scholarly journals Resistance to Crown and Root Rot Caused by Phytophthora capsici in a Tomato Advanced Backcross of Solanum habrochaites and Solanum lycopersicum

Plant Disease ◽  
2016 ◽  
Vol 100 (4) ◽  
pp. 829-835 ◽  
Author(s):  
L. M. Quesada-Ocampo ◽  
A. M. Vargas ◽  
R. P. Naegele ◽  
D. M. Francis ◽  
M. K. Hausbeck
Keyword(s):  
Root Rot ◽  
Phytophthora Capsici ◽  
Defense Responses ◽  
Vegetable Crops ◽  
Backcross Population ◽  
Phytophthora Root Rot ◽  
Disease Response ◽  
Advanced Backcross ◽  
Solanum Habrochaites ◽  
Crown And Root Rot

Phytophthora capsici causes devastating disease on many vegetable crops, including tomato and other solanaceous species. Solanum habrochaites accession LA407, a wild relative of cultivated tomato, has shown complete resistance to four P. capsici isolates from Michigan cucurbitaceous and solanaceous crops in a previous study. Greenhouse experiments were conducted to evaluate 62 lines of a tomato inbred backcross population between LA407 and the cultivated tomato ‘Hunt 100’ and ‘Peto 95-43’ for resistance to two highly virulent P. capsici isolates. Roots of 6-week-old seedlings were inoculated with each of two P. capsici isolates and maintained in the greenhouse. Plants were evaluated for wilting and plant death three times per week for 5 weeks. Significant differences were observed in disease response among the inbred tomato lines. Most lines evaluated were susceptible to P. capsici isolate 12889 but resistant to isolate OP97; 24 tomato lines were resistant to both isolates. Heritability of Phytophthora root rot resistance was high in this population. Polymorphic molecular markers located in genes related to resistance and defense responses were identified and added to a genetic map previously generated for the population. Resistant lines and polymorphic markers identified in this study are a valuable resource for development of tomato varieties resistant to P. capsici.

scholarly journals Resistance of Pepper to Phytophthora Crown, Root, and Fruit Rot Is Affected by Isolate Virulence

Plant Disease ◽  
2010 ◽  
Vol 94 (1) ◽  
pp. 24-30 ◽  
Author(s):  
J. M. Foster ◽  
M. K. Hausbeck
Keyword(s):  
Root Rot ◽  
Laboratory Experiments ◽  
Phytophthora Capsici ◽  
Fruit Rot ◽  
Hot Pepper ◽  
Cultivar Resistance ◽  
Breeding Lines ◽  
Pepper Fruit ◽  
Millet Seed ◽  
Crown And Root Rot

Greenhouse and laboratory experiments were conducted to determine the virulence of four Phytophthora capsici isolates from Michigan to 31 bell and hot pepper cultivars and breeding lines. Resistance to crown and root rot was assessed following the inoculation of soilless media with P. capsici–infested millet seed. In a detached fruit assay, fruit rot resistance was evaluated following inoculation with zoospore suspensions of 1.75 × 106 zoospores/ml. The four isolates differed in virulence to pepper lines screened for crown and root rot resistance and were considered to be four different physiological races. The pepper lines CM334, NY07-8001, NY07-8006, and NY07-8007 were resistant to the isolates tested. None of the commercial cultivars were resistant to P. capsici isolate 12889, but several cultivars were resistant to the other isolates screened. The isolates varied in their ability to cause infection on the fruits of the different cultivars. Overall, pepper fruit were more susceptible to P. capsici than the roots and crowns. Management of Phytophthora crown and root rot of pepper can be improved through the use of resistant cultivars. However, since isolate virulence affects resistance, cultivar resistance will need to be utilized on a local scale accordingly.

scholarly journals Performance and Resistance to Phytophthora Crown and Root Rot in Squash Lines

