QTL Mapping for Resistance to Early Blight in a Tetraploid Potato Population

Early blight of potato, caused by Alternaria solani, is an economically important foliar disease in most potato-growing regions. Growing cultivars with higher levels of resistance to early blight can reduce tuber yield losses and the need for fungicide applications. In this research, a bi-parental tetraploid potato population, segregating for resistance to early blight in leaves and tubers, was characterized to identify novel quantitative trait loci (QTL) associated with foliar and tuber early blight resistance. Assessment of the disease resistance in the foliage was performed by field evaluation and in tuber under controlled conditions. Results from this study revealed significant differences (P < 0.001) in resistance to A. solani among potato clones both in the leaves and in tubers. There was no statistically significant correlation (r = 0.06, P = 0.35) between the resistance scores from leaves and tubers. Several clones exhibited; however, high levels of resistance both in leaves and tubers and are; thus, promising candidates for breeding for early blight resistance. Linkage mapping revealed several QTL for early blight affecting both foliage and tubers. QTL associated with disease resistance in the tuber were found on chromosomes 1, 2, 3, 4, 8, 11 and 12. QTL associated with disease resistance in foliage were also examined for independence from defoliation, and independent QTL were; thus, found on chromosomes 5 and 11.

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Evaluation of tomato genotypes for early blight disease resistance caused by Alternaria solani in Pakistan

Journal of Plant Pathology ◽

10.1007/s42161-019-00304-8 ◽

2019 ◽

Vol 101 (4) ◽

pp. 1159-1170

Author(s):

Khalid Pervaiz Akhtar ◽

Najeeb Ullah ◽

Muhammad Yussouf Saleem ◽

Qumer Iqbal ◽

Muhammad Asghar ◽

...

Keyword(s):

Disease Resistance ◽

Early Blight ◽

Alternaria Solani ◽

Blight Disease ◽

Tomato Genotypes

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Greenhouse Disease Screen Facilitates Breeding Resistance to Tomato Early Blight

HortScience ◽

10.21273/hortsci.25.2.222 ◽

1990 ◽

Vol 25 (2) ◽

pp. 222-223 ◽

Cited By ~ 5

Author(s):

Randokh G. Gardner

Keyword(s):

Lycopersicon Esculentum ◽

Field Trial ◽

Early Blight ◽

Alternaria Solani ◽

Blight Resistance ◽

Stem Lesion ◽

Foliar Resistance

An F2 population segregating for tomato (Lycopersicon esculentum Mill.) early blight resistance derived from C1943 was screened in the greenhouse by spray-inoculating conidia of Alternaria solani (Ellis and Martin) Jones and Grout onto stems of 6-week-old seedlings. Selected F3 lines derived from F2 plants with resistant, intermediate, and susceptible stem lesion reactions were grown in a replicated field trial and evaluated for foliar early blight resistance. Stem lesion and foliar resistance were closely associated, making the greenhouse screen for stem lesion resistance useful in identifying plants with foliar resistance.

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Resistance to Phytophthora infestans Clonal Lineage US-23 in Potato Cultivars and Its Relationship with Early Blight Resistance and Tuber Yield

Plant Disease ◽

10.1094/pdis-03-21-0594-re ◽

2021 ◽

Author(s):

Weiya Xue ◽

Kathleen G. Haynes ◽

Xinshun Qu

Keyword(s):

