Publications by authors named "Jinguo Hu"

17 Publications

  • Page 1 of 1

Identification of genetic loci associated with forage quality in response to water deficit in autotetraploid alfalfa (Medicago sativa L.).

BMC Plant Biol 2020 Jul 1;20(1):303. Epub 2020 Jul 1.

United States Department of Agriculture-Agricultural Research Service, Plant Germplasm Introduction and Testing Research, 24106 N Bunn Road, Prosser, WA, 99350, USA.

Background: Alfalfa has been cultivated in many regions around the world as an important forage crop due to its nutritive value to livestock and ability to adapt to various environments. However, the genetic basis by which plasticity of quality-relevant traits influence alfalfa adaption to different water conditions remain largely unknown.

Results: In the present study, 198 accessions of alfalfa of the core collection for drought tolerance were evaluated for 26 forage quality traits in a field trial under an imposed deficit irrigation gradient. Regression analysis between quality traits and water stress revealed that values of fiber-related traits were negatively correlated with values of energy-related traits as water deficit increased. More than one hundred significant markers associated with forage quality under different water treatments were identified using genome-wide association studies with genotyping by sequencing. Among them, 131 markers associated with multiple traits in all the water deficit treatments. Most of the associated markers were dependent to the levels of water deficit, suggesting genetic controls for forage quality traits were dependent to the stress treatment. Twenty-four loci associated with forage quality were annotated to functional genes that may play roles in cell development or in response to water stress.

Conclusions: This study addressed the genetic base of phenotypic variation of forage quality traits under water deficit. The SNP markers identified in this study will be useful in marker-assisted selection for the genetic improvement of alfalfa with enhanced drought tolerance while maintaining forage quality.
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http://dx.doi.org/10.1186/s12870-020-02520-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7328273PMC
July 2020

Genetic diversity analysis for narrow-leafed lupin (Lupinus angustifolius L.) by SSR markers.

Mol Biol Rep 2020 Jul 23;47(7):5215-5224. Epub 2020 Jun 23.

The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.

Narrow-leafed lupin (Lupinus angustifolius L.) is used as grain legumes, fodder for livestock and green manure in the world and has a great potential to be developed as a new crop in China. In this study, we assessed the genetic diversity among a set of 109 newly introduced accessions of narrow-leafed lupin using 76 genomic SSR markers. Data analysis suggested that the average gene diversity index and average polymorphism information content (PIC) were 0.4758 and 0.4328, respectively. The mean allele number per loci (Na) was 6.3816. The population structure analysis identified two subgroups based on delta K (ΔK) values. This result is in accordance with that of a PCA. The AMOVA analysis showed that most of molecular variance were within population. These results will be useful to guide the genetic improvement of the narrow-leafed lupin crop in China.
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http://dx.doi.org/10.1007/s11033-020-05596-zDOI Listing
July 2020

Construction of High-Density Linkage Maps and Identification of Quantitative Trait Loci Associated with Verticillium Wilt Resistance in Autotetraploid Alfalfa ( L.).

Plant Dis 2020 May 9;104(5):1439-1444. Epub 2020 Mar 9.

United States Department of Agriculture-Agricultural Research Service, Plant Germplasm Introduction and Testing Research, 24106 N Bunn Road, Prosser, WA, U.S.A.

Verticillium wilt (VW) of alfalfa is a devastating disease that causes forage yield reductions of up to 50% in the northern United States and Canada. The most effective method for controlling the disease is through the development and use of resistant varieties. To identify quantitative trait loci (QTL) for VW resistance in alfalfa, we used a full-sib population segregating for VW resistance. High-density linkage maps for both resistant and susceptible parents were constructed using single-dose alleles of single-nucleotide polymorphism markers generated by genotyping-by-sequencing. Five QTL associated with VW resistance were identified and they were in four linkage groups (4D, 6B, 6D, and 8C). Of those, three QTL (, and ) had higher logarithm of odds. Two putative candidates of nucleotide-binding site leucine-rich repeat disease resistance genes were identified in the QTL intervals of and , respectively. The result agreed with our previous studies, in which similar resistance loci were identified in an association panel using genome-wide association. The results provide insight into the quantitative resistance to VW in alfalfa. The resistance loci and closely linked markers identified in the present study can be used in developing new alfalfa varieties with enhanced resistance to VW.
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http://dx.doi.org/10.1094/PDIS-08-19-1718-REDOI Listing
May 2020

Distinct Metabolome Changes during Seed Germination of Lettuce ( L.) in Response to Thermal Stress as Revealed by Untargeted Metabolomics Analysis.

