1
|
Aloi F, Parlascino R, Conti Taguali S, Faedda R, Pane A, Cacciola SO. Phytophthora pseudocryptogea, P. nicotianae and P. multivora Associated to Cycas revoluta: First Report Worldwide. PLANTS (BASEL, SWITZERLAND) 2023; 12:1197. [PMID: 36904056 PMCID: PMC10005564 DOI: 10.3390/plants12051197] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/28/2023] [Accepted: 03/03/2023] [Indexed: 06/18/2023]
Abstract
A dieback was observed on three-year-old pot-grown plants of Cycas revoluta in Sicily (Italy). Symptoms, including stunting, yellowing and blight of the leaf crown, root rot and internal browning and decay of the basal stem, closely resembled the Phytophthora root and crown rot syndrome, common in other ornamentals. Isolations from rotten stem and roots, using a selective medium, and from rhizosphere soil of symptomatic plants, using leaf baiting, yielded three Phytophthora species, P. multivora, P. nicotianae and P. pseudocryptogea, were obtained. Isolates were identified by both morphological characters and DNA barcoding analysis, using three gene regions: ITS, β-tub and COI. Phytophthora pseudocryptogea was the sole species isolated directly from the stem and roots. The pathogenicity of the isolates of the three Phytophthora species was tested on one-year-old potted plants of C. revoluta, using both stem inoculation by wounding, and root inoculation through infested soil. Phytophthora pseudocryptogea was the most virulent and, like P. nicotianae, reproduced all the symptoms of natural infections, while P. multivora was the least virulent and induced solely very mild symptoms. Phytophthora pseudocryptogea was identified as the causal agent of the decline of C. revoluta, as it was re-isolated from both the roots and stems of artificially infected symptomatic plants, thus fulfilling Koch's postulates.
Collapse
|
2
|
Abstract
Paulownia species are fast growing trees native to China, which are being grown in managed plantings in several European countries for the production of wood and biomasses. In 2018, wilting, stunting, leaf yellowing, and collapse, as a consequence of root and crown rot, were observed in around 40% of trees of a 2-year-old planting of Paulownia elongata × P. fortunei in Calabria (Southern Italy). Two species of Phytophthora were consistently recovered from roots, basal stem bark, and rhizosphere soil of symptomatic trees and were identified as Ph. nicotianae and Ph. palmivora on the basis of both morphological characteristics and phylogenetic analysis of rDNA ITS sequences. