scholarly journals Introgression of QTLs for Drought Tolerance into Farmers’ Preferred Sorghum Varieties

Agriculture ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 883
Author(s):  
Andekelile Mwamahonje ◽  
John Saviour Yaw Eleblu ◽  
Kwadwo Ofori ◽  
Tileye Feyissa ◽  
Santosh Deshpande ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Snp Markers ◽  
Stay Green ◽  
Single Nucleotide ◽  
The People ◽  
Background Population ◽  
Genotypic Analysis ◽  
Sorghum Production ◽  
Marker Assisted Backcrossing ◽  
Number Of Individuals

Sorghum is a major staple food crop for the people in semi-arid areas of Africa and Asia. Post-flowering drought is a global constraint of sorghum production. The study aimed to improve stay-green (STG) characteristics of farmer-preferred sorghum varieties in Tanzania using marker-assisted backcrossing. A total of 752 individuals representing five BC2F1 populations and their parents were genotyped using previously reported KASP markers linked with STG 3A and STG 3B quantitative trait loci (QTL). In the BC2F1 populations, the maximum number of individuals with heterozygous alleles were observed in S35*Pato background (37) whereas only seven individuals derived from the B35*Wahi parents’ background contained heterozygous alleles. Of the 30 single nucleotide polymorphism (SNP) markers, favourable alleles were observed at 18 loci in BC2F1 populations. In the BC2F1 generation, the highest (0.127 kg/panicle) grain yield was observed in the B35*NACO Mtama 1 background population. The genotypic analysis revealed the presence of favourable alleles in homozygous conditions at markers loci associated with STG 3A and STG 3B QTLs in BC2F3 populations, suggesting successful introgression of STG QTLs from the donor parents to the recurrent parents. Across water irrigation regimes, the highest (0.068 kg/panicle) mean grain weight was observed in the genotype NA316C. Therefore, our study demonstrated the utility of marker-assisted backcrossing for drought tolerance improvement of locally adapted sorghum varieties in Africa.

scholarly journals Genotyping tools and resources to assess peanut germplasm: smut-resistant landraces as a case study

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10581
Author(s):  
Alicia N. Massa ◽  
Marina Bressano ◽  
Juan H. Soave ◽  
Mario I. Buteler ◽  
Guillermo Seijo ◽  
...  
Keyword(s):  
Germplasm Collection ◽  
Snp Markers ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Genotyping Platform ◽  
Global Spread ◽  
Rnase H2 ◽  
Number Of Individuals ◽  
The U.S

Peanut smut caused by Thecaphora frezii is a severe fungal disease currently endemic to Argentina and Brazil. The identification of smut resistant germplasm is crucial in view of the potential risk of a global spread. In a recent study, we reported new sources of smut resistance and demonstrated its introgression into elite peanut cultivars. Here, we revisited one of these sources (line I0322) to verify its presence in the U.S. peanut germplasm collection and to identify single nucleotide polymorphisms (SNPs) potentially associated with resistance. Five accessions of Arachis hypogaea subsp. fastigiata from the U.S. peanut collection, along with the resistant source and derived inbred lines were genotyped with a 48K SNP peanut array. A recently developed SNP genotyping platform called RNase H2 enzyme-based amplification (rhAmp) was further applied to validate selected SNPs in a larger number of individuals per accession. More than 14,000 SNPs and nine rhAmp assays confirmed the presence of a germplasm in the U.S. peanut collection that is 98.6% identical (P < 0.01, bootstrap t-test) to the resistant line I0322. We report this germplasm with accompanying genetic information, genotyping data, and diagnostic SNP markers.

scholarly journals Drought Tolerance and Application of Marker-Assisted Selection in Sorghum

Biology ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1249
Author(s):  
Andekelile Mwamahonje ◽  
John Saviour Yaw Eleblu ◽  
Kwadwo Ofori ◽  
Santosh Deshpande ◽  
Tileye Feyissa ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Qtl Mapping ◽  
Marker Assisted Selection ◽  
Sub Saharan Africa ◽  
Stay Green ◽  
Qtl Pyramiding ◽  
Drought Tolerant ◽  
Sub Saharan ◽  
Food And Nutritional Security ◽  
Marker Assisted Backcrossing

