Fine-mapping the recently discovered QTL qMrdd2 that confers resistance to maize rough dwarf disease

Abstract Background: Maize rough dwarf disease (MRDD) is a disease caused by a virus that seriously affects maize yield and quality worldwide. Rice black streaked dwarf virus (RBSDV) in the Fijivirus genus in the Reoviridae family causes MRDD in maize. Typical MRDD symptoms of include severe dwarfing of plants, shortening of internodes. MRDD resistance is a complex trait that is quantitatively inherited and is controlled by several quantitative trait loci (QTL). MRDD is most efficiently controlled by the cultivation of disease-resistant corn hybrids. Results: Disease resistance in the MRDD-resistant Qi319 and -susceptible Ye478 parental inbred lines and the 314 recombinant inbred lines (RILs) that were derived from a cross between them was evaluated across three environments. A stable resistance QTL, qMrdd2 , which explained 8.64 to 11.02% of the total phenotypic variance in MRDD resistance, was identified repeatedly and was mapped using BLUP values to a 0.55-Mb region between the markers MK807 and MK811 on chromosome 2. We validated the effect of qMrdd2 using a chromosome segment substitution line population that were derived from a cross between maize inbred Qi319 as the resistance donor and Ye478 as the recipient. The disease-severity index (DSI) of CSSL haplotype II harboring qMrdd2 was significantly lower than the DSI of susceptible parent Ye478 ( P < 0.05). Mapping results using CSSLs were consistent with localization interval determined using RILs. The qMrdd2 locus acted with an additive effect but no significant dominant gene action in conferring MRDD resistance. We fine-mapped qMrdd2 locus into a 315-kb region flanked by the markers RD81 and RD87 by testing recombinant-derived progeny using selfed backcrossed families. Conclusions: qMrdd2 is a recently discovered QTL from Qi319 for resistance to MRDD with an additive effect but no significant dominant gene action for MRDD resistance. qMrdd2 was fine-mapped to a 315-kb interval on maize chromosome 2. Introgression of the MRDD resistance allele at the qMrdd2 locus of CSSL haplotype 2 using linked markers umc1824 and bnlg125 will be useful for maize breeding to reduce yield losses caused by MRDD. Keywords: Maize, Maize rough dwarf disease, QTL, Fine-mapping, RIL；CSSL.

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Identification and Fine-Mapping of a Novel QTL qMrdd2 Conferring Resistance to Maize Rough Dwarf Disease

Plant Disease ◽

10.1094/pdis-03-20-0495-re ◽

2021 ◽

Author(s):

Zhennan Xu ◽

Feifei Wang ◽

Zhiqiang Zhou ◽

Qingchang Meng ◽

Yanping Chen ◽

...

Keyword(s):

Fine Mapping ◽

Recombinant Inbred ◽

Recombinant Inbred Lines ◽

Substitution Line ◽

Chromosome Segment ◽

Phenotypic Variance ◽

Chromosome Segment Substitution Line ◽

Maize Rough Dwarf Disease ◽

Dwarf Disease ◽

Segment Substitution

Maize rough dwarf disease (MRDD), caused by a virus, seriously affects maize quality and yield worldwide. MRDD can be most effectively controlled with disease-resistant hybrids of corn. Here, MRDD-resistant (Qi319) and -susceptible (Ye478) parental inbred maize lines and their 314 recombinant inbred lines (RILs) that were derived from a cross between them were evaluated across three environments. A stable resistance QTL, qMrdd2, was identified and mapped using BLUP values to a 0.55 Mb region between the markers MK807 and MK811 on chromosome 2 (B73 RefGen_v3), which was found to explain 8.6 to 11.0% of the total phenotypic variance in MRDD resistance. We validated the effect of qMrdd2 using a chromosome segment substitution line (CSSL) that was derived from a cross between maize inbred Qi319 as the MRDD resistance donor and Ye478 as the recipient. Disease severity index of the CSSL haplotype II harboring qMrdd2 was significantly lower than that of the susceptible parent Ye478. Subsequently, we fine-mapped qMrdd2 to a 315 kb region flanked by the markers RD81 and RD87 by testing recombinant-derived progeny using selfed backcrossed families. In this study, we identified a novel QTL for MRDD-resistance by combining the RIL and CSSL populations, which can be used to breed for MRDD resistant varieties of maize. Keywords: Maize, Maize rough dwarf disease, QTL, Fine-mapping, Recombinant inbred line, Chromosome segment substitution line.