Int J Mol Sci 2020 Feb 21;21(4). Epub 2020 Feb 21.

Shanghai Agrobiological Gene Center, Shanghai 201106, China.

Temperature strongly influences lettuce ( L.) seed germination. Different lettuce genotypes respond differently to higher temperatures or thermal stress. In this study, we evaluated the germination performance of 304 lettuce accessions incubated at three temperature settings, 21 °C, 28 °C and 35 °C, respectively, for 40 h. At 21 °C, seeds of all 304 accessions germinated with very well an average germination percentage of 87.72%; at 28 °C, the average germination percentage dropped to 42.84% and at 35 °C, the germination decreased to 1.01%. Then, we investigated changes in metabolic profiles of lettuce seed response to thermal stress using an untargeted metabolomics approach. Results suggested that seeds of thermal-sensitive and thermal-tolerant cultivars employed different metabolic strategies in response to thermal stress during germination. Thermal-sensitive buds accumulated more significant amounts of organic acids, amino acids, sugars, sterols, phenolic compounds and terpenoids compared to thermal-tolerant buds at 21 °C. Thermal-tolerant lettuce cultivar accumulated higher concentrations of amino acids, organic acids, sugars, sesquiterpene lactones, sterols, and fatty acids derivatives during the germination at 35 °C compared to germinated at 21 °C. This investigation paves the way to link the metabolomics to other external and internal factors affecting lettuce seed germination under thermal stress.
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http://dx.doi.org/10.3390/ijms21041481DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7073097PMC
February 2020

Effect of Thermal Extraction on Coal-Based Activated Carbon for Methane Decomposition to Hydrogen.

ACS Omega 2020 Feb 29;5(5):2465-2472. Epub 2020 Jan 29.

Coal Engineering College, Shanxi Datong University, Datong 037003, Shanxi, China.

After coal is treated by thermal solution of solvent, a certain amount of thermal solution oil and residue can be obtained, and the macromolecular network structure in coal can also be relaxed. These will inevitably affect the emission of harmful gases and distribution of the pore structure when the residue is made into activated carbon (AC). In this paper, the effects of thermal solution pretreatment on the microcrystalline structure, surface properties, pore structure of resultant ACs at different temperatures, and their catalytic performances in methane decomposition to hydrogen were investigated. The results show that the surface oxygen-containing functional groups of the residue-based ACs are changed, and the specific area of ACs increases from 1730 to 2652 m/g with the increase in activated temperature. The pore diameter distribution of ACs also is changed. In the process of methane decomposition to hydrogen, the residue-based ACs show higher catalytic activity than coal-based ACs. AC-1123-1 and AC-1123 show the best stability, while AC-823-1 has the highest initial activity. With the increase in activated temperature, residue-based ACs show higher activity and stability, and partial fibrous carbon is deposited on the surface of ACs after the reaction. It is thought that increased mesoporosity is beneficial to the catalytic activity and stability of AC in methane decomposition to hydrogen, and the reduction of surface oxygen-containing functional groups contribute to the formation of fibrous carbon on the surface of AC after the reaction.
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http://dx.doi.org/10.1021/acsomega.9b04044DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7017400PMC
February 2020

An RNA Sequencing Transcriptome Analysis of Grasspea ( L.) and Development of SSR and KASP Markers.

Front Plant Sci 2017 31;8:1873. Epub 2017 Oct 31.

National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.

