scholarly journals Field Evaluation of Potato Resistance Against Phytophthora Infestans under Natural Infection Pressure

2017 ◽  
Vol 76 (1) ◽  
pp. 25-28
Author(s):  
Jarosław Plich ◽  
Beata Tatarowska

Abstract Although development of potato cultivars resistant to late blight has long been one of the primary goals of potato breeding programs, several different methods of field resistance evaluation have been used by potato breeders. Recently, within the EucaBlight network (www.euroblight.net), common methods of late blight evaluation have been agreed on, and these methods are currently highly recommended for use by all those interested in evaluating the resistance of the potato to late blight. Here, we describe a method of evaluating potato resistance in field conditions routinely used at Młochów Research Center, which is compliant with recommendations of the EucaBlight protocol.

2013 ◽  
Vol 42 (1-2) ◽  
pp. 95-104
Author(s):  
Elżbieta Horodecka

The purpose of the investigations carried out in 1983-1985 was to assess the usefulness of natural and artificial infections under field conditions for evaluating tomato resistance to late blight in Poland. It was found, that the degree of natural infection by this fungus was a better indicator of tomato resistance than the degree of artificial infection obtained under field conditions.


2021 ◽  
Author(s):  
Xiumei Luo ◽  
Tingting Tian ◽  
Maxime Bonnave ◽  
Xue Tan ◽  
Xiaoqing Huang ◽  
...  

Reactive oxygen species (ROS) are critical for the growth, development, proliferation, and pathogenicity of microbial pathogens; however, excessive levels of ROS are toxic. Little is known regarding the signaling cascades in response to ROS stress in oomycetes such as Phytophthora infestans, the causal agent of potato late blight. Here, P. infestans was used as a model system to investigate the mechanism underlying the response to ROS stress in oomycete pathogens. Results showed severe defects in sporangium germination, mycelial growth, appressorium formation, and virulence of P. infestans in response to H2O2 stress. Importantly, these phenotypes mimic those of P. infestans treated with rapamycin, the inhibitor of target of rapamycin (TOR, 1-phosphatidylinositol-3-kinase). Strong synergism occurred when P. infestans was treated with a combination of H2O2 and rapamycin, suggesting that a crosstalk exists between ROS stress and the TOR signaling pathway. Comprehensive analysis of transcriptome, proteome and phosphorylation omics showed that H2O2 stress significantly induced the operation of the TOR-mediated autophagy pathway. Monodansylcadaverine (MDC) staining showed that in the presence of H2O2 and rapamycin, the autophagosome level increased in a dosage-dependent manner. Furthermore, transgenic potatoes containing double-stranded RNA of PiTOR (TOR in P. infestans) displayed high resistance to P. infestans. Taken together, TOR is involved in the ROS response and is a potential target for control of oomycete diseases, as host-mediated silencing of PiTOR enhances potato resistance to late blight.


2008 ◽  
Vol 34 (1) ◽  
pp. 86-87 ◽  
Author(s):  
Bernardo A. Halfeld-Vieira ◽  
Reginaldo S. Romeiro ◽  
Ann Mounteer ◽  
Eduardo S.G. Mizubuti

The capacity of two bacteria isolated from the tomato phylloplane to control late blight (Phytophthora infestans) was investigated in the field, and compared against the effectiveness of spraying with the fungicide chlorothalonil (1.5 g a.i. L-1) or water (control). A 55% reduction in late blight intensity was observed in the leaves of the middle of the plant and 62% in those of the upper leaves when using the antagonist UFV-STB 6 (Novosphingobium capsulatum) as compared to the control. Isolate UFV-IEA 6 (Bacillus cereus) was able to reduce disease intensity by 55%, but only in the upper leaves of the tomato plants. Treatment with isolate UFV-STB 6 also led to a significant reduction in the percentage of fruits with late blight symptoms. The results demonstrate the potential of these two bacteria in controlling this disease.


1959 ◽  
Vol 37 (1) ◽  
pp. 41-49 ◽  
Author(s):  
K. M. Graham ◽  
J. S. Niederhauser ◽  
Leopoldo Servin

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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