2020 ◽  
Vol 30 (5) ◽  
pp. 608-618 ◽  
Author(s):  
Kyle E. LaPlant ◽  
Gregory Vogel ◽  
Ella Reeves ◽  
Christine D. Smart ◽  
Michael Mazourek
Keyword(s):  
Root Rot ◽  
Cucurbita Pepo ◽  
Field Experiments ◽  
Phytophthora Capsici ◽  
Severe Disease ◽  
Field Trials ◽  
Disease Symptoms ◽  
Resistant Lines ◽  
Oomycete Pathogen ◽  
Crown And Root Rot

Phytophthora crown and root rot, caused by the oomycete pathogen Phytophthora capsici, is a devastating disease of squash and pumpkin (Cucurbita pepo). No currently available cultivars provide complete resistance to this disease. Three newly developed squash lines and four hybrids were evaluated in greenhouse and field experiments for their resistance to phytophthora crown and root rot as well as for their horticultural performance. The three newly developed lines ranked among the most resistant entries included in 2 years of field trials. In addition, in a separate greenhouse experiment, one of the lines was shown to display the least severe disease symptoms among a group of accessions previously reported to possess partial resistance to phytophthora crown and root. Furthermore, the resistance was observed to be robust to several isolates of P. capsici. However, the phytophthora-resistant lines had reduced yield relative to standard squash cultivars. These lines are useful for continued breeding efforts toward a phytophthora crown and root rot-resistant cultivar.

scholarly journals Genetic Analysis of Phytophthora Root Rot Race-specific Resistance in Chile Pepper

2008 ◽  
Vol 133 (6) ◽  
pp. 825-829 ◽  
Author(s):  
Ariadna Monroy-Barbosa ◽  
Paul W. Bosland
Keyword(s):  
Root Rot ◽  
Recombinant Inbred Lines ◽  
Single Gene ◽  
Phytophthora Capsici ◽  
Segregation Ratio ◽  
Descent Method ◽  
Chile Pepper ◽  
Phytophthora Root Rot ◽  
Multiple Alleles ◽  
Seven Generations

Phytophthora capsici Leon., causal agent of phytophthora root rot, is one of the most devastating pathogens attacking chile pepper (Capsicum annuum L.) plants. Many studies have tried to better understand phytophthora resistance, but the genetic behavior is not completely understood. To determine if phytophthora root rot resistance in chile pepper is controlled by multiple alleles at a few loci, or multiple genes at different loci, five recombinant inbred lines (RILs) were evaluated. The resistant accession, Criollo de Morelos-334, and the susceptible cultivar, Early Jalapeno, were hybridized to develop multiple RILs. After seven generations of selfing using the single seed descent method, four RILs were selected based on their phenotypic response to inoculation by five P. capsici isolates. The RILs were hybridized to each other to obtain F1 and F2 populations. The F2 populations were inoculated with single and a pair of races of P. capsici. When the F2 populations were inoculated with a single race, ratios of three resistant:one susceptible were obtained in the majority of the populations, indicating the action of an independent single gene. When the F2 populations were inoculated with a combination of two races, segregation ratios of 15 resistant:one susceptible were observed in two populations out of the four populations. The presence of susceptible individuals in all of the F2 population indicates that the resistant genes for the different P. capsici races are located at different loci. However, the rejection of the segregation ratio in one of the F2 population under a single race inoculation and in two of the F2 populations challenged with a combination of two races suggest a linkage phenomenon between some of the R genes. None of the RILs evaluated in this study displayed allelism for phytophthora root rot resistance.

Ultrastructural changes in roots of peppers resistant and susceptible to Phytophthora capsici

1995 ◽  
Vol 53 ◽  
pp. 982-983
Author(s):  
H. Ilarslan ◽  
A.S. Ustun ◽  
R. Yilmazer
Keyword(s):  
Root Rot ◽  
Host Plants ◽  
Phytophthora Capsici ◽  
Host Cells ◽  
Ultrastructural Changes ◽  
Ultrastructural Examination ◽  
Susceptible Host ◽  
Ultrastructural Studies ◽  
Foliar Blight ◽  
Crown And Root Rot

The infection by Phytophthora capsici Leonian causes foliar blight and crown and root rot of pepper plants. The ultrastructural examination of resistant and susceptible host-pathogen interactions was conducted in the pepper cultivars Ince Sivri-35, PM217, and PM702=CM 334 following inoculation with Phytophthora capsici. Responses were characterized and compared with healthy non-inoculated controls at 2,4 and 6 days after inoculation. Numerous ultrastructural studies have been made of the interaction of various host plants Phytophthora spp. No ultrastructural studies comparing the resistant and susceptible reactions of pepper cultivars to P. capsici. have been reported. It is important to examine the ultrastructural changes in inoculated and infected tissue of resistant and susceptible pepper cultivars to P. capsici. Information reported here characterizes the processes of pathogen containment in resistant interactions and compares these with the processes occuring in susceptible interactions.After 2 days in susceptible interactions, the pathogen grew intercellularly in roots, whereas in resistant interactions only a few intercellular hyphae were observed penetrating the host cells and forming haustoria.

scholarly journals Inheritance of Phytophthora Root Rot and Foliar Blight Resistance in Pepper

1999 ◽  
Vol 124 (1) ◽  
pp. 14-18 ◽  
Author(s):  
Stephanie J. Walker ◽  
Paul W. Bosland
Keyword(s):  
Root Rot ◽  
Phytophthora Capsici ◽  
Dominant Gene ◽  
Segregation Ratio ◽  
Stem Cutting ◽  
Blight Resistance ◽  
Phytophthora Root Rot ◽  
Resistant Parent ◽  
Foliar Blight ◽  
Foliar Resistance

The inheritance of resistance to Phytophthora capsici Leonian root rot and foliar blight was compared in two different Capsicum annuum L. var. annuum pod types. The seedling was screened for phytophthora root rot, while a genetically identical stem cutting was screened for phytophthora foliar blight to determine if the same gene(s) confer resistance to both disease syndromes. The susceptible parents were `Keystone Resistant Giant #3' (`Keystone'), a bell pepper type, and `Early Jalapeño', while `Criollo de Morelos-334' was the resistant parent. Resistance was observed in both F1 populations screened for phytophthora root and foliar infection indicating dominance for resistance. Reciprocal effects were not detected. To determine if the same gene(s) conferred root rot and foliar resistance, root rot screening results were matched to the corresponding foliar blight stem cutting reaction. The segregation of resistance in the F2 generations was dependent on the susceptible parent. In the F2 generation derived from `Early Jalapeño', root rot resistance and foliar blight resistance segregated in a 9:3:3:1 (root resistant/foliar resistant: root resistant/foliar susceptible: root susceptible/foliar resistant: root susceptible/foliar susceptible) ratio. One independent, dominant gene was necessary for root rot resistance, and a different independent, dominant gene was needed for foliar blight resistance. In the F2 generation derived from `Keystone', root rot and foliar blight resistance segregated in a 7:2:2:5 (root resistant/foliar resistant: root resistant/foliar susceptible: root susceptible/foliar resistant: root susceptible/foliar susceptible) ratio. This segregation ratio is expected when one dominant gene is required for root resistance, and a different dominant gene is required for foliar resistance. In addition to these two genes, at least one dominant allele of a third gene must be present for expression of root rot and foliar blight resistance.

scholarly journals First Report of Phytophthora capsici Causing Wilting and Crown and Root Rot on Eggplant (Solanum melongena) in Southeastern Spain

Plant Disease ◽  
2018 ◽  
Vol 102 (10) ◽  
pp. 2044-2044
Author(s):  
M. de Cara ◽  
A. Ayala-Doñas ◽  
A. Aguilera-Lirola ◽  
E. Badillo-López ◽  
J. Gómez-Vázquez
Keyword(s):  
Root Rot ◽  
Phytophthora Capsici ◽  
Solanum Melongena ◽  
First Report ◽  
Southeastern Spain ◽  
Crown And Root Rot

scholarly journals Screening of Cucurbita moschata Duchesne Germplasm for Crown Rot Resistance to Floridian Isolates of Phytophthora capsici Leonian

