scholarly journals Curvularia Lunata as New Causal Pathogen of Tomato Early Blight Disease in Egypt

Author(s):  
Heba-Alla S. AbdElatah ◽  
Nashwa M.A. Sallam ◽  
Mohamed S. Mohamed ◽  
Hadeel M. M. Khalil Bagy

Abstract Tomato plants displaying early blight symptoms were collected from different localities in the provinces of Assiut and Sohag, Egypt. The causal pathogens were isolated on potato dextrose agar plates. Pathogenicity tests with 48 isolates were carried out under greenhouse conditions on tomato cultivar (CV 844). All tested isolates caused symptoms of early blight disease with different degrees. The highest disease severity on tomato plants was found after inoculation with isolate No. 6 followed by isolates No. 20 and No. 31. The most pathogenic isolates were identified by sequence analysis using ITS1 and ITS4 primers. The analysis of the amplified sequences from fungal isolates No. 6, 20 and 31 displayed 99 - 100% nucleotide identity with Alternaria solani, Curvularia lunata and A. alternata, respectively. To our knowledge, this is the first report of Curvularia lunata as one of the causal pathogens of early blight disease of tomato plants in Egypt.

2019 ◽  
Vol 72 (1) ◽  
pp. 69-76 ◽  
Author(s):  
Jesús S. Hernández-Ochoa ◽  
Laura N. Levin ◽  
Carlos E. Hernández-Luna ◽  
Juan Francisco Contreras-Cordero ◽  
Guillermo Niño-Medina ◽  
...  

2021 ◽  
Vol 10 (1) ◽  
pp. 094-104
Author(s):  
Ahmed S. Abdel–Aty ◽  
Elsayed A.M. Abdallah ◽  
Ezzat A. kaduos ◽  
Mohamed R. A. Gad

Fungicidal activity of nine selected conventional fungicides, identified five plant oils and their combined effect against A. solani, the causal pathogen of early blight on tomato. GC-MS analysis of the tested oils indicated that terpene hydrocarbons (97%) with cinnamaldehyde as the major compound; sulfur compounds; fatty acids and organo-sulfur-containing compounds were the main components in cinnamon, garlic, mustard and onion oils, respectively. In vitro, Speedcide® (difenoconazole) and Cabrioduo® (Dimethomorph + Pyraclostrobin) were the most effective against the A. solani fungus with EC50 values of 94.6 and 88.6 ppm respectively. Toledo® (Tebuconzole) achieved EC50 value of 631.2 ppm. Roxyl-M® was significantly more effective than Roxyl–plus® or Remik®. Speedcide® alone or mixed with mandipropamid or azoxystrobin in Revus-Top® or Cruze® were the lowest effective in vitro. Garlic and mustard oils were more effective in liquid media than solid one. Cinnamon, onion, garlic and bitter almond oils caused moderate fungi-toxicity against early blight pathogen and could be implemented in the IPM program. Lower EC50 values were obtained in case of combinations of fungicides with oils than separate treatments. Effect of the active conventional fungicides and plant oils on disease indices, relative disease control, chlorophyll content, sugar contents and poly phenol oxidase in tomato plants was also studied.


Author(s):  
Heba-Alla S. AbdElfatah ◽  
Nashwa M. A. Sallam ◽  
Mohamed S. Mohamed ◽  
Hadeel M. M. Khalil Bagy

2021 ◽  
Vol 6 (1) ◽  
pp. 91-98
Author(s):  
A. Bello ◽  
◽  
J. B. Ameh ◽  
D. A. Machido ◽  
A. I. Mohammed-Dabo