Late Blight ◽

Phytophthora Infestans ◽

Early Blight ◽

Tuber Yield ◽

Late Blight Resistance ◽

Field Trials ◽

Potato Cultivars ◽

Blight Resistance ◽

Clonal Lineage ◽

Progress Curve

Resistance to late blight, caused by Phytophthora infestans clonal lineage US-23, in 217 old and modern potato cultivars was evaluated in field trials in 2016 and 2017 in Pennsylvania. Significant differences in resistance were found among these cultivars (P < 0.0001). Significant interaction between cultivars and environments was found (P < 0.0001). The values of relative area under the disease progress curve ranged from 0 to 0.5841 in 2016 and from 0 to 0.5469 in 2017. Broad-sense heritability of late blight resistance was estimated to be 0.91 with a 95% confidence interval of 0.88 to 0.93. Cluster analysis classified the cultivars into 5 groups: resistant, moderately resistant, intermediate, moderately susceptible, and susceptible. Thirty cultivars showing resistance and 32 cultivars showing moderate resistance were identified. The 217 cultivars were also evaluated for foliar maturity, tuber yield and resistance to early blight, caused by Alternaria solani. A few cultivars with late blight resistance independent of late maturity were found. Late blight resistance and early blight resistance were positively correlated, and 17 cultivars possessed resistance to both diseases. Yield tradeoff associated with late blight resistance was not observed among the cultivars in the absence of disease pressure.

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Search for sources of early blight (Alternaria solani) field resistance not associated with vegetative late maturity in tetraploid potato germplasm

Euphytica ◽

10.1007/bf01677862 ◽

1995 ◽

Vol 83 (1) ◽

pp. 63-70 ◽

Cited By ~ 14

Author(s):

L. S. Boiteux ◽

F. J. B. Reifschneider ◽

M. E. N. Fonseca ◽

J. A. Buso

Keyword(s):

Early Blight ◽

Alternaria Solani ◽

Field Resistance ◽

Tetraploid Potato ◽

Potato Germplasm ◽

Late Maturity

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Effect of strobilurin fungicides on control of early blight (Alternaria solani) and yield of potatoes grown under two N fertility regimes

Phytoprotection ◽

10.7202/016397ar ◽

2007 ◽

Vol 88 (1) ◽

pp. 9-15 ◽

Cited By ~ 8

Author(s):

William MacDonald ◽

Rick D. Peters ◽

Robert H. Coffin ◽

Christian Lacroix

Keyword(s):

Prince Edward Island ◽

Early Blight ◽

Tuber Yield ◽

Alternaria Solani ◽

Field Trials ◽

Potato Yield ◽

Russet Burbank ◽

Strobilurin Fungicides ◽

N Fertility

Early blight, caused by Alternaria solani, is a ubiquitous disease that can reduce potato yield. Adequate crop fertility and appropriate fungicide applications usually suppress the development of this disease. Field trials were established in Prince Edward Island to determine whether strobilurin analogs, namely azoxystrobin and pyraclostrobin, could suppress early blight of potatoes (cvs. Shepody and Russet Burbank) grown under two nitrogen (N) fertility regimes (high or low N). Azoxystrobin and pyraclostrobin were linked to significantly higher total tuber yield for Russet Burbank in 2003 and Shepody in 2004 when compared to plots receiving no strobilurin fungicides. No significant differences in total tuber yield based on N fertility were observed, although the high N rate decreased disease in Russet Burbank control plots in 2004. Due to an absence of early blight in 2003, the increase in Russet Burbank yield may be attributed to the physiological and developmental alterations brought about by strobilurin products in treated plants. In 2004, early blight was severe in inoculated control plots, but it was significantly suppressed in plots having received azoxystrobin or pyraclostrobin, regardless of the cultivar type or fertility regime. Therefore, to prevent unnecessary N inputs, growers need to supply only the necessary N amount to optimize tuber yields and manage early blight with fungicides.

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QTL associated with gummy stem blight resistance in watermelon

Theoretical and Applied Genetics ◽

10.1007/s00122-020-03715-9 ◽

2020 ◽

Author(s):

Winnie Gimode ◽

Kan Bao ◽

Zhangjun Fei ◽

Cecilia McGregor

Keyword(s):

Disease Resistance ◽

Phenotypic Variation ◽

Citrullus Lanatus ◽

Genetic Resistance ◽

Blight Resistance ◽

Yield Losses ◽

Stem Blight ◽

Gummy Stem Blight ◽

Cost Of Disease ◽

Selection Of

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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QTL identification for early blight resistance (Alternaria solani) in a Solanum lycopersicum × S. arcanum cross

Theoretical and Applied Genetics ◽

10.1007/s00122-006-0442-8 ◽

2006 ◽

Vol 114 (3) ◽

pp. 439-450 ◽

Cited By ~ 17

Author(s):

R. Chaerani ◽

M. J. M. Smulders ◽

C. G. van der Linden ◽

B. Vosman ◽

P. Stam ◽

...

