scholarly journals Genetic Mapping by Sequencing More Precisely Detects Loci Responsible for Anaerobic Germination Tolerance in Rice

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 705
Author(s):  
John Carlos I. Ignacio ◽  
Maricris Zaidem ◽  
Carlos Casal ◽  
Shalabh Dixit ◽  
Tobias Kretzschmar ◽  
...  

Direct seeded rice (DSR) is a mainstay for planting rice in the Americas, and it is rapidly becoming more popular in Asia. It is essential to develop rice varieties that are suitable for this type of production system. ASD1, a landrace from India, possesses several traits desirable for direct-seeded fields, including tolerance to anaerobic germination (AG). To map the genetic basis of its tolerance, we examined a population of 200 F2:3 families derived from a cross between IR64 and ASD1 using the restriction site-associated DNA sequencing (RAD-seq) technology. This genotyping platform enabled the identification of 1921 single nucleotide polymorphism (SNP) markers to construct a high-resolution genetic linkage map with an average interval of 0.9 cM. Two significant quantitative trait loci (QTLs) were detected on chromosomes 7 and 9, qAG7 and qAG9, with LOD scores of 7.1 and 15.0 and R2 values of 15.1 and 29.4, respectively. Here, we obtained more precise locations of the QTLs than traditional simple sequence repeat and low-density SNP genotyping methods and may help further dissect the genetic factors of these QTLs.

2020 ◽  
Vol 56 (No. 2) ◽  
pp. 62-70 ◽  
Author(s):  
Shahril Ab Razak ◽  
Nor Helwa Ezzah Nor Azman ◽  
Rahiniza Kamaruzaman ◽  
Shamsul Amri Saidon ◽  
Muhammad Fairuz Mohd Yusof ◽  
...  

Understanding genetic diversity is a main key for crop improvement and genetic resource management. In this study, we aim to evaluate the genetic diversity of the released Malaysian rice varieties using single nucleotide polymorphism (SNP) markers. A total of 46 released Malaysian rice varieties were genotyped using 1536 SNP markers to evaluate their diversity. Out of 1536 SNPs, only 932 SNPs (60.7%) represented high quality alleles, whereas the remainder either failed to amplify or had low call rates across the samples. Analysis of the 932 SNPs revealed that a total of 16 SNPs were monomorphic. The analysis of the SNPs per chromosome revealed that the average of the polymorphic information content (PIC) value ranged from 0.173 for chromosome 12 to 0.259 for chromosome 11, with an average of 0.213 per locus. The genetic analysis of the 46 released Malaysian rice varieties using an unweighted pair group method with arithmetic mean (UPGMA) dendrogram revealed the presence of two major groups. The analysis was supported by the findings from the STRUCTURE analysis which indicated the ∆K value to be at the highest peak at K = 2, followed by K = 4. The pairwise genetic distance of the shared alleles showed that the value ranged from 0.000 (MR159–MR167) to 0.723 (MRIA–Setanjung), which suggested that MR159 and MR167 were identical, and that the highest dissimilarity was detected between MRIA 1 and Setanjung. The results of the study will be very useful for the variety identification, the proper management and conservation of the genetic resources, and the exploitation and utilisation in future breeding programmes.


2008 ◽  
Vol 133 (6) ◽  
pp. 810-818 ◽  
Author(s):  
John McCallum ◽  
Susan Thomson ◽  
Meeghan Pither-Joyce ◽  
Fernand Kenel ◽  
Andrew Clarke ◽  
...  

