Verticillium wilt of Ailanthus altissima in Italy caused by V. dahliae: new outbreaks from Tuscany
Verticillium spp., including V. nonalfalfae and V. dahliae, are known vascular wilt pathogens of the invasive Ailanthus altissima (tree-of-heaven) in the United States and in Europe. Herein we provide evidence of the presence of a previously unreported wilt disease of A. altissima in Tuscany (Centra...
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| Format: | Article |
| Language: | English |
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Italian Society of Silviculture and Forest Ecology (SISEF)
2020-06-01
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| Series: | iForest - Biogeosciences and Forestry |
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| Online Access: | https://iforest.sisef.org/contents/?id=ifor3238-013 |
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| author | Pisuttu C Marchica A Bernardi R Calzone A Cotrozzi L Nali C Pellegrini E Lorenzini G |
| author_facet | Pisuttu C Marchica A Bernardi R Calzone A Cotrozzi L Nali C Pellegrini E Lorenzini G |
| author_sort | Pisuttu C |
| collection | DOAJ |
| description | Verticillium spp., including V. nonalfalfae and V. dahliae, are known vascular wilt pathogens of the invasive Ailanthus altissima (tree-of-heaven) in the United States and in Europe. Herein we provide evidence of the presence of a previously unreported wilt disease of A. altissima in Tuscany (Central Italy). Several isolates were collected from two locations and identified as V. dahliae, based on microscopical features of conidiophores, conidia and microsclerotia. Genomic DNA was extracted from the mycelium, the ITS region was amplified and the sequence was deposited in GenBank as VdGL16 (accession no. MK474459). BLASTn analysis showed 100% similarity with V. dahliae. To confirm pathogenicity of VdGL16, inoculations of Ailanthus seedlings were performed with the root dipping technique whereas mature trees were stem-inoculated. All inoculated seedlings exhibited wilt symptoms after 20 days, while mature Ailanthus trees showed wilting and dieback after six months. The pathogen was easily re-isolated from seedlings and re-identified as V. dahliae, thus satisfying Koch’s postulates. Results from intraspecific resistance screening of nine seed sources from across Italy revealed that Ailanthus provenances from all the six sampled regions were susceptible to V. dahliae. Stem inoculated adult plants exhibited abundant production of epicormic sprouts along the stem within six months, and most of these sprouts wilted following initial dieback of the main stem; furthermore, sprouting from the crown was intense. Petioles and rachises tissues of leaves fallen from infected trees were a good source for re-isolation of the pathogen; we proved that such petioles and rachises can effectively transfer the fungus to healthy Ailanthus seedlings via root infections. Host-specificity of the V. dahliae isolate VdGL16 was also determined on 40 non-target species/varieties/cultivars. The isolate caused disease in herbaceous species belonging to five botanical families: Asteraceae, Lamiaceae, Leguminoseae, Linaceae and Solanaceae. Given the difficulties in countering Ailanthus invasion with mechanical and chemical methods, the biological control using Verticillium may provide an efficient, low cost and sustainable control of this invasive species. |
| first_indexed | 2024-12-20T21:18:59Z |
| format | Article |
| id | doaj.art-f03101c4811540f093b696358e877011 |
| institution | Directory Open Access Journal |
| issn | 1971-7458 1971-7458 |
| language | English |
| last_indexed | 2024-12-20T21:18:59Z |
| publishDate | 2020-06-01 |
| publisher | Italian Society of Silviculture and Forest Ecology (SISEF) |
| record_format | Article |
| series | iForest - Biogeosciences and Forestry |