Grasspea ( L., 2n = 14) has great agronomic potential because of its ability to survive under extreme conditions, such as drought and flood. However, this legume is less investigated because of its sparse genomic resources and very slow breeding process. In this study, 570 million quality-filtered and trimmed cDNA sequence reads with total length of over 82 billion bp were obtained using the Illumina NextSeq 500 platform. Approximately two million contigs and 142,053 transcripts were assembled from our RNA-Seq data, which resulted in 27,431 unigenes with an average length of 1,250 bp and maximum length of 48,515 bp. The unigenes were of high-quality. For example, the stay-green (SGR) gene of grasspea was aligned with the SGR gene of pea with high similarity. Among these unigenes, 3,204 EST-SSR primers were designed, 284 of which were randomly chosen for validation. Of these validated unigenes, 87 (30.6%) EST-SSR primers produced polymorphic amplicons among 43 grasspea accessions selected from different geographical locations. Meanwhile, 146,406 SNPs were screened and 50 SNP loci were randomly chosen for the kompetitive allele-specific PCR (KASP) validation. Over 80% (42) SNP loci were successfully transformed to KASP markers. Comparison of the dendrograms according to the SSR and KASP markers showed that the different marker systems are partially consistent with the dendrogram constructed in our study.
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http://dx.doi.org/10.3389/fpls.2017.01873DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5671653PMC
October 2017

Marker-trait association analysis of frost tolerance of 672 worldwide pea (Pisum sativum L.) collections.

Sci Rep 2017 07 19;7(1):5919. Epub 2017 Jul 19.

Center for Crop Germplasm Resources/Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.

Frost stress is one of the major abiotic stresses causing seedling death and yield reduction in winter pea. To improve the frost tolerance of pea, field evaluation of frost tolerance was conducted on 672 diverse pea accessions at three locations in Northern China in three growing seasons from 2013 to 2016 and marker-trait association analysis of frost tolerance were performed with 267 informative SSR markers in this study. Sixteen accessions were identified as the most winter-hardy for their ability to survive in all nine field experiments with a mean survival rate of 0.57, ranging from 0.41 to 0.75. Population structure analysis revealed a structured population of two sub-populations plus some admixtures in the 672 accessions. Association analysis detected seven markers that repeatedly had associations with frost tolerance in at least two different environments with two different statistical models. One of the markers is the functional marker EST1109 on LG VI which was predicted to co-localize with a gene involved in the metabolism of glycoproteins in response to chilling stress and may provide a novel mechanism of frost tolerance in pea. These winter-hardy germplasms and frost tolerance associated markers will play a vital role in marker-assisted breeding for winter-hardy pea cultivar.
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http://dx.doi.org/10.1038/s41598-017-06222-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5517424PMC
July 2017

Molecular Mapping of High Resistance to Bacterial Leaf Spot in Lettuce PI 358001-1.

Phytopathology 2016 11 27;106(11):1319-1325. Epub 2016 Jul 27.

First and second authors: Everglades Research and Education Center, University of Florida/Institute of Food and Agricultural Sciences, Belle Glade 33430; and third author: United States Department of Agriculture-Agricultural Research Service, Western Regional Plant Introduction Station, Washington State University, Pullman 99164.