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Identification and fine-mapping of a QTL, qMrdd1, that confers recessive resistance to maize rough dwarf disease

BMC Plant Biology ◽

10.1186/1471-2229-13-145 ◽

2013 ◽

Vol 13 (1) ◽

pp. 145 ◽

Cited By ~ 27

Author(s):

Yongfu Tao ◽

Qingcai Liu ◽

Honghong Wang ◽

Yanjun Zhang ◽

Xinyi Huang ◽

...

Keyword(s):

Fine Mapping ◽

Recessive Resistance ◽

Maize Rough Dwarf Disease ◽

Dwarf Disease

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Fine Mapping of a New Race-Specific Blast Resistance Gene, Pi-hk2, in Japonica Heikezijing from Taihu Region of China

Phytopathology ◽

10.1094/phyto-03-16-0151-r ◽

2017 ◽

Vol 107 (1) ◽

pp. 84-91 ◽

Cited By ~ 2

Author(s):

Wanwan He ◽

Nengyan Fang ◽

Ruisen Wang ◽

Yunyu Wu ◽

Guoying Zeng ◽

...

Keyword(s):

Resistance Gene ◽

Fine Mapping ◽

Broad Spectrum ◽

Blast Resistance ◽

Recombinant Inbred Lines ◽

Japonica Rice ◽

Phenotypic Variance ◽

Chromosome 11 ◽

Essential Information ◽

Broad Spectrum Resistance

Heikezijing, a japonica rice landrace from the Taihu region of China, exhibited broad-spectrum resistance to more than 300 isolates of the blast pathogen (Magnaporthe oryzae). In our previous research, we fine mapped a broad-spectrum resistance gene, Pi-hk1, in chromosome 11. In this research, 2010-9(G1), one of the predominant races of blast in the Taihu Lake region of China, was inoculated into 162 recombinant inbred lines (RIL) and two parents, Heikezijing and Suyunuo, for mapping the resistance-blast quantitative trait loci (QTL). Three QTL (Lsqtl4-1, Lsqtl9-1, and Lsqtl11-1) associated with lesion scores were detected on chromosomes 4, 9, and 11 and two QTL (Lnqtl1-1 and Lnqtl9-1) associated with average lesion numbers were detected on chromosomes 1 and 9. The QTL Lsqtl9-1 conferring race-specific resistance to 2010-9(G1) at seedling stages showed logarithm of the odds scores of 9.10 and phenotypic variance of 46.19% and might be a major QTL, named Pi-hk2. The line RIL84 with Pi-hk2 derived from a cross between Heikezijing and Suyunuo was selected as Pi-hk2 gene donor for developing fine mapping populations. According to the resistance evaluation of recombinants of three generations (BC1F2, BC1F3, and BC1F4), Pi-hk2 was finally mapped to a 143-kb region between ILP-19 and RM24048, and 18 candidate genes were predicted, including genes that encode pleiotropic drug resistance protein 4 (n = 2), WRKY74 (n = 1), cytochrome b5-like heme/steroid-binding domain containing protein (n = 1), protein kinase (n = 1), and ankyrin repeat family protein (n = 1). These results provide essential information for cloning of Pi-hk2 and its potential utility in breeding resistant rice cultivars by marker-assisted selection.

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Fine mapping of consistent quantitative trait loci for yield under drought stress using rice (Oryza sativa) recombinant inbred lines adapted to rainfed environment

Current Science ◽

10.18520/v109/i5/910-917 ◽

2015 ◽

Vol 109 (5) ◽

pp. 910

Author(s):

C. Muthukumar ◽

V. Deshmukh Vivek ◽

R. Poornima ◽

S. Kavitha ◽

V. Gayathri ◽

...

Keyword(s):

Oryza Sativa ◽

Drought Stress ◽

Quantitative Trait Loci ◽

Fine Mapping ◽

Quantitative Trait ◽

Recombinant Inbred ◽

Recombinant Inbred Lines ◽

Inbred Lines ◽

Trait Loci

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A new allele of the testosterone-responsive gene, Hdc-a, in the histidine decarboxylase gene complex of the mouse

Genetics Research ◽

10.1017/s0016672300023727 ◽

1987 ◽

Vol 50 (3) ◽

pp. 213-217

Author(s):

Richard J. Middleton ◽

Kathleen Williamson ◽

Grahame Bulfield

Keyword(s):

