scholarly journals Phytophthora spp.: Economic Plant Threats in Egypt

2021 ◽  
Author(s):  
Waleed Mohamed Hussain Abdulkhair
Keyword(s):  
Late Blight ◽  
Integrated Management ◽  
Potato Crop ◽  
Control Plant ◽  
Phytophthora Nicotianae ◽  
Management Approach ◽  
Economic Plant ◽  
Phytophthora Spp ◽  
Rot Disease ◽  
Blight Disease

The potato crop is exposed to infection with many fungal diseases including late blight, caused by Phytophthora infestans. The control of late blight disease requires an integrated management approach represented in cultivation control, plant resistance, and fungicide control. The citrus plants are infected by Phytophthora nicotianae that is causing root rot disease in Egypt. Three species of Phytophthora responsible for infection of citrus plants; P. nicotianae, P. citrophthora, and P. palmivora. Other pathogens associate P. nicotianae and form complexes or coinfection that release different diseases for citrus plants such as gummosis, Phytophthora–Diaprepes complex (PDC), and Huanglongbing syndrome (HLBS).

scholarly journals Eco-friendly management of late blight of potato– A review

2017 ◽  
Vol 9 (2) ◽  
pp. 821-835
Author(s):  
Shailbala Shailbala ◽  
Amarendra Kumar
Keyword(s):  
Late Blight ◽  
Mycorrhizal Fungi ◽  
Cultural Practices ◽  
Potato Crop ◽  
Rapid Development ◽  
Management Strategies ◽  
Irish Famine ◽  
Forecasting System ◽  
Blight Disease ◽  
Late Blight Of Potato

 Late blight of potato caused by fungus Phytophthora infestans responsible for Irish famine in the year 1845, is one of the most dramatic episode caused by plant pathogen in human history. One million people died due to famine in Ireland. So eco-friendly management of potato late blight disease is a necessary goal to be accomplished.During last many years, management strategies solely relied upon the application of fungicides due to rapid development of late blight epidemics. However, indiscriminate use of fungicide posesses a serious threat to the environment and human health. It is also responsible for built up of resistance in the pathogen and have adverse effect on beneficial organisms such as nitrogen fixers, resident antagonism and mycorrhizal fungi. So to minimize the fungicide use, eco-friendly means for late blight management are required on a priority basis. In recent years, significant changes in isolates of late blight fungus have been recorded including changes in aggressiveness to the crop also. Since, late blight is a community disease so, effective eco-friendly management must be adopted by the all producers, farmers, gardeners and growers with the help of government agencies, extension specialist and crop consultants etc. The strategy to control late blight is the prevention of establishment of Phytophthorainfestans in potato crop. In this context, disease management by cultural practices is the first line of defense while forecasting system, physiological strategies, biological control, host plant resistance and bio-technological approach are essential for efficient, effective and eco-friendly management of late blight of potato.

scholarly journals First signs of late blight resistance in traditional native potatoes of Pasco—Peru, a preliminary assay

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Edith Zevallos ◽  
Josue Inga ◽  
Fernando Alvarez ◽  
Karina Marmolejo ◽  
Rocio Paitan ◽  
...  
Keyword(s):  
Late Blight ◽  
Potato Crop ◽  
Natural Infection ◽  
Late Blight Resistance ◽  
Relative Effect ◽  
Subsistence Farmers ◽  
Pests And Diseases ◽  
Broad Variety ◽  
Blight Disease ◽  
Moderately Resistant

Abstract Background The native Andean potatoes, despite their low yield, have a large diversity that is conserved by subsistence farmers in Peru, due to their culinary characteristics and other qualities. However, this diversity is threatened by the impacts of climate change, which would directly affect the food security of these people, and eventually ours. Among its qualities of resistance to pests and diseases, there could be a genetic source of resistance to late blight, one of the most damaging diseases of the potato crop in the world. In this assay, 103 native landraces collected from local farmers in the Pasco region of Peru were subjected to natural infection conditions with Phytophthora infestans to identify potential resistant landraces within them. Results The 103 landraces assessed showed a broad variety of responses and were classified as “resistant” (22%), “moderately resistant” (57%), and “susceptible landraces” (21%). A relative effect of the disease in the yield is also shown, which is already low for commercial intentions. Conclusion Within this representative sample of the native potato diversity of the Pasco region, at least 23 local varieties grown by subsistence farmers have resistance qualities against eventual late blight disease.