Lettuce (Lactuca sativa L.) is a diploid (2n = 18) with a genome size of 2,600 Mbp, and belongs to the family Compositae. Bacterial leaf spot (BLS), caused by Xanthomonas campestris pv. vitians, is a major disease of lettuce worldwide. Leaf lettuce PI 358001-1 has been characterized as an accession highly resistant to BLS and has white seed. In order to understand inheritance of the high resistance in this germplasm line, an F population consisting of 163 families was developed from the cross PI 358001-1 × 'Tall Guzmaine' (a susceptible Romaine lettuce variety with black seed). The segregation ratio of reaction to disease by seedling inoculation with X. campestris pv. vitians L7 strain in the F families was shown to be 32:82:48 homozygous resistant/heterozygous/homozygous susceptible, fitting to 1:2:1 (n = 162, χ = 3.19, P = 0.20). The segregation ratio of seed color by checking F plants was 122:41 black/white, fitting to 3:1 (n = 163, χ = 0.002, P = 0.96). The results indicated that both BLS resistance and seed color were inherited as a dominant gene mode. A genetic linkage map based on 124 randomly selected F plants was developed to enable molecular mapping of the BLS resistance and the seed color trait. In total, 199 markers, comprising 176 amplified fragment length polymorphisms, 16 simple-sequence repeats, 5 resistant gene candidate markers, and 2 cleaved amplified polymorphic sequences (CAPS) markers were assigned to six linkage groups. The dominant resistance gene to BLS (Xcvr) was mapped on linkage group 2 and the gene locus y for seed color was identified on linkage group 5. Due to the nature of a single gene inheritance, the high-resistance gene should be readily transferred to adapted lettuce cultivars to battle against the devastating disease of lettuce.
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http://dx.doi.org/10.1094/PHYTO-09-15-0238-RDOI Listing
November 2016

High-Throughput Development of SSR Markers from Pea (Pisum sativum L.) Based on Next Generation Sequencing of a Purified Chinese Commercial Variety.

PLoS One 2015 6;10(10):e0139775. Epub 2015 Oct 6.

The National Key Facility for Crop Gene Resources and Genetic Improvement/Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.

Pea (Pisum sativum L.) is an important food legume globally, and is the plant species that J.G. Mendel used to lay the foundation of modern genetics. However, genomics resources of pea are limited comparing to other crop species. Application of marker assisted selection (MAS) in pea breeding has lagged behind many other crops. Development of a large number of novel and reliable SSR (simple sequence repeat) or microsatellite markers will help both basic and applied genomics research of this crop. The Illumina HiSeq 2500 System was used to uncover 8,899 putative SSR containing sequences, and 3,275 non-redundant primers were designed to amplify these SSRs. Among the 1,644 SSRs that were randomly selected for primer validation, 841 yielded reliable amplifications of detectable polymorphisms among 24 genotypes of cultivated pea (Pisum sativum L.) and wild relatives (P. fulvum Sm.) originated from diverse geographical locations. The dataset indicated that the allele number per locus ranged from 2 to 10, and that the polymorphism information content (PIC) ranged from 0.08 to 0.82 with an average of 0.38. These 1,644 novel SSR markers were also tested for polymorphism between genotypes G0003973 and G0005527. Finally, 33 polymorphic SSR markers were anchored on the genetic linkage map of G0003973 × G0005527 F2 population.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0139775PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4595016PMC
June 2016

Large-scale microsatellite development in grasspea (Lathyrus sativus L.), an orphan legume of the arid areas.

BMC Plant Biol 2014 Mar 17;14:65. Epub 2014 Mar 17.

The National Key Facility for Crop Gene Resources and Genetic Improvement/Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.

Background: Grasspea (Lathyrus sativus L., 2n = 14), a member of the family Leguminosae, holds great agronomic potential as grain and forage legume crop in the arid areas for its superb resilience to abiotic stresses such as drought, flood and salinity. The crop could not make much progress through conventional breeding in the past, and there are hardly any detailed molecular biology studies due to paucity of reliable molecular markers representative of the entire genome.

Results: Using the 454 FLX Titanium pyrosequencing technique, 651,827 simple sequence repeat (SSR) loci were identified and 50,144 nonredundant primer pairs were successfully designed, of which 288 were randomly selected for validation among 23 L. sativus and one L. cicera accessions of diverse provenance. 74 were polymorphic, 70 monomorphic, and 144 with no PCR product. The number of observed alleles ranged from two to five, the observed heterozygosity from 0 to 0.9545, and Shannon's information index ranged from 0.1013 to 1.0980, respectively. The dendrogram constructed by using unweighted pair group method with arithmetic mean (UPGMA) based on Nei's genetic distance, showed obvious distinctions and understandable relationships among the 24 accessions.

Conclusions: The large number of SSR primer pairs developed in this study would make a significant contribution to genomics enabled improvement of grasspea.
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http://dx.doi.org/10.1186/1471-2229-14-65DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4003855PMC
March 2014

Detrimental and neutral effects of a wild grass-fungal endophyte symbiotum on insect preference and performance.