Laccases are oxidases with broad substrate specificity and ability to oxidize various phenolic and non-phenolic compounds. This study was carried out to isolate and characterizes laccase producing fungi from environment samples. Soil and decaying wood samples were collected from different locations within Ahmadu Bello University, Zaria Main campus. Suspensions of the samples (1 g in 10 mL sterile distilled water) were serially diluted, inoculated onto Potato Dextrose Agar (PDA) containing 0.01% Chloramphenicol and incubated for 7 days at 30oC.The fungal isolates were characterized macroscopically and microscopically with the aid of an atlas. The identified fungal isolates were screened for laccase production by inoculating onto PDA containing 0.02% Guaiacol, 1mM ABTS (2 2’-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) and 0.5% Tannic acid as indicator compounds and incubated at 250C for 7 days. The laccase producing isolates were confirmed molecularly by ITS rDNA sequence analysis using the FASTA algorithm with the Fungus database from the European Bioinformatics Institute (EBI).A total of 25 fungal species (11 from soil and 14 from decaying wood samples) were isolated. Two isolates from the soil origin identified as Curvularia lunata SSI7 (Accession No. QIE06317.1) and Fusarium clade VII SSI3 (Accession No. GQ505677) were found to produce laccase where Curvularia lunata SSI7 was able to oxidize all the indicator compounds used for the screening. Fusarium clade VII SSI3 was able to oxidize only 0.5% Tannic acid. Laccase producing Curvularia lunata and Fusarium clade VII were isolated from soil samples collected from ABU Zaria Main Campus. Keywords: laccase, fungi, soil, decaying wood


2012 ◽  
Vol 48 (No. 2) ◽  
pp. 74-79 ◽  
Author(s):  
S.M.A. Nashwa ◽  
K.A.M. Abo-Elyousr

The antimicrobial activity of six plant extracts from Ocimum basilicum (Sweat Basil), Azadirachta indica (Neem), Eucalyptus chamadulonsis (Eucalyptus), Datura stramonium (Jimsonweed), Nerium oleander (Oleander), and Allium sativum (Garlic) was tested for controlling Alternaria solani in vitro and in vivo. In in vitro study the leaf extracts of D. stramonium, A. indica, and A. sativum at 5% concentration caused the highest reduction of mycelial growth of A. solani (44.4, 43.3 and 42.2%, respectively), while O. basilicum at 1% and 5% concentration and N. oleander at 5% concentration caused the lowest inhibition of mycelial growth of the pathogen. In greenhouse experiments the highest reduction of disease severity was achieved by the extracts of A. sativum at 5% concentration and D. stramonium at 1% and 5% concentration. The greatest reduction of disease severity was achieved by A. sativum at 5% concentration and the smallest reduction was obtained when tomato plants were treated with O. basilicum at 1% and 5% concentration (46.1 and 45.2 %, respectively). D. stramonium and A. sativum at 5% concentration increased the fruit yield by 76.2% and 66.7% compared to the infected control. All treatments with plant extracts significantly reduced the early blight disease as well as increased the yield of tomato compared to the infected control under field conditions.


Plant Disease ◽  
2000 ◽  
Vol 84 (10) ◽  
pp. 1152-1152
Author(s):  
S. K. Kim ◽  
S. S. Hong ◽  
K. W. Kim ◽  
E. W. Park

A wilt disease occurred on greenhouse-grown eggplants (Solanum melongena L.) at Hanam and Yeojoo, Korea, in 1997. Lower leaves on the 2-month-old wilted eggplants exhibited gradual yellowing, interveinal necrosis, and marginal crinkling and dropped prematurely. Vascular tissues of diseased stems were discolored and turned black. Vertical sections of the stems revealed that the pith had been colonized by the fungus. The disease progressed from lower parts of the plants upward. Incidence of diseased eggplants in greenhouses was 5% on 23 May 1997. Although the incidence increased to 10% on 13 June, it remained constant through early July. Fungal isolates from discolored vascular tissues were initially whitish to cream color on potato-dextrose agar, which turned black due to the formation of microsclerotia. The fungus also produced abundant verticillate conidiophores with phialides and conidia. Based on these cultural and morphological characteristics, the fungus was identified as Verticillium dahliae Klebahn. Pathogenicity tests by root cutting, root dipping, or soil drenching resulted in similar symptoms observed in the naturally infected eggplants. Symptoms were first observed on lower leaves of each eggplant 3 weeks after inoculation. Isolation from symptomatic leaves of the inoculated eggplants yielded V. dahliae. This is the first report of occurrence of Verticillium wilt of eggplant in Korea.


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