Differential Susceptibility of 39 Tomato Varieties to Phytophthora infestans Clonal Lineage US-23

During the summers of 2012 and 2013, 39 tomato (Solanum lycopersicum) lines or varieties were evaluated for resistance to late blight in three separate field trials. In each trial, late blight was caused by field isolates of Phytophthora infestans clonal lineage US-23. Varieties with the late blight resistance genes Ph-1, Ph-2, Ph-3, and Ph-2 + Ph-3 were included, along with several heirloom varieties with grower-reported resistance and varieties with no known resistance. All six varieties with Ph-2 + Ph-3, along with NC25P, which is homozygous for Ph-3 only, showed a high level of resistance. Plum Regal F1, which is heterozygous for Ph-3 only, showed moderate resistance. Legend, the only variety with Ph-2 alone, also showed moderate resistance. Three heirloom varieties, Matt's Wild Cherry, Lemon Drop, and Mr. Stripey, showed a high level of resistance comparable with that of varieties with Ph-2 + Ph-3. New Yorker, possessing Ph-1 only, showed no resistance. Indeterminate varieties had significantly less disease than determinate varieties in two of the three trials. Overall, this study suggests that tomato varieties with both Ph-2 and Ph-3 can be used to effectively manage late blight caused by P. infestans clonal lineage US-23. Varieties possessing only Ph-2, or heterozygous for Ph-3, were better protected than those without any late blight resistance but might still require supplemental fungicide applications, while the variety that was homozygous for Ph-3 was highly resistant. Several heirloom varieties were also highly resistant, and the unknown mechanism of their resistance warrants further research. Finally, the plasticity observed in United States P. infestans populations over the past several decades necessitates continued monitoring for genetic changes within P. infestans that could lead to the breakdown of resistance reported here.

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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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Virulence of Phytophthora infestans isolates from potato in Spain

Plant Protection Science ◽

10.17221/39/2021-pps ◽

2021 ◽

Vol 57 (No. 4) ◽

pp. 279-288

Author(s):

Jose Ignacio Ruiz de Galarreta ◽

Alba Alvarez-Morezuelas ◽

Nestor Alor ◽

Leire Barandalla ◽

Enrique Ritter

Keyword(s):

Late Blight ◽

Phytophthora Infestans ◽

Late Blight Resistance ◽

Blight Resistance ◽

Genetic Changes ◽

Detached Leaves ◽

Severity Of The Disease ◽

Pathogen Populations ◽

Incompatibility Reactions

The oomycete Phytophthora infestans is responsible for the disease known as late blight in potato and tomato. It is the plant pathogen that has caused the greatest impact on humankind so far and, despite all the studies that have been made, it remains the most important in this crop. In Spain during the last years a greater severity of the disease has been observed in both, potato and tomato, probably due to genetic changes in pathogen populations described recently. The aim of this study was the characterization of the physiological strains of 52 isolates of P. infestans obtained in different potato-growing areas in Spain. For this purpose, inoculations on detached leaves were performed in order to determine compatibility or incompatibility reactions. A total of 17 physiological races were found. The less frequent virulence factors were Avr5 and Avr8. By studying the epidemiology of the pathogen, a specific breeding program for late blight resistance can be implemented.

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Competition between Phytophthora infestans Effectors Leads to Increased Aggressiveness on Plants Containing Broad-Spectrum Late Blight Resistance

PLoS ONE ◽

10.1371/journal.pone.0010536 ◽

2010 ◽

Vol 5 (5) ◽

pp. e10536 ◽

Cited By ~ 40

Author(s):

Dennis A. Halterman ◽

Yu Chen ◽

Jiraphan Sopee ◽

Julio Berduo-Sandoval ◽

Amilcar Sánchez-Pérez

Keyword(s):

Late Blight ◽

Phytophthora Infestans ◽

Broad Spectrum ◽

Late Blight Resistance ◽

Blight Resistance

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Performance of Transgenic Potato Containing the Late Blight Resistance Gene RB

Plant Disease ◽

10.1094/pdis-92-3-0339 ◽

2008 ◽

Vol 92 (3) ◽

pp. 339-343 ◽

Cited By ~ 52

Author(s):

Dennis A. Halterman ◽

Lara Colton Kramer ◽

Susan Wielgus ◽

Jiming Jiang

Keyword(s):