Sorghum is an important staple food crop in drought prone areas of Sub-Saharan Africa, which is characterized by erratic rainfall with poor distribution. Sorghum is a drought-tolerant crop by nature with reasonable yield compared to other cereal crops, but such abiotic stress adversely affects the productivity. Some sorghum varieties maintain green functional leaves under post-anthesis drought stress referred to as stay-green, which makes it an important crop for food and nutritional security. Notwithstanding, it is difficult to maintain consistency of tolerance over time due to climate change, which is caused by human activities. Drought in sorghum is addressed by several approaches, for instance, breeding drought-tolerant sorghum using conventional and molecular technologies. The challenge with conventional methods is that they depend on phenotyping stay-green, which is complex in sorghum, as it is constituted by multiple genes and environmental effects. Marker assisted selection, which involves the use of DNA molecular markers to map QTL associated with stay-green, has been useful to supplement stay-green improvement in sorghum. It involves QTL mapping associated with the stay-green trait for introgression into the senescent sorghum varieties through marker-assisted backcrossing by comparing with phenotypic field data. Therefore, this review discusses mechanisms of drought tolerance in sorghum focusing on physiological, morphological, and biochemical traits. In addition, the review discusses the application of marker-assisted selection techniques, including marker-assisted backcrossing, QTL mapping, and QTL pyramiding for addressing post-flowering drought in sorghum.

scholarly journals Genome prediction accuracy of common bean via Bayesian models

2018 ◽  
Vol 48 (8) ◽  
Author(s):  
Leiri Daiane Barili ◽  
Naine Martins do Vale ◽  
Fabyano Fonseca e Silva ◽  
José Eustáquio de Souza Carneiro ◽  
Hinayah Rojas de Oliveira ◽  
...  
Keyword(s):  
Common Bean ◽  
Prediction Accuracy ◽  
Bayesian Models ◽  
Snp Markers ◽  
Genomic Information ◽  
Stay Green ◽  
Single Nucleotide ◽  
Genome Prediction ◽  
Heritability Estimation ◽  
Selection Of

ABSTRACT: We aimed to apply genomic information based on SNP (single nucleotide polymorphism) markers for the genetic evaluation of the traits “stay-green” (SG), plant architecture (PA), grain aspect (GA) and grain yield (GY) in common bean through Bayesian models. These models were compared in terms of prediction accuracy and ability for heritability estimation for each one of the mentioned traits. A total of 80 cultivars were genotyped for 377 SNP markers, whose effects were estimated by five different Bayesian models: Bayes A (BA), B (BB), C (BC), LASSO (BL) e Ridge regression (BRR). Although, prediction accuracies calculated by means of cross-validation have been similar within each trait, the BB model stood out for the trait SG, whereas the BRR was indicated for the remaining traits. The heritability estimates for the traits SG, PA, GA and GY were 0.61, 0.28, 0.32 and 0.29, respectively. In summary, the Bayesian methods applied here were effective and ease to be implemented. The used SNP markers can help in the early selection of promising genotypes, since incorporating genomic information increase the prediction accuracy of the estimated genetic merit.

scholarly journals Heteroalleles in Common Wheat: Multiple Differences between Allelic Variants of the Gli-B1 Locus

2021 ◽  
Vol 22 (4) ◽  
pp. 1832
Author(s):  
Eugene Metakovsky ◽  
Laura Pascual ◽  
Patrizia Vaccino ◽  
Viktor Melnik ◽  
Marta Rodriguez-Quijano ◽  
...  
Keyword(s):  
Common Wheat ◽  
Dna Sequences ◽  
Fragment Length Polymorphism ◽  
Snp Markers ◽  
Group Iv ◽  
Nucleotide Polymorphisms ◽  
High Genetic Diversity ◽  
Single Nucleotide ◽  
Allelic Variants ◽  
B Genome