J Insect Sci 2011 ;11:77

USDA, ARS Plant Germplasm Introduction and Testing Research Unit, 59 Johnson Hall, Washington State University, Pullman, WA 99164-6402, USA.

Seed-borne Epichloë/Neotyphodium Glenn, Bacon, Hanlin (Ascomycota: Hypocreales: Clavicipitaceae) fungal endophytes in temperate grasses can provide protection against insect attack with the degree of host resistance related to the grass-endophyte symbiotum and the insect species involved in an interaction. Few experimental studies with wild grass-endophyte symbiota, compared to endophyte-infected agricultural grasses, have tested for anti-insect benefits, let alone for resistance against more than one insect species. This study quantified the preference and performance of the bird cherry oat-aphid, Rhopalosiphum padi (L.) (Hemiptera: Aphididae) and the cereal leaf beetle, Oulema melanopus (L.) (Coleoptera: Chrysomelidae), two important pests of forage and cereal grasses, on Neotyphodium-infected (E+) and uninfected (E-) plants of the wild grass Alpine timothy, Phleum alpinum L. (Poales: Poaceae). The experiments tested for both constitutive and wound-induced resistance in E+ plants to characterize possible plasticity of defense responses by a wild E+ grass. The aphid, R. padi preferred E- over E+ test plants in choice experiments and E+ undamaged test plants constitutively expressed antibiosis resistance to this aphid by suppressing population growth. Prior damage of E+ test plants did not induce higher levels of resistance to R. padi. By contrast, the beetle, O. melanopus showed no preference for E+ or E- test plants and endophyte infection did not adversely affect the survival and development of larvae. These results extend the phenomenon of variable effects of E+ wild grasses on the preference and performance of phytophagous insects. The wild grass- Neotyphodium symbiotum in this study broadens the number of wild E+ grasses available for expanded explorations into the effects of endophyte metabolites on insect herbivory.
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http://dx.doi.org/10.1673/031.011.7701DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3281469PMC
November 2011

Genetic characterization and molecular mapping of a chlorophyll deficiency gene in sunflower (Helianthus annuus).

J Plant Physiol 2009 Apr 22;166(6):644-51. Epub 2008 Oct 22.

Department of Plant Sciences, North Dakota State University, Fargo, ND 58105, USA.

A major gene controlling chlorophyll deficiency (phenotyped by yellow leaf color, yl) in sunflower was identified and mapped in an F(2) population derived from a cross between two breeding lines. Greenness degree was scored by a hand-held chlorophyll meter in the F(2) population. Leaf tissue from the parents, F(1) hybrids, and some F(2) progenies were also sampled to determine the chlorophyll content. All F(1) plants had normal green leaf color and the segregation of the plants in the F(2) population fits the monogenic ratio (chi((3:1))(2)=0.03, p>0.9), indicating that leaf color is a monogenic trait with normal green dominant over yellow leaf color in this population. The contents of chlorophyll a, chlorophyll b, and total chlorophyll in the yellow-leafed lines were reduced by 41.6%, 53.5%, and 44.3%, respectively, in comparison with those in the green-leafed lines. Genetic mapping with molecular markers positioned the gene, yl, to linkage group 10 of sunflower. An SSR marker, ORS 595, cosegregated with yl, and a TRAP marker, B26P17ga5-300, was linked to yl with a genetic distance of 4.2cM. The molecular marker tightly linked to the chlorophyll deficiency gene will provide insight into the process of chlorophyll metabolism in sunflower.
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http://dx.doi.org/10.1016/j.jplph.2008.09.008DOI Listing
April 2009

Mapping one of the 2 genes controlling lemon ray flower color in sunflower (Helianthus annuus L.).

J Hered 2008 Sep-Oct;99(5):564-7. Epub 2008 May 13.

Department of Plant Sciences, North Dakota State University, Fargo, ND 58105, USA.

