Diversity and geographic distribution of fungal strains infecting field-grown common bean (Phaseolus vulgaris L.) in Tunisia
A collection of 103 fungal strains was established from infected common bean plants ( Phaseolus vulgaris L.) field-grown in three geographic regions from Tunisia and known for their long history in bean culture; Boucharray, Chatt-Mariem, and Metline. The fungal strain collection was established from...
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Published in | European journal of plant pathology Vol. 153; no. 3; pp. 947 - 955 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Dordrecht
Springer Netherlands
01.03.2019
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | A collection of 103 fungal strains was established from infected common bean plants (
Phaseolus vulgaris
L.) field-grown in three geographic regions from Tunisia and known for their long history in bean culture; Boucharray, Chatt-Mariem, and Metline. The fungal strain collection was established from common bean root and aerial parts. The pathogenicity test carried out on germinated seedlings showed that among the fungal collection, 41% of fungal strains were assigned to be highly pathogenic. In fact, serious cases of seedling damping-off, as well as a significant reduction in root and shoot biomass in cv. Coco blanc were noticed (up to 90% biomass reduction) considering fungal strains from the three prospected localities. The identification of fungal isolates belonging to this high pathogenicity class, based on the internal transcribed spacer region (ITS), showed a wide generic and specific diversity among common bean pathogenic fungi in Tunisia.
Fusarium
spp. strains were dominant and represented 67% of the characterized fungal collection. Fungal genera including
Alternaria
(22%),
Rhizoctonia
(4%),
Ascomycota
(4%),
Macrophomina
(10%) and
Phoma
(4%) were also reported. The highest richness levels were found in the Chatt-Mariem and Boucharray regions, showing the highest generic and interspecific diversity. In this work, we revealed also a variability in the abundance and geographic distribution of fungal species between the three prospected regions. Fungal strains infecting common bean in Metline were represented exclusively by
Fusarium oxysporum
. However, the genus
Fusarium
represented about 66% of fungal strains recovered from Boucharray, and only 20% from Chatt-Mariem. The genus
Alternaria
represented 11% and 40% of total fungal isolates in Boucharray and Chatt-Mariem, respectively, and was isolated only from the foliar parts of diseased common bean plants. The present work represents an important database that should be considered for surveying common bean fungal diseases. |
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ISSN: | 0929-1873 1573-8469 |
DOI: | 10.1007/s10658-018-01612-y |