scholarly journals Genotype reaction of Solanum tuberosum, andigena and phureja groups to late blight (Phytophthora infestans Mont. De Bary)

2019 ◽  
Vol 36 (E) ◽  
pp. 138-157
Author(s):  
Jennyfer Moncayo ◽  
Roberth Delgado ◽  
Carlos Marcillo ◽  
Claudia Salazar ◽  
Carlos Betancourth
Keyword(s):  
Solanum Tuberosum ◽  
Late Blight ◽  
Phytophthora Infestans ◽  
Potato Crop ◽  
Block Design ◽  
Food Product ◽  
Randomized Complete Block Design ◽  
Late Blight Disease ◽  
Disease Effect ◽  
Blight Disease

Potato crop is the fourth main food product in the world, but is affected by Phytophthora infestans, the late blight disease causal agent. This research was carried out in a town of Pasto high plateau, South of Colombia. In order to evaluate the reaction of different genotypes of creole potato (Solanum tuberosum groups Phureja and Andigena) with regard the disease. A Randomized Complete Block design was established with three repetitions, where 30 genotypes were distributed and three plants were evaluated per repetition during two crop cycles in natural exposure to the pathogen. To assess the disease effect on production, the same genotypes were maintained with chemical control in an adjacent batch. Genotypes classified as tolerant are Chaucha Manzana, Cachuda, Criolla Colombia, Malvaseña, Andina and Criolla, during the first cycle with performance values ​​between 23 to 26t.ha-1 and during the second to Calavera Negra, Chaucha Paisa, Ratona, Criolla Galeras, Ratona Roja, Tornilla Roja and Aguacata with performance values ​​between 23 to 28t.ha-1. The graphic severity scale allowed genotypes to be categorized as susceptible and highly susceptible. The results indicate that for the prevalent pathogen race in this study area, there are no resistance sources within the studied collection. However, genotypes such as Criolla Colombia and Andina showed a better performance in terms of yield.

scholarly journals A Foliar Blight and Tuber Rot of Potato Caused by Phytophthora nicotianae: New Occurrences and Characterization of Isolates

Plant Disease ◽  
2008 ◽  
Vol 92 (4) ◽  
pp. 492-503 ◽  
Author(s):  
Raymond J. Taylor ◽  
Julie S. Pasche ◽  
Courtney A. Gallup ◽  
H. David Shew ◽  
Neil C. Gudmestad
Keyword(s):  
Late Blight ◽  
Natural Infection ◽  
Phytophthora Nicotianae ◽  
Pink Rot ◽  
Foliar Blight ◽  
Phytophthora Spp ◽  
Commercial Potato ◽  
Potato Foliage ◽  
First Time

Phytophthora spp. are pathogenic to many plant species worldwide, and late blight, caused by Phytophthora infestans, and pink rot, caused by P. erythroseptica, are two important diseases of potato. Another Phytophthora sp., P. nicotianae, was recovered from pink-rot-symptomatic tubers collected from commercial fields in Nebraska, Florida, and Missouri in 2005, 2006, and 2007, respectively. P. nicotianae also was recovered from foliage obtained from commercial potato fields in Nebraska and Texas exhibiting symptoms very similar to those of late blight. Isolates of P. cactorum also were recovered from foliar infections in a commercial potato field in Minnesota in 2005. Natural infection of potato foliage by P. cactorum and infection of wounded potato tuber tissue via inoculation with zoospores of P. capsici are reported here for the first time. Isolates of P. nicotianae, regardless of origin, were primarily of the A1 mating type. All isolates of P. nicotianae and P. cactorum were sensitive to the fungicide mefenoxam. Optimum growth of P. nicotianae, P. erythroseptica, and P. cactorum in vitro occurred at 25°C; however, only P. nicotianae sustained growth at 35°C. Regardless of the tissue of origin, all isolates of P. nicotianae and P. cactorum were capable of infecting potato tubers and leaves. However, isolates of P. nicotianae were less aggressive than P. erythroseptica isolates only when tubers were not wounded prior to inoculation. Pink rot incidence varied significantly among potato cultivars following inoculation of nonwounded tubers with zoospores of P. nicotianae, ranging from 51% in Red Norland to 19% in Atlantic. Phytophthora spp. also differed significantly in their ability to infect potato leaves. Highest infection frequencies were obtained with P. infestans and levels of infection varied significantly among P. nicotianae isolates. The rate of foliar lesion expansion was similar among isolates of P. nicotianae and P. infestans. Whereas P. infestans infections yielded profuse sporulation, no sporulation was observed with foliar infections of P. nicotianae.

scholarly journals Fitness Evaluation of Phytophthora infestans Isolates Collected from Punjab, Pakistan During 2017-18

2019 ◽  
Vol 39 (04) ◽  
Author(s):  
Waqas Raza ◽  
Muhammad Usman Ghazanfar ◽  
Muhammad Imran Hamid
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Potato Crop ◽  
Lesion Size ◽  
Management Approach ◽  
Fitness Evaluation ◽  
Pathogen Fitness ◽  
Detached Leaves ◽  
Fitness Parameters ◽  
Experimental Findings

Potato late blight (Phytophthora infestans) is an important disease causing severe damage in potato crop worldwide. Seventy seven isolates of P. infestans selected on the basis of aggressiveness were characterized for pathogen fitness test based on their lesion size, latent incubation period and sporulation capacity after their inoculation onto detached leaves of potato. The results showed that large variations in pathogen fitness were present among isolates for each regional P. infestans population studied. Those isolates selected during 2017-18 exhibited 85% and 74% successful pathogen fitness behavior respectively. Those isolates which had higher composite fitness index values were observed higher lesion size and spore count and same trend of pathogen fitness parameters was observed with respect to their districts during both the years.This is the first inclusive study to determine pathogen fitness of isolates in Pakistan. The experimental findings indicated that population of P. infestans in the Punjab province comprises diverse isolates with low to high fitness potential. A future challenge planned to combine our accumulated knowledge with that from other scientific fields to develop a disease management approach for late blight.

scholarly journals Genotype reaction of Solanum tuberosum, andigena and phureja groups to late blight (Phytophthora infestans Mont. De Bary)

2019 ◽  
Vol 36 (E) ◽  
pp. 138-157
Author(s):  
Jennyfer Moncayo ◽  
Roberth Delgado ◽  
Carlos Marcillo ◽  
Claudia Salazar ◽  
Carlos Betancourth
Keyword(s):  
Solanum Tuberosum ◽  
Late Blight ◽  
Phytophthora Infestans ◽  
Potato Crop ◽  
Block Design ◽  
Food Product ◽  
Randomized Complete Block Design ◽  
Late Blight Disease ◽  
Disease Effect ◽  
Blight Disease

Potato crop is the fourth main food product in the world, but is affected by Phytophthora infestans, the late blight disease causal agent. This research was carried out in a town of Pasto high plateau, South of Colombia. In order to evaluate the reaction of different genotypes of creole potato (Solanum tuberosum groups Phureja and Andigena) with regard the disease. A Randomized Complete Block design was established with three repetitions, where 30 genotypes were distributed and three plants were evaluated per repetition during two crop cycles in natural exposure to the pathogen. To assess the disease effect on production, the same genotypes were maintained with chemical control in an adjacent batch. Genotypes classified as tolerant are Chaucha Manzana, Cachuda, Criolla Colombia, Malvaseña, Andina and Criolla, during the first cycle with performance values ​​between 23 to 26t.ha-1 and during the second to Calavera Negra, Chaucha Paisa, Ratona, Criolla Galeras, Ratona Roja, Tornilla Roja and Aguacata with performance values ​​between 23 to 28t.ha-1. The graphic severity scale allowed genotypes to be categorized as susceptible and highly susceptible. The results indicate that for the prevalent pathogen race in this study area, there are no resistance sources within the studied collection. However, genotypes such as Criolla Colombia and Andina showed a better performance in terms of yield.