In an F2 population of 120 plants derived from a cross between 2 breeding lines with yellow ray flowers, we observed 111 plants with yellow-colored and 9 plants with lemon-colored ray flowers. The segregation pattern fits a 15:1 (chi2(15:1) = 0.32, P > 0.5) ratio, suggesting that the lemon ray flower color is conditioned by 2 independent recessive genes that had been contributed individually by each of the parents. We sampled 111 plants from the 3 F(2:3) families displaying a 3 to 1 segregating ratio for genotyping with molecular markers. One of the genes, Yf(1), was mapped onto linkage group 11 of the public sunflower map. A targeted region amplified polymorphism marker (B26P17Trap13-68) had a genetic distance of 1.5 cM to Yf(1), and one simple sequence repeat marker (ORS733) and one expressed sequence tag (EST)-based marker (HT167) previously mapped to linkage group 11 were linked to Yf(1) with distances of 9.9 and 2.3 cM, respectively.
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http://dx.doi.org/10.1093/jhered/esn033DOI Listing
September 2008

Molecular mapping of an apical branching gene of cultivated sunflower (Helianthus annuus L.).

Theor Appl Genet 2008 Jun 4;117(1):19-28. Epub 2008 Apr 4.

Department of Plant Sciences, North Dakota State University, Fargo, ND 58105, USA.

Commercial hybrids of cultivated sunflower (Helianthus annuus L.) are obtained by crossing a cytoplasmic male sterile line (A-line) with a restorer pollinator (R-line). The incorporation of a recessive branching trait to extend the pollination period of R-lines during hybrid seed production is laborious and time-consuming. By using target region polymorphism (TRAP) and bulked segregant analysis (BSA), we identified 15 TRAP markers linked to the b(1) (branching) locus in a population of 229 F(2) plants derived from a cross between nonbranched (HA 234) and branched (RHA 271) lines. TBr4-720 and TBr8-555 markers were linked to the b(1) gene in the coupling phase at 0.5 cM (0.004 recombination frequency). The Tbr20-297 and Tbr20-494 markers flanked the b(1) locus in the repulsion phase at genetic distances of 7.5 and 2.5 cM, respectively. Tbr19-395, also in the repulsion phase, mapped at 3.8 cM from the b(1) locus and on the opposite side of the marker Tbr20-297. The 8A1 and 15B3 restriction fragment length polymorphic (RFLP) markers of linkage group (LG) 16 of the RHA 271 x HA 234 cultivated sunflower map anchored the b(1) LG onto the RFLP map. Polymerase chain reaction (PCR)-based markers tightly linked to the recessive b(1) gene have been developed. Their identification and the incorporation of the LG containing the b(1) locus onto an RFLP map will be useful for marker-assisted selection (MAS) in breeding programs and provide the bases for map-based cloning of this gene.
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http://dx.doi.org/10.1007/s00122-008-0748-9DOI Listing
June 2008

Defining the sunflower (Helianthus annuus L.) linkage group ends with the Arabidopsis-type telomere sequence repeat-derived markers.

Authors:
Jinguo Hu

Chromosome Res 2006 12;14(5):535-48. Epub 2006 Jul 12.

U.S. Department of Agriculture, Agricultural Research Service, Northern Crop Science Laboratory, Fargo, ND 58105, USA.

The target region amplification polymorphism (TRAP) marker technique was employed to define sunflower (Helianthus annuus L.) linkage group ends. In combination with eight arbitrary primers, nine fixed primers containing the Arabidopsis-type telomere repeat sequences worked successfully in generating polymorphic markers in the mapping population of 92 F(7) recombinant inbred lines (RIL) derived from the cross RHA 280 x RHA 801. This population was used in the construction of the densest sunflower linkage map of 577 simple sequence repeat (SSR) markers. With 18 sets of PCR reactions, 226 polymorphic TRAP markers were amplified from the two parental lines and 92 RIL. The computer program, Mapmaker, placed 183 markers into the established 17 linkage groups of the SSR map. Although most of the added markers spread across the genome, 32 markers were mapped to the outermost positions of the linkage groups, defining 21 of the 34 linkage group ends of the sunflower linkage map. The telomeric origin of a few of these markers was confirmed by sequence analyses. These telomere-associated markers will provide an accurate assessment of the completeness of a linkage group and a better estimate of the actual genetic lengths. The potential application of the telomere mapping to sunflower improvement is discussed.
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http://dx.doi.org/10.1007/s10577-006-1051-8DOI Listing
October 2006

Genetic characterization and molecular mapping of Hessian fly resistance genes derived from Aegilops tauschii in synthetic wheat.

