeding cycle. In this study, QTL mapping of the stem diameter, tree height, and number of whorls was performed for a full-sibling population derived from a GT1 and RRIM701 cross. A total of 225 simple sequence repeats (SSRs) and 186 single-nucleotide polymorphism (SNP) markers were used to construct a base map with 18 linkage groups and to anchor 671 SNPs from genotyping by sequencing (GBS) to produce a very dense linkage map with small intervals between loci. The final map was composed of 1,079 markers, spanned 3,779.7 cM with an average marker density of 3.5 cM, and showed collinearity between markers from previous studies. Significant variation in phenotypic characteristics was found over a 59-month evaluation period with a total of 38 QTLs being identified through a composite interval mapping method. Linkage group 4 showed the greatest number of QTLs (7), with phenotypic explained values varying from 7.67% to 14.07%. Additionally, we estimated segregation patterns, dominance, and additive effects for each QTL. A total of 53 significant effects for stem diameter were observed, and these effects were mostly related to additivity in the GT1 clone. Associating accurate genome assemblies and genetic maps represents a promising strategy for identifying the genetic basis of phenotypic traits in rubber trees. Then, further research can benefit from the QTLs identified herein, providing a better understanding of the key determinant genes associated with growth of Hevea brasiliensis under limiting water conditions.


2017 ◽  
Vol 1 (3) ◽  
pp. 80-89 ◽  
Author(s):  
Masum Akond ◽  
Shiming Liu ◽  
Lauren Schoener ◽  
James A. Anderson ◽  
Stella K. Kantartzi ◽  
...  

This study reports a high density genetic linkage map based on the ‘Maryland 96-5722’ by ‘Spencer’ recombinant inbred line (RIL) population of soybean [Glycine max (L.) Merr.] and constructed exclusively with single nucleotide polymorphism (SNP) markers. The Illumina Infinium SoySNP6K BeadChip genotyping array produced 5,376 SNPs in the mapping population, with a 96.75% success rate. Significant level of goodness-of-fit for each locus was tested based on the observed vs. expected ratio (1:1). Out of 5,376 markers, 1,465 SNPs fit the 1:1 segregation rate having ≤20% missing data plus heterozygosity among the RILs. Among this 1,456 just 657 were polymorphic between the parents DNAs tested. These 657 SNPs were mapped using the JoinMap 4.0 software and 550 SNPs were distributed on 16 linkage groups (LGs) among the 20 chromosomes of the soybean genome. The total map length was just 201.57 centiMorgans (cM) with an average marker density of 0.37 cM. This is one of the high density SNP-based genetic linkage maps of soybean that will be used by the scientific community to map quantitative trait loci (QTL) and identify candidate genes for important agronomic traits in soybean.


2019 ◽  
Vol 144 (5) ◽  
pp. 352-362
Author(s):  
Vanessa E.T.M. Ashworth ◽  
Haofeng Chen ◽  
Carlos L. Calderón-Vázquez ◽  
Mary Lu Arpaia ◽  
David N. Kuhn ◽  
...  

The glossy, green-fleshed fruit of the avocado (Persea americana) has been the object of human selection for thousands of years. Recent interest in healthy nutrition has singled out the avocado as an excellent source of several phytonutrients. Yet as a sizeable, slow-maturing tree crop, it has been largely neglected by genetic studies, owing to a long breeding cycle and costly field trials. We use a small, replicated experimental population of 50 progeny, grown at two locations in two successive years, to explore the feasibility of developing a dense genetic linkage map and to implement quantitative trait locus (QTL) analysis for seven phenotypic traits. Additionally, we test the utility of candidate-gene single-nucleotide polymorphisms developed to genes from biosynthetic pathways of phytonutrients beneficial to human health. The resulting linkage map consisted of 1346 markers (1044.7 cM) distributed across 12 linkage groups. Numerous markers on Linkage Group 10 were associated with a QTL for flowering type. One marker on Linkage Group 1 tracked a QTL for β-sitosterol content of the fruit. A region on Linkage Group 3 tracked vitamin E (α-tocopherol) content of the fruit, and several markers were stable across both locations and study years. We argue that the pursuit of linkage mapping and QTL analysis is worthwhile, even when population size is small.