HortScience ◽  
2011 ◽  
Vol 46 (4) ◽  
pp. 536-540 ◽  
Author(s):  
Dario J. Chavez ◽  
Eileen A. Kabelka ◽  
José X. Chaparro
Keyword(s):  
Root Rot ◽  
Phytophthora Capsici ◽  
Crown Rot ◽  
Fruit Rot ◽  
Cucurbita Moschata ◽  
Breeding Lines ◽  
Foliar Blight ◽  
Disease Rating ◽  
Crown And Root Rot ◽  
Highly Virulent

Phytophthora capsici causes seedling death, crown and root rot, fruit rot, and foliar blight on squash and pumpkins (Cucurbita spp. L.). A total of 119 C. moschata accessions, from 39 geographic locations throughout the world, and a highly susceptible butternut squash cultivar, Butterbush, were inoculated with a suspension of three highly virulent P. capsici isolates from Florida to identify resistance to crown rot. Mean disease rating (DR) of the C. moschata collection ranged from 1.4 to 5 (0 to 5 scale with 0 resistant and 5 susceptible). Potential resistant and tolerant individuals were identified in the C. moschata collection. A set of 18 PIs from the original screen were rescreened for crown rot resistance. This rescreen produced similar results as the original screen (r = 0.55, P = 0.01). The accessions PI 176531, PI 458740, PI 442266, PI 442262, and PI 634693 were identified with lowest rates of crown infection with a mean DR less than 1.0 and/or individuals with DR = 0. Further selections from these accessions could be made to develop Cucurbita breeding lines and cultivars with resistance to crown rot caused by P. capsici.

scholarly journals Race Characterization of Phytophthora Root Rot on Capsicum in Taiwan as a Basis for Anticipatory Resistance Breeding

2018 ◽  
Vol 108 (8) ◽  
pp. 964-971 ◽  
Author(s):  
Derek W. Barchenger ◽  
Zong-Ming Sheu ◽  
Sanjeet Kumar ◽  
Shih-Wen Lin ◽  
Rishi R. Burlakoti ◽  
...  
Keyword(s):  
Mating Type ◽  
Root Rot ◽  
Recombinant Inbred Lines ◽  
Local Level ◽  
Phytophthora Capsici ◽  
Resistance Breeding ◽  
Global Scale ◽  
Phytophthora Root Rot ◽  
Universal System ◽  
New Races

Peppers (Capsicum sp.) are an increasingly important crop because of their use as a vegetable, spice, and food colorant. The oomycete Phytophthora capsici is one of the most devastating pathogens to pepper production worldwide, causing more than $100 million in losses annually. Developing cultivars resistant to P. capsici is challenging because of the many physiological races that exist and new races that are continuously evolving. This problem is confounded by the lack of a universal system of race characterization. As a basis to develop a global anticipatory breeding program, New Mexico recombinant inbred lines (NMRILs) functioned as a host differential for Phytophthora root rot to characterize the race structure of P. capsici populations in Taiwan. Using the NMRILs, 24 new races were identified, illustrating the utility and usefulness of the NMRILs for anticipatory breeding. Virulence of P. capsici was observed to be geographically specific and in two virulence clusters. Interestingly, all but two isolates collected in 2016 were the A2 mating type, which is a shift from the predominantly A1 mating type isolates collected prior to 2008. The NMRILs host differential provides an approach for scientists to work together on a global scale when breeding for resistance as well as on a local level for regional gene deployment. Additionally, we propose that the current race numbering system, which has no biological meaning, be supplemented with the virulence phenotype, based on the susceptible NMRILs to a given isolate. This work provides insights into the population dynamics of P. capsici and interactions within the highly complex Capsicum−Phytophthora pathosystem, and offers a basis for similar research in other crops.

