Articles
Morphological characteristics and pathogenicity of Alternaria and Stemphylium isolates on tomato in vitro
Article number
1378_43
Pages
325 – 332
Language
English
Abstract
Tomato (Solanum lycopersicum L.) is the most commercialized vegetable in Latvia, representing 43.9% (2020) of the total export value of fresh vegetables.
The tomato plant is susceptible to several diseases caused by fungal pathogens.
Until now, no research on tomato diseases has been carried out in Latvia.
Early blight (caused by Alternaria spp.) and grey leaf spot (caused by Stemphylium spp.) are commonly observed diseases of tomato.
These diseases may affect foliage, stems, and fruits, and cause significant production and economic losses.
Symptoms of diseases are similar, and complex infection is also possible.
The aim of the research is to compare morphological characteristics of the Alternaria and Stemphylium isolates and determine their pathogenicity on tomato.
Samples of leaves and fruits with characteristic symptoms of early blight and grey leaf spot were collected during the 2021 crop season.
Pathogens were isolated as single spore on potato dextrose agar medium (PDA). After two weeks, the colour, type of growth, structure of mycelium, and the presence of spores were evaluated.
For pathogenicity testing, mycelia plugs (5 mm in diameter for each isolate) were placed in the centre of detached tomato leaves and on mature green and red ripe tomato fruits; the pathogenicity was evaluated after seven days.
Morphological characteristics of the Alternaria spp. and Stemphylium spp. isolates varied, and further research is required to identify the species.
Pathogenicity differed depending on the genera, isolates, and organs of hosts.
The tomato plant is susceptible to several diseases caused by fungal pathogens.
Until now, no research on tomato diseases has been carried out in Latvia.
Early blight (caused by Alternaria spp.) and grey leaf spot (caused by Stemphylium spp.) are commonly observed diseases of tomato.
These diseases may affect foliage, stems, and fruits, and cause significant production and economic losses.
Symptoms of diseases are similar, and complex infection is also possible.
The aim of the research is to compare morphological characteristics of the Alternaria and Stemphylium isolates and determine their pathogenicity on tomato.
Samples of leaves and fruits with characteristic symptoms of early blight and grey leaf spot were collected during the 2021 crop season.
Pathogens were isolated as single spore on potato dextrose agar medium (PDA). After two weeks, the colour, type of growth, structure of mycelium, and the presence of spores were evaluated.
For pathogenicity testing, mycelia plugs (5 mm in diameter for each isolate) were placed in the centre of detached tomato leaves and on mature green and red ripe tomato fruits; the pathogenicity was evaluated after seven days.
Morphological characteristics of the Alternaria spp. and Stemphylium spp. isolates varied, and further research is required to identify the species.
Pathogenicity differed depending on the genera, isolates, and organs of hosts.
Authors
L. Dučkena, G. Bimšteine
Keywords
Solanum lycopersicum L., early blight, grey leaf spot, morphological characteristics
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