scholarly journals Phenotypic Characterization and Molecular Mapping of Recessive Resistance To Meloidogyne Javanica in Cucumber, Cucumis Sativus

2021 ◽  
Author(s):  
William Brock Rutter ◽  
Abolfazl Hajihassani ◽  
Yuhui Wang ◽  
Yiqun Wang
Keyword(s):  
Candidate Genes ◽  
Cucumis Sativus ◽  
Molecular Mapping ◽  
Meloidogyne Javanica ◽  
Chromosome 1 ◽  
Management Tool ◽  
Phenotypic Characterization ◽  
Resistance Locus ◽  
Root Knot Nematode ◽  
Starting Point

Abstract The Javanese root-knot nematode (JRKN, Meloidogyne javanica) is a serious pest of cucumber (Cucumis sativus) grown in tropical and subtropical regions. The recessive mj resistance gene first identified in the wild cucumber (C. sativus var. hardwickii), is the only known source of resistance to JRKN within the C. sativus gene pool. Despite its potential utility as a nematode management tool, the mj trait has yet to be fully characterized or widely incorporated into commercial cucumber lines. In this study, we mapped the mj resistance locus to a 148-kb interval on cucumber chromosome 1 by phenotyping a recombinant inbred line (RIL) and targeted backcross populations. The genomic interval is predicted to contain 36 candidate genes, including several known to be directly related to plant defense against pathogens. We also conducted histological comparisons of nematode development in mj resistant and susceptible lines, providing evidence that the mechanism of action for this gene may be different from that of known RKN resistance genes. These results provide a set of tightly linked markers that can assist breeding programs seeking to incorporate mj resistance into new cucumber varieties. The candidate genes will also provide a starting point for further research into the mechanisms of action that underlay the mj-regulated JRKN resistance.

scholarly journals Reaction of Avena spp. to different concentration levels of Meloidogyne javanica and M. incognita inoculum

2020 ◽  
pp. 196-203
Author(s):  
Cláudia Fernanda Carraro- Lemes ◽  
Carolina Cardoso Deuner ◽  
Simone Meredith Scheffer- Basso ◽  
Valéria Cecília Ghissi Mazzetti ◽  
Jaqueline Huzar Novakowiski
Keyword(s):  
Meloidogyne Javanica ◽  
Nematode Species ◽  
Management Tool ◽  
Root Knot Nematode ◽  
Inoculum Level ◽  
Breeding Programs ◽  
Resistance Reaction ◽  
Different Response ◽  
Concentration Levels ◽  
Crotalaria Spectabilis

The objective of this study was to evaluate the resistance reaction of Avena spp. after inoculation of different concentrations of eggs and juveniles of M. javanica and M. incognita. Ten oat genotypes (Avena sativa: UPFPS Farroupilha, UPFA Ouro, IPR Afrodite, AF1345 Ucraniana; A. strigosa: Agro Quaraí, Agro Esteio, Embrapa 139, Iapar 61 Ibiporã, UPFA 21 Moreninha, AF 12202) were evaluated in bioassays for resistance against the root-knot nematodes, Meloidogyne javanica and M. incognita. Susceptible (Solanum lycopersicum and Glycine max) and resistant (Crotalaria spectabilis) species were used as control treatments. Depending on the inoculum level, the oats showed a different response to nematodes. All genotypes of oats were resistant to M. javanica when a high inoculum level (5,000 eggs and J2 per plant) was used but under low inoculum level (1,500 eggs and J2 per plant), AF 12202, Iapar 61 Ibiporã, Agro Esteio and Agro Quaraí were susceptible. All genotypes of oats were resistant to the inoculation of 2,900 eggs and J2 of M. incognita, except for ‘Iapar 61’ that showed susceptibility in this concentration. At lower inoculum level (1,500 eggs and J2) Agro Quaraí, Agro Esteio and Iapar 61 Ibiporã were susceptible. The reaction of oats to M. javanica and M. incognita depends on the inoculum level. The resistance reaction at low inoculum density of A. sativa ‘AF 1345 Ucraniana’ and ‘IPR Afrodite’ allows its use in breeding programs in oats and suggests the possibility of management tool in areas infested with both root-knot nematode species.