Recombinant Inbred ◽

Histidine Decarboxylase ◽

Recombinant Inbred Lines ◽

Regulatory Gene ◽

Inbred Lines ◽

Chromosome 2 ◽

Gene Complex ◽

Responsive Gene

SummaryIn C57BL/10 and the majority of other strains of mice, females have about 20-fold higher kidney histidine decarboxylase levels than males; in DBA/2 mice, however, HDC in females is only 3- to 4-fold higher than males. The low ratio HDC phenotype of DBA/2 animals is due to decreased sensitivity of the HDC gene complex to repression by testosterone in males. From conventional crosses and by the use of the BXD recombinant inbred lines we conclude that the C57BL/ 10: DBA/2 difference, in testosterone sensitivity of HDC, is due to an allelic difference in the regulatory gene Hdc-a of the HDC gene complex, [Hdc], on chromosome 2; DBA/2 contains a third allele of this gene, Hdc-ad.

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Genetic Mapping of the Scab Resistance Gene in Cucumber

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.135.1.53 ◽

2010 ◽

Vol 135 (1) ◽

pp. 53-58 ◽

Cited By ~ 22

Author(s):

Shengping Zhang ◽

Han Miao ◽

Xing-fang Gu ◽

Yuhong Yang ◽

Bingyan Xie ◽

...

Keyword(s):

Resistance Gene ◽

Ssr Markers ◽

Recombinant Inbred Lines ◽

Single Gene ◽

Inbred Lines ◽

Scab Resistance ◽

Chromosome 2 ◽

High Tunnel ◽

Prevalent Disease ◽

Group 2

Scab, caused by Cladosporium cucumerinum Ell. et Arthur, is a prevalent disease of cucumber (Cucumis sativus L.) worldwide. Scab can cause serious losses for cucumber production, especially in protected culture such as high tunnel production. Resistance to cucumber scab is dominant and is controlled by a single gene, Ccu. Breeding for resistant cultivars is the most efficient way to control the disease. Selection for resistance might be made easier if the gene were mapped to linked markers. Thus far, there are no tightly linked (genetic distance less than 1 cM) simple sequence repeat (SSR) markers for the Ccu gene, and no studies on mapping of the Ccu gene in cucumber using SSR markers. The objective of this study was to identify SSR markers for use in molecular breeding of scab resistance. In this study, we used a population of recombinant inbred lines (RILs). The population included 148 individuals derived from the cucumber inbred line 9110 Gt (Ccu Ccu) crossed with line 9930 (ccu ccu). The Ccu gene was mapped to linkage group 2, corresponding to chromosome 2 of cucumber. The flanking markers SSR03084 and SSR17631 were linked to the Ccu gene with distances of 0.7 and 1.6 cM, respectively. The veracity of SSR03084 and SSR17631 was tested using 59 diverse inbred lines and hybrids, and the accuracy rate for the two markers was 98.3%. In conclusion, two SSRs closely linked to scab resistance gene Ccu have been identified and can be used in a cucumber breeding program.

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QTLs for resistance to soybean cyst nematode, races 3, 9, and 14 in cultivar Hartwig

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x2011000400012 ◽

2011 ◽

Vol 46 (4) ◽

pp. 420-428 ◽

Cited By ~ 11

Author(s):

Marcia Flores da Silva Ferreira ◽

Gerardo Domingo Lucio Cervigni ◽

Adésio Ferreira ◽

Ivan Schuster ◽

Fernanda Abreu Santana ◽

...

Keyword(s):

Soybean Cyst Nematode ◽

Recombinant Inbred Lines ◽

Inbred Lines ◽

Cyst Nematode ◽

Minor Effect ◽

Phenotypic Variance ◽

Linkage Groups ◽

Resistance Qtls ◽

Epistatic Interactions ◽

Genomic Regions

The objective of this work was to identify major and minor-effect quantitative trait loci (QTL) for resistance to races 3, 9, and 14 of soybean cyst nematode (SCN) in Hartwig cultivar; to map new resistance QTLs for these races; and to check for the existence of epistatic interactions between QTLs. Cultivar Hartwig is an important resistance source to SCN. Recombinant inbred lines (RIL) obtained from a cross between 'Hartwig' (resistant) and Y23 (susceptible) were evaluated regarding resistance to the three races. New genomic regions for resistance to SCN were identified by microsatellites. Four QTLs, which explained between 12 and 34% of phenotypic variance, were detected for resistance to race 3 in linkage groups (LG) A2, G, J, and M. The QTL in LG G is also important for resistance to race 9. Epistatic interactions were detected between loci, which indicate resistance to races 9 and 14. There are high and low-effect resistance QTLs to SCN.

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