Keyword(s):

Solanum Lycopersicum ◽

Early Blight ◽

Alternaria Solani ◽

Blight Resistance ◽

Qtl Identification

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Resistance to Alternaria solani in Hybrids Between a Solanum tuberosum Haploid and S. raphanifolium

Phytopathology ◽

10.1094/phyto-05-11-0146 ◽

2012 ◽

Vol 102 (2) ◽

pp. 214-221 ◽

Cited By ~ 8

Author(s):

B. N. Weber ◽

S. H. Jansky

Keyword(s):

Solanum Tuberosum ◽

Wild Species ◽

Early Blight ◽

Genetic Resistance ◽

Alternaria Solani ◽

Economic Loss ◽

Blight Resistance ◽

Production Region ◽

Yield And Quality ◽

Progress Curve

Early blight of potato (Solanum tuberosum), caused by the foliar fungal pathogen Alternaria solani, is a major cause of economic loss in many potato-growing regions. Genetic resistance offers an opportunity to decrease fungicide usage while maintaining yield and quality. In this study, an early blight resistant clone of the diploid wild species S. raphanifolium was crossed as a male to a haploid (2n=2x) of cultivated potato. Hybrids were backcrossed to both parents. Eight families were created and evaluated for early blight resistance in the field. Families created by backcrossing to the wild species parent exhibited significantly lower relative area under the disease progress curve means than those from backcrossing to the cultivated parent, leading to the conclusion that S. raphanifolium contributes genes for early blight resistance. The mechanism of resistance in S. raphanifolium is unique because A. solani could not be recovered from lesions. Clones were identified with high levels of resistance and adaptation to the photoperiod of a temperate production region.

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Field Evaluation of 64 Apple Rootstocks for Orchard Performance and Fire Blight Resistance

HortScience ◽

10.21273/hortsci.42.7.1517 ◽

2007 ◽

Vol 42 (7) ◽

pp. 1517-1525 ◽

Cited By ~ 33

Author(s):

Nicole L. Russo ◽

Terence L. Robinson ◽

Gennaro Fazio ◽

Herb S. Aldwinckle

Keyword(s):

Disease Resistance ◽

Root Rot ◽

Financial Risk ◽

Fire Blight ◽

Field Evaluation ◽

Field Trials ◽

Blight Resistance ◽

Apple Rootstocks ◽

Yield Efficiency ◽

Better Than

In 2002, apple rootstock trials using three scion cultivars were established at Geneva, NY, to evaluate 64 apple (Malus ×domestica Borkh.) rootstocks for horticultural performance and fire blight resistance. Field trials compared several elite Geneva® apple rootstocks, which were bred for tolerance to fire blight and Phytophthora root rot, to both commercial standards and elite rootstock clones from around the world. Three rootstocks performed well with all scion cultivars: ‘B.9’, ‘Geneva® 935’, and ‘Geneva® 41’. All three rootstocks were similar in size to ‘M.9’ clones but with elevated yield efficiency and superior resistance to fire blight. ‘Geneva® 11’ also performed very well with ‘Golden Delicious’ and ‘Honeycrisp’ with regard to yield efficiency and disease resistance. Resistant rootstocks greatly enhanced the survival of young trees, particularly with the susceptible scion cultivars ‘Gala’ and ‘Honeycrisp’. Results demonstrate the ability of new rootstock clones to perform better than current commercial standards, reducing financial risk to producers while promoting orchard health with enhanced disease resistance.

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