scholarly journals Genome-Wide Association Study for Resistance to the Meloidogyne javanica Causing Root-Knot Nematode in Soybean

2019 ◽  
Author(s):  
Jean Carlos Alekcevetch ◽  
André Luiz de Lima Passianotto ◽  
Everton Geraldo Capote Ferreira ◽  
Adriana Brombini dos Santos ◽  
Danielle Cristina Gregório da Silva ◽  
...  
Keyword(s):  
Association Study ◽  
Genome Wide Association Study ◽  
In Silico Analysis ◽  
Genotyping By Sequencing ◽  
Meloidogyne Javanica ◽  
Genome Wide Association ◽  
Resistance Locus ◽  
Root Knot Nematode ◽  
Chromosome 13 ◽  
Genome Wide

Meloidogyne javanica causing root-knot nematode in soybean is an important problem in soybean areas, leading to several yield losses. Some accessions have been identified carrying resistance loci to this nematode specie. In this study, a set of 317 soybean accessions were characterized for resistance to M. javanica. Genome-wide association study (GWAS) was performed using SNPs from genotyping-by-sequencing (GBS), and a region of 29.2 Kbp on chromosome 13 was identified. The haplotype analysis showed that SNPs were able to discriminate susceptible and resistant accessions, leading to 25 accessions sharing the resistance locus. Furthermore, 5 accessions may be new M. javanica resistance sources. The screening of the SNPs in the USDA soybean germplasm showed that several accessions previous reported as resistance to other nematodes also showed the resistance haplotype on chromosome 13. High levels of concordance among the phenotypes of Brazilian cultivars and the SNPs in chromosome 13 were observed. A in silico analysis of the mapped region on soybean genome revealed a presence of 5 genes with structural similarity with major resistance genes. The expression levels of the candidate genes in the interval demonstrated a potential pseudogene, and other two model genes up-regulated in the resistance source after pathogen infection. The SNPs associated to the region conferring resistance is a important tool for introgression of the resistance by marker-assisted selection in soybean breeding programs.

scholarly journals Identification of a novel locus, BPH38(t), conferring resistance to brown planthopper (Nilaparvata lugens Stal.) using early backcross population in rice (Oryza sativa L.)

Euphytica ◽  
2019 ◽  
Vol 215 (11) ◽  
Author(s):  
C. H. Balachiranjeevi ◽  
G. D. Prahalada ◽  
A. Mahender ◽  
Md. Jamaloddin ◽  
M. A. L. Sevilla ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
Candidate Genes ◽  
Brown Planthopper ◽  
Snp Markers ◽  
Superior Performance ◽  
Chromosome 1 ◽  
World Population ◽  
Recurrent Parent ◽  
Resistance Locus ◽  
Backcross Population

Abstract Rice is the most important staple food crop, and it feeds more than half of the world population. Brown planthopper (BPH) is a major insect pest of rice that causes 20–80% yield loss through direct and indirect damage. The identification and use of BPH resistance genes can efficiently manage BPH. A molecular marker-based genetic analysis of BPH resistance was carried out using 101 BC1F5 mapping population derived from a cross between a BPH-resistant indica variety Khazar and an elite BPH-susceptible line Huang–Huan–Zhan. The genetic analysis indicated the existence of Mendelian segregation for BPH resistance. A total of 702 high-quality polymorphic single nucleotide polymorphism (SNP) markers, genotypic data, and precisely estimated BPH scores were used for molecular mapping, which resulted in the identification of the BPH38(t) locus on the long arm of chromosome 1 between SNP markers 693,369 and id 10,112,165 of 496.2 kb in size with LOD of 20.53 and phenotypic variation explained of 35.91%. A total of 71 candidate genes were predicted in the detected locus. Among these candidate genes, LOC_Os01g37260 was found to belong to the FBXL class of F-box protein possessing the LRR domain, which is reported to be involved in biotic stress resistance. Furthermore, background analysis and phenotypic selection resulted in the identification of introgression lines (ILs) possessing at least 90% recurrent parent genome recovery and showing superior performance for several agro-morphological traits. The BPH resistance locus and ILs identified in the present study will be useful in marker-assisted BPH resistance breeding programs.

