NC-GSB-524W, NC-GSB-527W, NC-GSB-528W, NC-GSB-530W, NC-GSB-531W, and NC-GSB-532W Watermelon Lines with Gummy Stem Blight Resistance and Good Fruit Quality

Abstract Key message We identified QTLs associated with gummy stem blight resistance in an interspecific F2:3Citrullus population and developed marker assays for selection of the loci in watermelon. Abstract Gummy stem blight (GSB), caused by three Stagonosporopsis spp., is a devastating fungal disease of watermelon (Citrullus lanatus) and other cucurbits that can lead to severe yield losses. Currently, no commercial cultivars with genetic resistance to GSB in the field have been reported. Utilizing GSB-resistant cultivars would reduce yield losses, decrease the high cost of disease control, and diminish hazards resulting from frequent fungicide application. The objective of this study was to identify quantitative trait loci (QTLs) associated with GSB resistance in an F2:3 interspecific Citrullus mapping population (N = 178), derived from a cross between Crimson Sweet (C. lanatus) and GSB-resistant PI 482276 (C. amarus). The population was phenotyped by inoculating seedlings with Stagonosporopsis citrulli 12178A in the greenhouse in two separate experiments, each with three replications. We identified three QTLs (ClGSB3.1, ClGSB5.1 and ClGSB7.1) associated with GSB resistance, explaining between 6.4 and 21.1% of the phenotypic variation. The genes underlying ClGSB5.1 includes an NBS-LRR gene (ClCG05G019540) previously identified as a candidate gene for GSB resistance in watermelon. Locus ClGSB7.1 accounted for the highest phenotypic variation and harbors twenty-two candidate genes associated with disease resistance. Among them is ClCG07G013230, encoding an Avr9/Cf-9 rapidly elicited disease resistance protein, which contains a non-synonymous point mutation in the DUF761 domain that was significantly associated with GSB resistance. High throughput markers were developed for selection of ClGSB5.1 and ClGSB7.1. Our findings will facilitate the use of molecular markers for efficient introgression of the resistance loci and development of GSB-resistant watermelon cultivars.

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Evaluation of Resistance to Gummy Stem Blight in a Population of Recombinant Inbred Lines of Watermelon × Citron

HortScience ◽

10.21273/hortsci15599-20 ◽

2021 ◽

pp. 1-9

Author(s):

Luis A. Rivera-Burgos ◽

Emily Silverman ◽

Nebahat Sari ◽

Todd C. Wehner

Keyword(s):

Disease Severity ◽

Fruit Quality ◽

Recombinant Inbred ◽

The United States ◽

Disease Assessment ◽

Quality Traits ◽

Plant Introductions ◽

Stem Blight ◽

Gummy Stem Blight ◽

Fruit Quality Traits

Gummy stem blight (GSB), a major disease caused by Stagonosporopsis cucurbitacearum (syn. Didymella bryoniae), has caused significant losses of watermelon in the United States. The lack of progress in the development of resistant cultivars is the result of complex inheritance of resistance and breeding strategies that rely on single-plant selection. Because the sources of resistance are wild watermelon relatives, good fruit quality has been difficult to maintain during the selection process. Three hundred recombinant inbred line (RILs) in a population that carries resistance genes to GSB as well as good fruit quality were produced. This was accomplished by crossing and intercrossing resistant plant introductions, crossing the resulting progenies with elite cultivars, intercrossing those progenies, and, finally, self-pollinating to the S3 generation. The 300 RILs were evaluated for disease severity and fruit morphological and quality traits under greenhouse and field conditions in a randomized complete block design with 10 replications and 3 years. The means and correlations for disease severity ratings and fruit quality traits were estimated. Approximately 186 RILs had disease severity ratings below the mean value of the disease assessment scale (4.5), indicating that they possibly carry one or more genes for resistance to GSB. All disease severity ratings were correlated to each other (r = 0.67–0.98; P < 0.001), but they were not correlated with fruit quality traits. Most importantly, several resistant RILs showed good to excellent fruit quality. Our results provide evidence of improved germplasm with high resistance and good fruit quality.

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A re-sequencing-based ultra-dense genetic map reveals a gummy stem blight resistance-associated gene in Cucumis melo

DNA Research ◽

10.1093/dnares/dsx033 ◽

2017 ◽

Vol 25 (1) ◽

pp. 1-10 ◽

Cited By ~ 17

Author(s):

Zhongyuan Hu ◽

Guancong Deng ◽

Haipeng Mou ◽

Yuhui Xu ◽

Li Chen ◽

...