Theor Appl Genet 2006 Aug 15;113(4):611-8. Epub 2006 Jun 15.

Department of Plant Science, North Dakota State University, Fargo, ND 58105, USA.

Two synthetic hexaploid wheat lines (xAegilotriticum spp., 2n = 6x = 42, genomes AABBDD), SW8 and SW34, developed from the crosses of the durum wheat cultivar Langdon (Triticum turgidum L. var. durum, 2n = 4x = 28, genomes AABB) with two Aegilops tauschii Cosson accessions (2n = 2x = 14, genome DD), were determined to carry Hessian fly [Mayetiola destructor (Say)] resistance genes derived from the Ae. tauschii parents. SW8 was resistant to the Hessian fly biotype Great Plains (GP) and strain vH13 (virulent to H13). SW34 was resistant to biotype GP, but susceptible to strain vH13. Allelism tests indicated that resistance genes in SW8 and SW34 may be allelic to H26 and H13 or correspond to paralogs at both loci, respectively. H26 and H13 were localized to chromosome 4D and 6D, respectively, in previous studies. Molecular mapping in the present study, however, assigned the H26 locus to chromosome 3D rather than 4D. On the other hand, mapping of the resistance gene in SW34 verified the previous assignment of the H13 locus to chromosome 6D. Linkage analysis and physical mapping positioned the H26 locus to the chromosomal deletion bin 3DL3-0.81-1.00. A linkage map for each of these two resistance genes was constructed using simple sequence repeat (SSR) and target region amplification polymorphism (TRAP) markers.
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http://dx.doi.org/10.1007/s00122-006-0325-zDOI Listing
August 2006

Molecular mapping of a nuclear male-sterility gene in sunflower (Helianthus annuus L.) using TRAP and SSR markers.

Theor Appl Genet 2006 Jun 14;113(1):122-7. Epub 2006 Apr 14.

Department of Plant Sciences, North Dakota State University, Fargo, ND 58105, USA.

A nuclear male-sterile mutant, NMS 360, induced by streptomycin from an inbred maintainer line HA 89, possesses a single recessive gene, ms9, controlling male sterility. The present study identified DNA markers linked to the ms9 gene in an F2 population derived from the cross of NMS 360 x RHA 271 and maps the ms9 gene to an existing sunflower SSR linkage map. Bulked segregant analysis was performed using the target region amplification polymorphism (TRAP) marker technique and the simple sequence repeats (SSR) technique. From 444 primer combinations, six TRAP markers linked with the ms9 gene were amplified. Two markers, Ts4p03-202 and Tt3p09-529, cosegregated with the ms9 gene. The other four markers, To3d14-310, Tt3p17-390, Ts4p23-300, and Tt3p09-531, linked with ms9 at a distance of 1.2, 3.7, 10.3, and 22.3 cM, respectively. Thirty SSR primers from 17 linkage groups of a PHA x PHB cultivated sunflower linkage map were screened among the two parents and the F2 population. SSR primer ORS 705 of linkage group 10 was tightly linked to ms9 at a distance of 1.2 cM. The ms9 gene was subsequently mapped to linkage group 10 of the public sunflower SSR linkage map. The markers that were tightly linked with the ms9 gene will be useful in marker-assisted selection of male-sterile plants among segregating populations, and will facilitate the isolation of the ms9 gene by map-based cloning.
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http://dx.doi.org/10.1007/s00122-006-0278-2DOI Listing
June 2006
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