2021 ◽  
Author(s):  
Fahad Alotaibi ◽  
Rahmah N. Al-Qthanin ◽  
Maha Aljabri ◽  
Mohammed Albaqami ◽  
Salah Abou-Elwafa

Abstract Soil salinity is a major environmental stress that adversely impacts the growth, development, productivity and quality of crop species, in particular, in arid and semi-arid regions. Identification of chromosomal regions associated with agronomic traits under salinity stress is crucial for improving salinity tolerance in wheat. GWAS and structure analyses were employed to evaluate 289 elite lines of the Wheat Association Mapping Initiative (WAMI) population under low (LS) and high (HS) salinity conditions using 15,737 SNP markers and seven agronomical traits. Evaluated genotypes responded differently to the different environments in all measured phenotypic traits, highlighting genetic diversity within the WAMI population in response to salt stress. Heritability degree ranged from moderate (37%) to high (88%). GWAS identified 118 and 120 significant associations between SNP markers and seven evaluated phenotypic traits under LS and HS conditions, respectively. Significant association of some markers with more than one phenotypic trait was observed, indicating possible pleiotropic or indirect effects. A high degree of significant linkage disequilibrium (> 52%) was observed among SNP markers on different chromosomes indicating epistatic interaction. The salt stress index (STI) exhibited a positive significant correlation to grain yield per plant (GYP) under both LS and HS conditions (R2 = 0.851–0.856). A linear regression between STI and GYP under HS conditions (GYPs) was identified, suggest that STI is the best tolerance index for predicting high yielding-genotypes. The results present the WAMI population as a valuable source for improving yield potential for salt tolerance in wheat. Furthermore, our findings emphasize that GWAS is a powerful tool in promoting wheat breeding through accurate identification of molecular markers significantly associated with agronomic traits, which is essential for marker-assisted breeding.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259883
Author(s):  
Seltene Abady ◽  
Hussein Shimelis ◽  
Pasupuleti Janila ◽  
Shasidhar Yaduru ◽  
Admire I. T. Shayanowako ◽  
...  

Profiling the genetic composition and relationships among groundnut germplasm collections is essential for the breeding of new cultivars. The objectives of this study were to assess the genetic diversity and population structure among 100 improved groundnut genotypes using agronomic traits and high-density single nucleotide polymorphism (SNP) markers. The genotypes were evaluated for agronomic traits and drought tolerance at the International Crop Research Institute for the Semi-Arid Tropics (ICRISAT)/India across two seasons. Ninety-nine of the test genotypes were profiled with 16363 SNP markers. Pod yield per plant (PY), seed yield per plant (SY), and harvest index (HI) were significantly (p < 0.05) affected by genotype × environment interaction effects. Genotypes ICGV 07222, ICGV 06040, ICGV 01260, ICGV 15083, ICGV 10143, ICGV 03042, ICGV 06039, ICGV 14001, ICGV 11380, and ICGV 13200 ranked top in terms of pod yield under both drought-stressed and optimum conditions. PY exhibited a significant (p ≤ 0.05) correlation with SY, HI, and total biomass (TBM) under both test conditions. Based on the principal component (PC) analysis, PY, SY, HSW, shelling percentage (SHP), and HI were allocated in PC 1 and contributed to the maximum variability for yield under the two water regimes. Hence, selecting these traits could be successful for screening groundnut genotypes under drought-stressed and optimum conditions. The model-based population structure analysis grouped the studied genotypes into three sub-populations. Dendrogram for phenotypic and genotypic also grouped the studied 99 genotypes into three heterogeneous clusters. Analysis of molecular variance revealed that 98% of the total genetic variation was attributed to individuals, while only 2% of the total variance was due to variation among the subspecies. The genetic distance between the Spanish bunch and Virginia bunch types ranged from 0.11 to 0.52. The genotypes ICGV 13189, ICGV 95111, ICGV 14421, and ICGV 171007 were selected for further breeding based on their wide genetic divergence. Data presented in this study will guide groundnut cultivar development emphasizing economic traits and adaptation to water-limited agro-ecologies, including in Ethiopia.


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