Keyword(s):

Genetic Map ◽

Cucumis Melo ◽

Blight Resistance ◽

Stem Blight ◽

Gummy Stem Blight

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Screening of melon genotypes identifies gummy stem blight resistance associated with Gsb1 resistant loci

Journal of Plant Biotechnology ◽

10.5010/jpb.2018.45.3.217 ◽

2018 ◽

Vol 45 (3) ◽

pp. 217-227 ◽

Cited By ~ 2

Author(s):

Md Zahid Hassan ◽

Arif Hasan Khan Robin ◽

Md Abdur Rahim ◽

Sathishkumar Natarajan ◽

Hoy-Taek Kim ◽

...

Keyword(s):

Blight Resistance ◽

Stem Blight ◽

Gummy Stem Blight

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Molecular Tagging of Gummy Stem Blight Resistance in Watermelon

HortScience ◽

10.21273/hortsci.33.3.472e ◽

1998 ◽

Vol 33 (3) ◽

pp. 472e-472

Author(s):

Young-Seok Kwon ◽

Young Hyun Om ◽

Leigh Hawkins ◽

Fenny Dane

Keyword(s):

Plant Introduction ◽

Aflp Markers ◽

Blight Resistance ◽

Didymella Bryoniae ◽

Molecular Tagging ◽

Stem Blight ◽

Gummy Stem Blight ◽

Blight Disease ◽

Fungus Disease ◽

Selection Of

The fungus Didymella bryoniae causes gummy stem blight (foliar phase) and black rot (fruit phase) in cucurbits. As resistance to other diseases have been incorporated into cucurbits, losses due to gummy stem blight have increased. Populations derived from crosses between a cultivated watermelon (SS-4), susceptible to the fungus Didymella bryoniae and resistant plant introduction accessions (PI 189225 and PI 272778) are used to detect molecular markers linked to gummy stem blight disease resistance. Genomic DNA was purified from primary leaves of watermelon seedlings before seedlings were inoculated with a spore suspension of the fungus. Disease severity was rated 4 days after inoculation. DNA bulked from resistant or susceptible BC seedlings was amplified to detect AFLP markers. Linkages between gummy stem blight resistance and AFLP markers were identified and should facilitate evaluation and selection of watermelon populations segregating for gummy stem blight resistance.

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Factors Promoting Pycnidia Production of Didymella bryoniae, the Causal of Gummy Stem Blight in Cucurbits

Egyptian Journal of Phytopathology ◽

10.21608/ejp.2017.89736 ◽

2017 ◽

Vol 45 (1) ◽

pp. 173-187

Author(s):

Abdel-Fattah El-Wakil ◽

Amal Khalil ◽

Ibrahim El -Abbasi

Keyword(s):

Didymella Bryoniae ◽

Stem Blight ◽

Gummy Stem Blight

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QTL Mapping for Gummy Stem Blight Resistance in Watermelon (Citrullus spp.)

Plants ◽

10.3390/plants10030500 ◽

2021 ◽

Vol 10 (3) ◽

pp. 500

Author(s):

Eun Su Lee ◽

Do-Sun Kim ◽

Sang Gyu Kim ◽

Yun-Chan Huh ◽

Chang-Gi Back ◽

...

Keyword(s):

Chromosome 8 ◽

Chromosome 6 ◽

Potential Candidate ◽

Stem Blight ◽

Gummy Stem Blight ◽

F2 Population ◽

Leaf Lesion ◽

Phenotypic Variations ◽

A Minor ◽

Selection Of

Watermelon (Citrulluslanatus) is an economically important fruit crop worldwide. Gummy stem blight (GSB) is one of the most damaging diseases encountered during watermelon cultivation. In the present study, we identified quantitative trait loci (QTLs) associated with GSB resistance in an F2 population derived from a cross between maternal-susceptible line ‘920533’ (C. lanatus) and the paternal-resistant line ‘PI 189225’ (C. amarus). The resistance of 178 F2 plants was assessed by two different evaluation methods, including leaf lesion (LL) and stem blight (SB). To analyze the QTLs associated with GSB resistance, a linkage map was constructed covering a total genetic distance of 1070.2 cM. QTL analysis detected three QTLs associated with GSB resistance on chromosome 8 and 6. Among them, two QTLs, qLL8.1 and qSB8.1 on chromosome 8 identified as major QTLs, explaining 10.5 and 10.0% of the phenotypic variations localizing at same area and sharing the same top markers for both LL and SB traits, respectively. A minor QTL, qSB6.1, explains 9.7% of phenotypic variations detected on chromosome 6 only for the SB trait. High-throughput markers were developed and validated for the selection of resistant QTLs using watermelon accessions, and commercial cultivars. Four potential candidate genes were predicted associated with GSB resistance based on the physical location of flanking markers on chromosome 8. These findings will be helpful for the development of watermelon cultivars resistant to GSB.

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