Late Blight ◽

Resistance Gene ◽

Late Blight Resistance ◽

Transgenic Potato ◽

Field Trials ◽

Blight Resistance ◽

Solanum Bulbocastanum ◽

Wild Potato Species ◽

Foliar Resistance ◽

In The Wild

Late blight of potato, caused by Phytophthora infestans, is one of the most devastating diseases of potato. A major late blight resistance gene, called RB, previously was identified in the wild potato species Solanum bulbocastanum through map-based cloning. The full-length gene coding sequence, including the open reading frame and promoter, has been integrated into cultivated potato (S. tuberosum) using Agrobacterium-mediated transformation. RB-containing transgenic plants were challenged with P. infestans under optimal late blight conditions in greenhouse experiments. All transgenic lines containing RB exhibited strong foliar resistance. Field-grown transgenic tubers also were tested for resistance to P. infestans. In contrast to the foliar resistance phenotype, RB-containing tubers did not exhibit increased resistance. Two years of field trials were used to ascertain whether the presence of RB had any effect on tuber yield. We were unable to detect any significant effect on tuber size or yield after addition of the resistance gene to several S. tuberosum cultivars.

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Transfer to Processing Tomato and Characterization of Late Blight Resistance Derived from Solanum pimpinellifolium L. L3708

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.130.6.877 ◽

2005 ◽

Vol 130 (6) ◽

pp. 877-884 ◽

Cited By ~ 27

Author(s):

Min-Jea Kim ◽

Martha A. Mutschler

Keyword(s):

New York ◽

Late Blight ◽

Single Gene ◽

Late Blight Resistance ◽

Field Trials ◽

Blight Resistance ◽

Segregation Data ◽

Processing Tomato ◽

Breeding Populations ◽

Infested Field

Late blight [caused by Phytophthora infestans (Mont.) de Bary] causes severe loss of tomato [Solanum lycopersicum L. (formerly Lycopersicon esculentum Mill.)] production in environments favorable to the pathogen. Researchers at the Asia Vegetable Research Development Center (AVRDC) identified resistance to late blight in an accession of S. pimpinellifolium [formerly L. pimpinellifolium (L.) Mill.] that they named accession L3708. This resistance has now been transferred to processing tomato lines, which are resistant to multiple P. infestans isolates. Lab trials, inoculated field trials in New York, and naturally infested field trials in Mexico all indicate that these processing tomato lines are fixed for late blight resistance. Segregation data obtained for resistance in the breeding populations were dependent on the pathogen isolate used for the disease screen. Segregation data do not support the hypothesis of single gene control of the full resistance trait, but instead suggest that more than one gene is involved, and that these genes interact in an epistatic manner.

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STUDIES ON FERTILITY AND LATE BLIGHT RESISTANCE IN SOLANUM BULBOCASTANUM DUN. IN MEXICO

Canadian Journal of Botany ◽

10.1139/b59-003 ◽

1959 ◽

Vol 37 (1) ◽

pp. 41-49 ◽

Cited By ~ 21

Author(s):

K. M. Graham ◽

J. S. Niederhauser ◽

Leopoldo Servin

Keyword(s):

Late Blight ◽

Phytophthora Infestans ◽

Late Blight Resistance ◽

Field Resistance ◽

Blight Resistance ◽

Solanum Bulbocastanum ◽

Mexican Isolate

Solanum balbocastanum Dun. was collected extensively throughout its range in Mexico and Guatemala. Experimental self- and cross-pollinations showed that the species is highly self-sterile and consists of cross-sterile and cross-fertile individuals. Self-sterility may be due to the presence of incompatibility factors or to triploidy. Authentic hybrids were produced between S. bulbocastanum and S. trifidum Correll, and between S. bulbocastanum and S. pinnatisectum Dun.After inoculation with race 1.2.3.4 of Phytophthora infestans three types of reaction were observed among 1148 seedlings of S. bulbocastanum: immunity with no perceptible lesions, resistance expressed by non-sporulating lesions of the hypersensitive type, and susceptibility indicated by large sporulating necrotic lesions. Seedlings resistant to an isolate of race 1.2.3.4 of Canadian origin did not always show the same level of resistance to a Mexican isolate of the same race. Varying degrees of field resistance were observed among seedling plants, while tuber-propagated plants were generally field immune. Solanum bulbocastanum is considered a mixture of resistant and susceptible genotypes.