The Gli-B1-encoded γ-gliadins and non-coding γ-gliadin DNA sequences for 15 different alleles of common wheat have been compared using seven tests: electrophoretic mobility (EM) and molecular weight (MW) of the encoded major γ-gliadin, restriction fragment length polymorphism patterns (RFLPs) (three different markers), Gli-B1-γ-gliadin-pseudogene known SNP markers (Single nucleotide polymorphisms) and sequencing the pseudogene GAG56B. It was discovered that encoded γ-gliadins, with contrasting EM, had similar MWs. However, seven allelic variants (designated from I to VII) differed among them in the other six tests: I (alleles Gli-B1i, k, m, o), II (Gli-B1n, q, s), III (Gli-B1b), IV (Gli-B1e, f, g), V (Gli-B1h), VI (Gli-B1d) and VII (Gli-B1a). Allele Gli-B1c (variant VIII) was identical to the alleles from group IV in four of the tests. Some tests might show a fine difference between alleles belonging to the same variant. Our results attest in favor of the independent origin of at least seven variants at the Gli-B1 locus that might originate from deeply diverged genotypes of the donor(s) of the B genome in hexaploid wheat and therefore might be called “heteroallelic”. The donor’s particularities at the Gli-B1 locus might be conserved since that time and decisively contribute to the current high genetic diversity of common wheat.

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 ◽  
...  
Keyword(s):  
Genetic Basis ◽  
Snp Markers ◽  
Nucleotide Polymorphism ◽  
Rice Varieties ◽  
Single Nucleotide ◽  
Genotyping Platform ◽  
Anaerobic Germination ◽  
Direct Seeded ◽  
Mapping By Sequencing ◽  
Simple Sequence

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.

scholarly journals Candidate Genes for the High-Altitude Adaptations of Two Mountain Pine Taxa

2021 ◽  
Vol 22 (7) ◽  
pp. 3477
Author(s):  
Julia Zaborowska ◽  
Bartosz Łabiszak ◽  
Annika Perry ◽  
Stephen Cavers ◽  
Witold Wachowiak
Keyword(s):  
Population Structure ◽  
Candidate Genes ◽  
Genetic Basis ◽  
Redox Homeostasis ◽  
Snp Markers ◽  
Regulation Of Transcription ◽  
Single Nucleotide ◽  
Homeostasis Regulation ◽  
Genomic Regions ◽  
Mountain Plants

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.

Assessment of diversity in tropical soybean (Glycine max (L.) Merr.) varieties and elite breeding lines using single nucleotide polymorphism markers

2021 ◽  
Vol 19 (1) ◽  
pp. 20-28
Author(s):  
Abush Tesfaye Abebe ◽  
Adesike Oladoyin Kolawole ◽  
Nnanna Unachukwu ◽  
Godfree Chigeza ◽  
Hailu Tefera ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Single Nucleotide Polymorphism ◽  
Glycine Max ◽  
Snp Markers ◽  
Fixation Index ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Breeding Lines ◽  
Soybean Germplasm ◽  
Elite Breeding Lines

AbstractSoybean (Glycine max (L.) Merr.) is an important legume crop with high commercial value widely cultivated globally. Thus, the genetic characterization of the existing soybean germplasm will provide useful information for enhanced conservation, improvement and future utilization. This study aimed to assess the extent of genetic diversity of soybean elite breeding lines and varieties developed by the soybean breeding programme of the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. The genetic diversity of 65 soybean genotypes was studied using single-nucleotide polymorphism (SNP) markers. The result revealed that 2446 alleles were detected, and the indicators for allelic richness and diversity had good differentiating power in assessing the diversity of the genotypes. The three complementary approaches used in the study grouped the germplasm into three major clusters based on genetic relatedness. The analysis of molecular variance revealed that 71% (P < 0.001) variation was due to among individual genotypes, while 11% (P < 0.001) was ascribed to differences among the three clusters, and the fixation index (FST) was 0.11 for the SNP loci, signifying moderate genetic differentiation among the genotypes. The identified private alleles indicate that the soybean germplasm contains diverse variability that is yet to be exploited. The SNP markers revealed high diversity in the studied germplasm and found to be efficient for assessing genetic diversity in the crop. These results provide valuable information that might be utilized for assessing the genetic variability of soybean and other legume crops germplasm by breeding programmes.