Water supply and sanitation planning model: a management tool for large Brazilian cities

2003 ◽  
Vol 3 (1-2) ◽  
pp. 469-476
Author(s):  
S.R.A. Soares ◽  
R.S. Bernardes
Keyword(s):  
Water Supply ◽  
Low Income ◽  
Management Tool ◽  
Urban Water ◽  
Rapid Urbanization ◽  
Modeling Approach ◽  
Developing Cities ◽  
Starting Point ◽  
Water And Wastewater ◽  
Water Supply And Sanitation

The sanitary problems promoted by the rapid urbanization process in developing cities are usually resulted from the absence of planning, high population concentration and inadequate water and wastewater infrastructure for low income people. Because the provision and planning of water supply and is a complex task, a modeling approach was used to enhance the understanding of the process and the aspects involved. In the development of a model, not only the technical aspects were taken into account, but other aspects related to the provision of drinking water and the water resources protection were also analyzed, such as institutional, financial, socioeconomic, environmental and public health. In the modeling process two different methods of conceptualization were used to describe the urban water flow through the water and wastewater systems linked to various aspects related to their implementation in large developing cities. The urban water systems of five large metropolitan areas in Brazil were also evaluated for the complete model. It is expected that the modeling approach developed in this paper consists of a valuable methodology for water supply and sanitation planning in Brazilian cities, and other developing cities with the same characteristics. The suggested conceptual model could, at least, provide more than a starting point for a useful urban water management tool.

scholarly journals Mineral composition of beetroot treated with potential elicitors and inoculated with Meloidogyne javanica

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Paula Juliana Grotto Débia ◽  
Beatriz Cervejeira Bolanho ◽  
Claudia Regina Dias-Arieira
Keyword(s):  
Population Density ◽  
Mineral Composition ◽  
Integrated Management ◽  
Meloidogyne Javanica ◽  
Nematode Population ◽  
Root Knot Nematode ◽  
Cu Content ◽  
Manganese Zinc ◽  
Nematode Population Density ◽  
Elicitor Treatments

Abstract Background The root-knot nematode Meloidogyne javanica can infect beetroots, causing extensive damage to this food crop. As chemical and genetic control tactics have shown limited efficacy, new strategies are needed to improve the integrated management of this parasite. This study assessed the influence of potential defence elicitors and M. javanica infection on the mineral composition of beetroot. Plants were treated with acibenzolar-S-methyl (ASM), citrus biomass, or a mannanoligosaccharide-based product (MOS) and inoculated with 1000 eggs and second-stage juveniles of M. javanica. At 60 days after inoculation, beetroot plants were harvested and evaluated for nematode population density, vegetative growth, and mineral content. Results All potential elicitors reduced nematode population density in beetroots (p ≤ 0.10) and improved the vegetative parameters of inoculated plants (p ≤ 0.05), except shoot fresh weight. Some minerals were found to be negatively affected by treatments, particularly calcium, whose levels were consistently lower in treated plants. On the other hand, M. javanica inoculation increased magnesium, iron, manganese, zinc, and copper contents in beetroots. However, the latter mineral (Cu content) of inoculated plants was positively influenced by MOS and ASM. Conclusion Potential elicitor treatments did not improve the mineral composition of beetroot, but were effective in reducing nematode population density. Plants inoculated with M. javanica had higher mineral levels. However, gall formation decreases the commercial value of the crop and might render it unsuitable for commercialisation. M. javanica-infected beetroots may be used for nutrient extraction or sold to food processing industries.