Principles of the Human Integrated Management Approach (HIMA): Towards Sustainable Development

2012 ◽  
Author(s):  
Walid Saleh ◽  
Mukhtar Hashemi ◽  
Sana Hawamdeh
Keyword(s):  
Sustainable Development ◽  
Integrated Management ◽  
Management Approach

scholarly journals Protection of Citrus Rootstocks Against Phytophthora spp. with a Hypovirulent Isolate of Phytophthora nicotianae

2007 ◽  
Vol 97 (8) ◽  
pp. 958-963 ◽  
Author(s):  
G. C. Colburn ◽  
J. H. Graham
Keyword(s):  
Poncirus Trifoliata ◽  
Phytophthora Nicotianae ◽  
Root Weight ◽  
Post Inoculation ◽  
Phytophthora Root Rot ◽  
Phytophthora Spp ◽  
Naturally Occurring ◽  
Fibrous Roots ◽  
Cleopatra Mandarin ◽  
Swingle Citrumelo

Phytophthora root rot of citrus in Florida is caused by Phytophthora nicotianae and P. palmivora. A naturally occurring isolate of P. nicotianae (Pn117) was characterized as hypovirulent on citrus roots. Pn117 infected and colonized fibrous roots, but caused significantly less disease than the virulent isolates P. nicotianae Pn198 and P. palmivora Pp99. Coincident inoculation of rootstock seedlings of Cleopatra mandarin (Citrus reticulata) or Swingle citrumelo (C. paradisi × Poncirus trifoliata) with the hypovirulent Pn117 and the virulent isolates Pn198 and Pp99 did not reduce the severity of disease caused by the virulent Phytophthora spp. When either rootstock was inoculated with the hypovirulent Pn117 for 3 days prior to inoculation with virulent isolates, preinoculated seedlings had significantly less disease and greater root weight compared with seedlings inoculated with the virulent isolates alone. Recovery of the different colony types of Phytophthora spp. from roots of sweet orange (C. sinensis) or Swingle citrumelo was evaluated on semiselective medium after sequential inoculations with the hypovirulent Pn117 and virulent Pp99. Pn117 was isolated from roots at the same level as the Pp99 at 3 days post inoculation. Preinoculation of Pn117 for 3 days followed by inoculation with Pp99 resulted in greater recovery of the hypovirulent isolate and lower recovery of the virulent compared with coincident inoculation.

scholarly journals In Vitro and In Vivo Antifungal Activity of Sorbicillinoids Produced by Trichoderma longibrachiatum

2021 ◽  
Vol 7 (6) ◽  
pp. 428
Author(s):  
Men Thi Ngo ◽  
Minh Van Nguyen ◽  
Jae Woo Han ◽  
Myung Soo Park ◽  
Hun Kim ◽  
...  
Keyword(s):  
Late Blight ◽  
Culture Filtrate ◽  
Fungal Pathogens ◽  
Gray Mold ◽  
Trichoderma Longibrachiatum ◽  
Chemical Structures ◽  
Natural Agents ◽  
Blight Disease

In the search for antifungal agents from marine resources, we recently found that the culture filtrate of Trichoderma longibrachiatum SFC100166 effectively suppressed the development of tomato gray mold, rice blast, and tomato late blight. The culture filtrate was then successively extracted with ethyl acetate and n-butanol to identify the fungicidal metabolites. Consequently, a new compound, spirosorbicillinol D (1), and a new natural compound, 2′,3′-dihydro-epoxysorbicillinol (2), together with 11 known compounds (3–13), were obtained from the solvent extracts. The chemical structures were determined by spectroscopic analyses and comparison with literature values. The results of the in vitro antifungal assay showed that of the tested fungal pathogens, Phytophthora infestans was the fungus most sensitive to the isolated compounds, with MIC values ranging from 6.3 to 400 µg/mL, except for trichotetronine (9) and trichodimerol (10). When tomato plants were treated with the representative compounds (4, 6, 7, and 11), bisvertinolone (6) strongly reduced the development of tomato late blight disease compared to the untreated control. Taken together, our results revealed that the culture filtrate of T. longibrachiatum SFC100166 and its metabolites could be useful sources for the development of new natural agents to control late blight caused by P. infestans.

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