scholarly journals New Sources of Resistance in Winter Squash (Cucurbita moschata) to Phytophthora Crown Rot and Their Relationship to Cultivated Squash

2021 ◽  
Author(s):  
Chandrasekar S. Kousik ◽  
Gregory Vogel ◽  
Jennifer L. Ikerd ◽  
Mihir K. Mandal ◽  
Michael Mazourek ◽  
...  
Keyword(s):  
South Carolina ◽  
Root Rot ◽  
Rating Scale ◽  
Phytophthora Capsici ◽  
Crown Rot ◽  
Human Consumption ◽  
Cucurbita Moschata ◽  
Sources Of Resistance ◽  
Plant Introductions ◽  
Crown And Root Rot

Butternut squash (Cucurbita moschata) is an important vegetable crop grown and consumed in most states in the USA. Cucurbita moschata lines and interspecific hybrids between Cucurbita species are also used as rootstocks for grafting watermelon and melon. However, currently most commercially available C. moschata squash varieties are highly susceptible to crown and root rot caused by the oomycete pathogen Phytophthora capsici, especially in the southeastern USA. All available plant introductions (PIs) of C. moschata (319 PIs) were evaluated for resistance to crown rot. Four-week-old plants were inoculated with 104 zoospores from a local South Carolina (SC) isolate of P. capsici. Plants were rated for disease severity three weeks after inoculation using a 0-5 rating scale (0=No symptoms and 5=Plant dead). The majority (87%) of the C. moschata PIs were highly susceptible to crown rot in the first evaluation and were rated as 5. Reevaluation of the promising PIs identified several potential new sources of resistance (e.g. Grif 935, PI 442272, PI 442264, PI 512142, PI 438724, PI 438778, PI 442280). Variability in resistance reaction among plants within a PI was also observed, and not all plants exhibited resistance. Further evaluation of S1 generation from the most resistant plants (rated ≤1) demonstrated that highly resistant plants could be selected from these PIs to develop lines for use in breeding programs. These new sources of resistance can be utilized for developing new crown and root rot resistant rootstocks for watermelon grafting and for developing resistant varieties for human consumption.

scholarly journals Phytophthora Root Rot Resistance and Its Correlation with Fruit Rot Resistance in Capsicum annuum

HortScience ◽  
2020 ◽  
Vol 55 (12) ◽  
pp. 1931-1937
Author(s):  
Rachel P. Naegele ◽  
Mary K. Hausbeck
Keyword(s):  
Broad Spectrum ◽  
Root Rot ◽  
Partial Resistance ◽  
Phytophthora Capsici ◽  
Fruit Rot ◽  
Multiple Sources ◽  
Sources Of Resistance ◽  
Phytophthora Root Rot ◽  
Foliar Blight ◽  
Moderate Resistance

Phytophthora capsici causes root and fruit rot and foliar blight of pepper. Multiple sources of resistance to Phytophthora root rot have previously been identified, but most display only partial resistance. One source, CM334, has broad spectrum root rot resistance to multiple pathogen isolates but has only low to moderate fruit rot resistance. This study evaluated previously identified pepper lines for resistance to two P. capsici isolates, OP97 and 12889, and compared root rot resistance to fruit rot resistance and genetic structure. CM334 was confirmed as a broad spectrum resistance genotype, whereas all other sources of resistance evaluated were susceptible to infection by one or both isolates evaluated. Although not completely resistant, PI 566811 displayed moderate resistance to fruit and root rot to both P. capsici isolates. Fruit rot resistance had a significant but small to moderate positive correlation (r = 0.26–0.63) with root rot resistance depending on the isolate and length of exposure. Pepper accessions with resistance to Phytophthora root and fruit rot belonging to different genetic subpopulations were identified and could serve as candidates for partial-resistance loci to incorporate into pepper breeding programs.

Sign in / Sign up

Export Citation Format

Share Document