scholarly journals A Cotton-Fiber-Associated Cyclin-Dependent Kinase A Gene: Characterization and Chromosomal Location

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Weifan Gao ◽  
Sukumar Saha ◽  
Din-Pow Ma ◽  
Yufang Guo ◽  
Johnie N. Jenkins ◽  
...  
Keyword(s):  
Cotton Fiber ◽  
Sequence Data ◽  
Snp Markers ◽  
Pcr Analysis ◽  
Cyclin Dependent Kinase ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Gene Characterization ◽  
Protein Levels ◽  
Catalytic Domains

A cotton fiber cDNA and its genomic sequences encoding an A-type cyclin-dependent kinase (GhCDKA) were cloned and characterized. The encoded GhCDKA protein contains the conserved cyclin-binding, ATP binding, and catalytic domains. Northern blot and RT-PCR analysis revealed that the GhCDKA transcript was high in 5–10 DPA fibers, moderate in 15 and 20 DPA fibers and roots, and low in flowers and leaves. GhCDKA protein levels in fibers increased from 5–15 DPA, peaked at 15 DPA, and decreased from 15 t0 20 DPA. The differential expression of GhCDKA suggested that the gene might play an important role in fiber development. The GhCDKA sequence data was used to develop single nucleotide polymorphism (SNP) markers specific for the CDKA gene in cotton. A primer specific to one of the SNPs was used to locate the CDKA gene to chromosome 16 by deletion analysis using a series of hypoaneuploid interspecific hybrids.

Single nucleotide polymorphisms of CBF4 locus region of Arabidopsis thaliana correspond to drought tolerance

2004 ◽  
Vol 1 (3) ◽  
pp. 181-190 ◽  
Author(s):  
Hao Gang-Ping ◽  
Wu Zhong-Yi ◽  
Chen Mao-Sheng ◽  
Cao Ming-Qing ◽  
Dominique Brunel ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Drought Tolerance ◽  
World Wide ◽  
Nucleotide Variation ◽  
Nucleotide Polymorphisms ◽  
Water Deficiency ◽  
Coding Region ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Adaptation To Drought

AbstractThe levels of drought tolerance and nucleotide polymorphism at the CBF4 locus were examined in a world-wide sample of 17 core accessions of Arabidopsis thaliana. The results showed that different accessions exhibited considerable differences in adaptation to drought stress. Compared with Columbia accession, the frequency of nucleotide polymorphism at the CBF4 locus of 25av, 203av and 244av accessions, including single nucleotide polymorphism (SNP) and insertion/deletion (Indel), was high, on average 1 SNP per 35.8 bp and 1 Indel per 143 bp. No significance in all regions of Tajima's D test indicated that the neutral mutation hypothesis could explain the nucleotide polymorphism in this CBF4 gene region. The higher polymorphism was the result of purification selection. Nucleotide polymorphism in the non-coding region was three times higher than in the coding region. This might indicate a recent relaxation of selection pressures on the non-coding region of CBF4 gene. In the coding region of CBF4, SNP frequency was 1 SNP per 96.4 bp and one non-synonymous mutation was detected from 25av, 203av and 244av accessions: the amino acid variation gly↔val at position 205, caused by the nucleotide variation G↔T at position 1034 (corresponding to the nucleotide at position 19 696 of GenBank accession no. AB015478 as 1). Furthermore, four differential SNPs were discovered in haplotype 6 constituted by 203av, one of them located in the 3′ non-coding region (A↔C at position 1106) and the others in the 5′ non-coding region (A↔G, A↔C and G↔A at positions 27, 129 and 171, respectively). The drought tolerance assay indicated that accession 203av was the best at tolerating water deficiency. We propose that haplotype 6 is consistent with its drought tolerance.

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