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Reassessment of QTLs for Late Blight Resistance in the Tomato Accession L3708 Using a Restriction Site Associated DNA (RAD) Linkage Map and Highly Aggressive Isolates of Phytophthora infestans

PLoS ONE ◽

10.1371/journal.pone.0096417 ◽

2014 ◽

Vol 9 (5) ◽

pp. e96417 ◽

Cited By ~ 25

Author(s):

Ai-Lin Chen ◽

Chu-Yin Liu ◽

Chien-Hua Chen ◽

Jaw-Fen Wang ◽

Yu-Chen Liao ◽

...

Keyword(s):

Late Blight ◽

Phytophthora Infestans ◽

Linkage Map ◽

Restriction Site ◽

Late Blight Resistance ◽

Blight Resistance

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Expression of the Potato Late Blight Resistance Gene Rpi-phu1 and Phytophthora infestans Effectors in the Compatible and Incompatible Interactions in Potato

Phytopathology ◽

10.1094/phyto-09-16-0328-r ◽

2017 ◽

Vol 107 (6) ◽

pp. 740-748 ◽

Cited By ~ 9

Author(s):

Emil Stefańczyk ◽

Sylwester Sobkowiak ◽

Marta Brylińska ◽

Jadwiga Śliwka

Keyword(s):

Late Blight ◽

Phytophthora Infestans ◽

Expression Patterns ◽

Late Blight Resistance ◽

Blight Resistance ◽

Transcriptional Level ◽

R Genes ◽

Transcript Accumulation ◽

Breeding Lines ◽

Additional Resistance

This study describes late blight resistance of potato breeding lines resulting from crosses between cultivar ‘Sárpo Mira’ and Rpi-phu1 gene donors. The progeny is investigated for the presence of Rpi-Smira1 and Rpi-phu1 resistance (R) genes. Interestingly, in detached-leaflet tests, plants with both R genes withstood the infection of the Phytophthora infestans isolate virulent to each gene separately, due to either interaction of these genes or the presence of additional resistance loci. The interaction was studied further in three chosen breeding lines on the transcriptional level. The Rpi-phu1 expression, measured over 5 days, revealed different patterns depending on the outcome of the interaction with P. infestans: it increased in infected plants whereas it remained low and stable when infection was unsuccessful. The expression patterns of P. infestans effectors Avr-vnt1, AvrSmira1, and Avr8, recognized by the Rpi-phu1, Rpi-Smira1, and Rpi-Smira2 genes, respectively, were evaluated in the same experimental setup. This is the first report that the Avr-vnt1 effector expression is not switched off permanently in virulent isolates to avoid recognition by an R protein but can reappear in a postbiotrophic phase and is present constantly when infecting plants without the corresponding R gene. Both a plant and a pathogen can react to the other interacting side by changing the transcript accumulation of R genes or effectors.

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Inheritance of Alternaria Late Blight Resistance in Pistachio

HortScience ◽

10.21273/hortsci.32.3.494c ◽

1997 ◽

Vol 32 (3) ◽

pp. 494C-494

Author(s):

Chih-Cheng T. Chao ◽

Themis J. Michailides ◽

Dan E. Parfitt

Keyword(s):

Late Blight ◽

High Resistance ◽

Alternaria Alternata ◽

Late Blight Resistance ◽

Breeding Population ◽

Blight Resistance ◽

Improvement Program ◽

Resistant Cultivars ◽

Greenhouse Evaluation ◽

Moderate Resistance

Alternaria late blight of pistachio caused by Alternaria alternata, has become a serious problem in pistachio orchards in California. As part of the California pistachio improvement program, we evaluated the resistance/susceptibility of the breeding progenies to Alternaria late blight at two locations. The heritability of resistance ranged from 0.35 to 0.38 based on half-sib progenies analysis. Open-pollinated (OP) progenies from three cultivars showed moderate to high resistance. Greenhouse inoculation confirmed that OP progenies of cultivars Bronte and Trabonella had the greatest resistance. OP progenies of cultivar Red Aleppo were highly susceptible in greenhouse inoculations compared to moderate resistance found in field evaluations. OP progenies of the only commercial cultivar Kerman in California were susceptible in both field and greenhouse evaluation. The results show the potential for development of resistant cultivars is available in the breeding population of the California pistachio improvement program.

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