Evaluation of the Antifungal Activity of Endophytic and Rhizospheric Bacteria against Grapevine Trunk Pathogens
Grapevine trunk diseases (GTDs) are caused by multiple unrelated fungal pathogens, and their management remains difficult worldwide. Biocontrol is an attractive and sustainable strategy given the current need for a cleaner viticulture. In this study, twenty commercial vineyards were sampled across C...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-10-01
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| Series: | Microorganisms |
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| Online Access: | https://www.mdpi.com/2076-2607/10/10/2035 |
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| author | Marcelo I. Bustamante Karina Elfar Akif Eskalen |
| author_facet | Marcelo I. Bustamante Karina Elfar Akif Eskalen |
| author_sort | Marcelo I. Bustamante |
| collection | DOAJ |
| description | Grapevine trunk diseases (GTDs) are caused by multiple unrelated fungal pathogens, and their management remains difficult worldwide. Biocontrol is an attractive and sustainable strategy given the current need for a cleaner viticulture. In this study, twenty commercial vineyards were sampled across California to isolate endophytic and rhizospheric bacteria from different grapevine cultivars with the presence and absence of GTD symptoms. A collection of 1344 bacterial isolates were challenged in vitro against <i>Neofusicoccum parvum</i> and <i>Diplodia seriata</i>, from which a subset of 172 isolates exerted inhibition levels of mycelial growth over 40%. Bacterial isolates were identified as <i>Bacillus velezensis</i> (<i>n =</i> 154), <i>Pseudomonas</i> spp. (<i>n =</i> 12), <i>Serratia plymuthica</i> (<i>n =</i> 2) and others that were later excluded (<i>n =</i> 4). Representative isolates of <i>B. velezensis</i>, <i>P. chlororaphis,</i> and <i>S. plymuthica</i> were challenged against six other fungal pathogens responsible for GTDs. Mycelial inhibition levels were consistent across bacterial species, being slightly higher against slow-growing fungi than against Botryosphaeriaceae. Moreover, agar-diffusible metabolites of <i>B. velezensis</i> strongly inhibited the growth of <i>N. parvum</i> and <i>Eutypa lata</i>, at 1, 15, and 30% <i>v</i>/<i>v</i>. The agar-diffusible metabolites of <i>P. chlororaphis</i> and <i>S. plymuthica</i>, however, caused lower inhibition levels against both pathogens, but their volatile organic compounds showed antifungal activity against both pathogens. These results suggest that <i>B. velezensis</i>, <i>P. chlororaphis</i> and <i>S. plymuthica</i> constitute potential biocontrol agents (BCAs) against GTDs and their application in field conditions should be further evaluated. |
| first_indexed | 2024-03-09T19:44:06Z |
| format | Article |
| id | doaj.art-23261cfe1c5a451e9a4984cf377ae9e2 |
| institution | Directory Open Access Journal |
| issn | 2076-2607 |
| language | English |
| last_indexed | 2024-03-09T19:44:06Z |
| publishDate | 2022-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Microorganisms |
| spelling | doaj.art-23261cfe1c5a451e9a4984cf377ae9e22023-11-24T01:27:21ZengMDPI AGMicroorganisms2076-26072022-10-011010203510.3390/microorganisms10102035Evaluation of the Antifungal Activity of Endophytic and Rhizospheric Bacteria against Grapevine Trunk PathogensMarcelo I. Bustamante0Karina Elfar1Akif Eskalen2Department of Plant Pathology, University of California, Davis, CA 95616, USADepartment of Plant Pathology, University of California, Davis, CA 95616, USADepartment of Plant Pathology, University of California, Davis, CA 95616, USAGrapevine trunk diseases (GTDs) are caused by multiple unrelated fungal pathogens, and their management remains difficult worldwide. Biocontrol is an attractive and sustainable strategy given the current need for a cleaner viticulture. In this study, twenty commercial vineyards were sampled across California to isolate endophytic and rhizospheric bacteria from different grapevine cultivars with the presence and absence of GTD symptoms. A collection of 1344 bacterial isolates were challenged in vitro against <i>Neofusicoccum parvum</i> and <i>Diplodia seriata</i>, from which a subset of 172 isolates exerted inhibition levels of mycelial growth over 40%. Bacterial isolates were identified as <i>Bacillus velezensis</i> (<i>n =</i> 154), <i>Pseudomonas</i> spp. (<i>n =</i> 12), <i>Serratia plymuthica</i> (<i>n =</i> 2) and others that were later excluded (<i>n =</i> 4). Representative isolates of <i>B. velezensis</i>, <i>P. chlororaphis,</i> and <i>S. plymuthica</i> were challenged against six other fungal pathogens responsible for GTDs. Mycelial inhibition levels were consistent across bacterial species, being slightly higher against slow-growing fungi than against Botryosphaeriaceae. Moreover, agar-diffusible metabolites of <i>B. velezensis</i> strongly inhibited the growth of <i>N. parvum</i> and <i>Eutypa lata</i>, at 1, 15, and 30% <i>v</i>/<i>v</i>. The agar-diffusible metabolites of <i>P. chlororaphis</i> and <i>S. plymuthica</i>, however, caused lower inhibition levels against both pathogens, but their volatile organic compounds showed antifungal activity against both pathogens. These results suggest that <i>B. velezensis</i>, <i>P. chlororaphis</i> and <i>S. plymuthica</i> constitute potential biocontrol agents (BCAs) against GTDs and their application in field conditions should be further evaluated.https://www.mdpi.com/2076-2607/10/10/2035biocontrolendophytesrhizobacteriagrapevine trunk diseases |
| spellingShingle | Marcelo I. Bustamante Karina Elfar Akif Eskalen Evaluation of the Antifungal Activity of Endophytic and Rhizospheric Bacteria against Grapevine Trunk Pathogens Microorganisms biocontrol endophytes rhizobacteria grapevine trunk diseases |
| title | Evaluation of the Antifungal Activity of Endophytic and Rhizospheric Bacteria against Grapevine Trunk Pathogens |
| title_full | Evaluation of the Antifungal Activity of Endophytic and Rhizospheric Bacteria against Grapevine Trunk Pathogens |
| title_fullStr | Evaluation of the Antifungal Activity of Endophytic and Rhizospheric Bacteria against Grapevine Trunk Pathogens |
| title_full_unstemmed | Evaluation of the Antifungal Activity of Endophytic and Rhizospheric Bacteria against Grapevine Trunk Pathogens |
| title_short | Evaluation of the Antifungal Activity of Endophytic and Rhizospheric Bacteria against Grapevine Trunk Pathogens |
| title_sort | evaluation of the antifungal activity of endophytic and rhizospheric bacteria against grapevine trunk pathogens |
| topic | biocontrol endophytes rhizobacteria grapevine trunk diseases |
| url | https://www.mdpi.com/2076-2607/10/10/2035 |
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