Bulb onion (Allium cepa L.) is a globally significant crop, but the structure of genetic variation within and among populations is poorly understood. We broadly surveyed genetic variation in a cultivated onion germplasm using simple sequence repeat (SSR) markers and sequenced regions flanking expressed sequence tag (EST)-SSRs to develop single-nucleotide polymorphism (SNP) markers. Samples from 89 inbred and open-pollinated (OP) bulb onion populations of wide geographical adaptation and four related Allium L. accessions were genotyped with 56 EST-SSR and four genomic SSR markers. Multivariate analysis of genetic distances among populations resolved long-day, short-day, and Indian populations. EST-SSR markers frequently revealed two major alleles at high frequency in OP populations. The median proportion of single-locus polymorphic loci was 0.70 in OP and landrace populations compared with 0.43 in inbred lines. Resequencing of 24 marker amplicons revealed additional SNPs in 17 (68%) and five SNP assays were developed from these, suggesting that resequencing of EST markers can readily provide SNP markers for purity testing of inbreds and other applications in Allium genetics.


Genes ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 737
Author(s):  
Maja Žulj Mihaljević ◽  
Edi Maletić ◽  
Darko Preiner ◽  
Goran Zdunić ◽  
Marijan Bubola ◽  
...  

Croatian viticulture was most extensive at the beginning of the 20th century, when about 400 varieties were in use. Autochthonous varieties are the result of spontaneous hybridization from the pre-phylloxera era and are still cultivated today on about 35 % of vineyard area, while some exist only in repositories. We present what is the most comprehensive genetic analysis of all major Croatian national repositories, with a large number of microsatellite, or simple sequence repeat (SSR) markers, and it is also the first study to apply single nucleotide polymorphism (SNP) markers. After 212 accessions were fingerprinted, 95 were classified as unique to Croatian germplasm. Genetic diversity of Croatian germplasm is rather high considering its size. SNP markers proved useful for fingerprinting but less informative and practical than SSRs. Analysis of the genetic structure showed that Croatian germplasm is predominantly part of the Balkan grape gene pool. A high number of admixed varieties and synonyms is a consequence of complex pedigrees and migrations. Parentage analysis confirmed 24 full parentages, as well as 113 half-kinships. Unexpectedly, several key genitors could not be detected within the present Croatian germplasm. The low number of reconstructed parentages (19%) points to severe genetic erosion and stresses the importance of germplasm repositories.


Genome ◽  
2020 ◽  
Vol 63 (6) ◽  
pp. 319-327 ◽  
Author(s):  
E.S. Redjeki ◽  
W.K. Ho ◽  
N. Shah ◽  
O.O. Molosiwa ◽  
N.R. Ardiarini ◽  
...  

A total of 170 bambara groundnut (Vigna subterranea) accessions were evaluated using both simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers generated using genotyping-by-sequencing (GbS), of which 56 accessions were collected from West and East Java. Principal coordinate analysis (PCoA), population structure, and cluster analysis suggest that the East Java accessions could be a result of the introduction of selected West Java accessions. In addition, the current Indonesian accessions were likely introduced from Southern Africa, which would have produced a very marked founding effect such that these accessions present only a fraction of the genetic variability that exists within this species.


Euphytica ◽  
2021 ◽  
Vol 217 (4) ◽  
Author(s):  
Sang-Hyuck Park ◽  
Jodi A. Scheffler ◽  
Jeffery D. Ray ◽  
Brian E. Scheffler

AbstractCotton (Gossypium hirsutum L.) has nectar containing modified stomates called nectaries that can be located on leaves, bracts or calyces. The nectar attracts some beneficial insects such as bees, but also predatory damaging insects such as heliothines and Lygus species. There is a naturally occurring mutation that eliminates the nectar containing nectaries and makes the cotton plants less attractive to insects. The nectariless (ne) trait is associated with a double recessive mutation of two genes (ne1 and ne2) on homeologous chromosomes 12 and 26. Expression of the trait can be variable and is also affected by environmental conditions. This makes accurately selecting for the trait based on phenotype difficult. This study identified SSR and SNP markers that can be used by breeders for marker assisted selection (MAS) of the nectariless trait. DNA markers associated with the genes conditioning the trait and used for MAS, will allow cotton cultivars to be easily developed that have decreased attractiveness to insects and reduce the need for insecticides, especially those harmful to beneficial insects such as honeybees.