| spelling | doaj.art-f03101c4811540f093b696358e8770112022-12-21T19:26:21ZengItalian Society of Silviculture and Forest Ecology (SISEF)iForest - Biogeosciences and Forestry1971-74581971-74582020-06-0113123824510.3832/ifor3238-0133238Verticillium wilt of Ailanthus altissima in Italy caused by V. dahliae: new outbreaks from TuscanyPisuttu C0Marchica A1Bernardi R2Calzone A3Cotrozzi L4Nali C5Pellegrini E6Lorenzini G7Department of Agriculture, Food and Environment of the University of Pisa, v. del Borghetto 80 - 56124 Pisa (Italy)Department of Agriculture, Food and Environment of the University of Pisa, v. del Borghetto 80 - 56124 Pisa (Italy)Department of Agriculture, Food and Environment of the University of Pisa, v. del Borghetto 80 - 56124 Pisa (Italy)Department of Agriculture, Food and Environment of the University of Pisa, v. del Borghetto 80 - 56124 Pisa (Italy)Department of Agriculture, Food and Environment of the University of Pisa, v. del Borghetto 80 - 56124 Pisa (Italy)Department of Agriculture, Food and Environment of the University of Pisa, v. del Borghetto 80 - 56124 Pisa (Italy)Department of Agriculture, Food and Environment of the University of Pisa, v. del Borghetto 80 - 56124 Pisa (Italy)Department of Agriculture, Food and Environment of the University of Pisa, v. del Borghetto 80 - 56124 Pisa (Italy)Verticillium spp., including V. nonalfalfae and V. dahliae, are known vascular wilt pathogens of the invasive Ailanthus altissima (tree-of-heaven) in the United States and in Europe. Herein we provide evidence of the presence of a previously unreported wilt disease of A. altissima in Tuscany (Central Italy). Several isolates were collected from two locations and identified as V. dahliae, based on microscopical features of conidiophores, conidia and microsclerotia. Genomic DNA was extracted from the mycelium, the ITS region was amplified and the sequence was deposited in GenBank as VdGL16 (accession no. MK474459). BLASTn analysis showed 100% similarity with V. dahliae. To confirm pathogenicity of VdGL16, inoculations of Ailanthus seedlings were performed with the root dipping technique whereas mature trees were stem-inoculated. All inoculated seedlings exhibited wilt symptoms after 20 days, while mature Ailanthus trees showed wilting and dieback after six months. The pathogen was easily re-isolated from seedlings and re-identified as V. dahliae, thus satisfying Koch’s postulates. Results from intraspecific resistance screening of nine seed sources from across Italy revealed that Ailanthus provenances from all the six sampled regions were susceptible to V. dahliae. Stem inoculated adult plants exhibited abundant production of epicormic sprouts along the stem within six months, and most of these sprouts wilted following initial dieback of the main stem; furthermore, sprouting from the crown was intense. Petioles and rachises tissues of leaves fallen from infected trees were a good source for re-isolation of the pathogen; we proved that such petioles and rachises can effectively transfer the fungus to healthy Ailanthus seedlings via root infections. Host-specificity of the V. dahliae isolate VdGL16 was also determined on 40 non-target species/varieties/cultivars. The isolate caused disease in herbaceous species belonging to five botanical families: Asteraceae, Lamiaceae, Leguminoseae, Linaceae and Solanaceae. Given the difficulties in countering Ailanthus invasion with mechanical and chemical methods, the biological control using Verticillium may provide an efficient, low cost and sustainable control of this invasive species.https://iforest.sisef.org/contents/?id=ifor3238-013tree-of-heavenverticillium dahliaeits regionaccession number mk474459koch’s postulatesbiocontrol |
| spellingShingle | Pisuttu C Marchica A Bernardi R Calzone A Cotrozzi L Nali C Pellegrini E Lorenzini G Verticillium wilt of Ailanthus altissima in Italy caused by V. dahliae: new outbreaks from Tuscany iForest - Biogeosciences and Forestry tree-of-heaven verticillium dahliae its region accession number mk474459 koch’s postulates biocontrol |
| title | Verticillium wilt of Ailanthus altissima in Italy caused by V. dahliae: new outbreaks from Tuscany |
| title_full | Verticillium wilt of Ailanthus altissima in Italy caused by V. dahliae: new outbreaks from Tuscany |
| title_fullStr | Verticillium wilt of Ailanthus altissima in Italy caused by V. dahliae: new outbreaks from Tuscany |
| title_full_unstemmed | Verticillium wilt of Ailanthus altissima in Italy caused by V. dahliae: new outbreaks from Tuscany |
| title_short | Verticillium wilt of Ailanthus altissima in Italy caused by V. dahliae: new outbreaks from Tuscany |
| title_sort | verticillium wilt of ailanthus altissima in italy caused by v dahliae new outbreaks from tuscany |
| topic | tree-of-heaven verticillium dahliae its region accession number mk474459 koch’s postulates biocontrol |
| url | https://iforest.sisef.org/contents/?id=ifor3238-013 |
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