scholarly journals High resolution mapping and candidate gene identification of downy mildew race 16 resistance in spinach

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Gehendra Bhattarai ◽  
Wei Yang ◽  
Ainong Shi ◽  
Chunda Feng ◽  
Braham Dhillon ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Downy Mildew ◽  
Association Analysis ◽  
Spinacia Oleracea ◽  
Genotyping By Sequencing ◽  
Significant Snps ◽  
Snp Markers ◽  
Resistance Locus ◽  
Downy Mildew Resistance ◽  
Mildew Resistance

Abstract Background Downy mildew, the most devastating disease of spinach (Spinacia oleracea L.), is caused by the oomycete Peronospora effusa [=P. farinosa f. sp. spinaciae]. The P. effusa shows race specificities to the resistant host and comprises 19 reported races and many novel isolates. Sixteen new P. effusa races were identified during the past three decades, and the new pathogen races are continually overcoming the genetic resistances used in commercial cultivars. A spinach breeding population derived from the cross between cultivars Whale and Lazio was inoculated with P. effusa race 16 in an environment-controlled facility; disease response was recorded and genotyped using genotyping by sequencing (GBS). The main objective of this study was to identify resistance-associated single nucleotide polymorphism (SNP) markers from the cultivar Whale against the P. effusa race 16. Results Association analysis conducted using GBS markers identified six significant SNPs (S3_658,306, S3_692697, S3_1050601, S3_1227787, S3_1227802, S3_1231197). The downy mildew resistance locus from cultivar Whale was mapped to a 0.57 Mb region on chromosome 3, including four disease resistance candidate genes (Spo12736, Spo12784, Spo12908, and Spo12821) within 2.69–11.28 Kb of the peak SNP. Conclusions Genomewide association analysis approach was used to map the P. effusa race 16 resistance loci and identify associated SNP markers and the candidate genes. The results from this study could be valuable in understanding the genetic basis of downy mildew resistance, and the SNP marker will be useful in spinach breeding to select resistant lines.

scholarly journals Identification of Candidate Gene for Internode Length in Rice to Enhance Resistance to Lodging Using QTL Analysis

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1369
Author(s):  
Dan-Dan Zhao ◽  
Ju-Hyeong Son ◽  
Muhammad Farooq ◽  
Kyung-Min Kim
Keyword(s):  
Candidate Genes ◽  
Qtl Analysis ◽  
Middle Part ◽  
Internode Length ◽  
Stem Diameter ◽  
Chromosome 1 ◽  
Doubled Haploid Population ◽  
Lodging Resistance ◽  
Cytochrome P450 Family ◽  
Uppermost Internode

Internode length and stem diameter are the primary traits affecting the lodging resistance of rice. Traits related to the length of the panicle (LP), uppermost internode (LUI), second internode (LSI), third internode (LTI), fourth internode (LFI), lowest internode (LLI) as well as stem diameter at the uppermost internode (SDUI), second internode (SDSI), third internode (SDTI), fourth internode (SDFI), and lowest internode (SDLI) in 120 Cheongcheong/Nagdong doubled haploid population were investigated using a quantitative trait locus (QTL) analysis. Thirty-four QTL regions affected LP and the length of each internode. Twenty-six QTL regions were associated with the stem diameter of each internode. RM12285-RM212 on chromosome 1 contained 10 QTLs related to the internode length, which have overlapped for over 2 years. Twenty-three candidate genes were screened using mark interval. Among the candidate genes, Os01g0803900, named OsCYPq1, which is in the Cytochrome P450 family, might be involved in gibberellins (GA) synthesis. GA is an essential plant growth regulator that affects plant height. OsCYPq1 catalyzes oxidation steps in the middle part of the GA pathway. OsCYPq1 is expected to provide valuable information to improve the marker assessment for target traits and QTL gene cloning in rice.

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