2012 ◽  
Vol 12 (4) ◽  
pp. 483-494 ◽  
Author(s):  
Tomas Z Ząbek ◽  
Paweł Czapla ◽  
Maciej Wnuk ◽  
Anna Lewińska ◽  
Bernadetta Oklejewicz ◽  
...  

Abstract The objective of the study was to identify single nucleotide polymorphism (SNP) genetic markers in the equine TERT gene sequence, which were used to assess the degree of differentiation between Anglo-Arabian and Hucul horses. Polymorphisms were identified by sequencing 30 amplification products representing 18000 bp of TERT sequences. Twenty-seven SNP markers were investigated, which were at genetic equilibrium. Haplotypes and genotypes were determined, and usefulness of polymorphisms for genetic studies was assessed based on minor allele frequency (MAF). Alleles characteristic of both horse breeds were identified. SNP markers with MAF > 0.18 were considered suitable for genetic analyses concerning association studies and parentage testing. In total 26 haplotypes were identified, of which three were common to the investigated horse populations. Twelve haplotypes were found only in Anglo-Arabians and 11 in Hucul horses. Identified polymorphism of TERT gene might be useful in the search for genetic basis of aging in the Equus caballus species.


2007 ◽  
Vol 4 (1) ◽  
pp. 53-56 ◽  
Author(s):  
Zhao Rui ◽  
Liu Zhen-Zhen ◽  
Xu Gui-Yun ◽  
Yang Ning

AbstractThe oocyan (O) gene determines blue shell pigmentation of domesticated chicken. The O locus is closely linked to ALEV1 on chromosome 1 with a genetic distance of 2.3 cM. Blue eggshells contain a protoporphyrin, biliverdin and zinc biliverdin chelating complex, which belongs to the porphyrin metabolic pathway. A bio-informatic approach was first used to BLAST for the genes of the enzymes in the porphyrin pathway; no gene was detected to specify the O locus. Due to a limited number of simple sequence repeat (SSR) markers around the O locus, polymerase chain reaction–single-strand conformational polymorphism (PCR-SSCP) was then employed to search for candidate single nucleotide polymorphism (SNP) markers. The sequence bearing a marker was found to consist of two transversions at Chr1:61754089T→A and Chr1:61754175A→T, respectively. Population screening showed that 81% of homozygous blue-shelled layers (OO) were classified as AA genotype at the SNP loci, while 89% of heterozygous blue-shelled layers (Oo) were AB genotype and 93% of tinted layers (oo) were BB genotype. The results indicated that there is a close association between O locus and SNP locus, suggesting that the marker locus could be used as a molecular marker in breeding for blue-shelled chickens.


2021 ◽  
Vol 22 (7) ◽  
pp. 3477
Author(s):  
Julia Zaborowska ◽  
Bartosz Łabiszak ◽  
Annika Perry ◽  
Stephen Cavers ◽  
Witold Wachowiak

Mountain plants, challenged by vegetation time contractions and dynamic changes in environmental conditions, developed adaptations that help them to balance their growth, reproduction, survival, and regeneration. However, knowledge regarding the genetic basis of species adaptation to higher altitudes remain scarce for most plant species. Here, we attempted to identify such corresponding genomic regions of high evolutionary importance in two closely related European pines, Pinus mugo and P. uncinata, contrasting them with a reference lowland relative—P. sylvestris. We genotyped 438 samples at thousands of single nucleotide polymorphism (SNP) markers, tested their genetic differentiation and population structure followed by outlier detection and gene ontology annotations. Markers clearly differentiated the species and uncovered patterns of population structure in two of them. In P. uncinata three Pyrenean sites were grouped together, while two outlying populations constituted a separate cluster. In P. sylvestris, Spanish population appeared distinct from the remaining four European sites. Between mountain pines and the reference species, 35 candidate genes for altitude-dependent selection were identified, including such encoding proteins responsible for photosynthesis, photorespiration and cell redox homeostasis, regulation of transcription, and mRNA processing. In comparison between two mountain pines, 75 outlier SNPs were found in proteins involved mainly in the gene expression and metabolism.


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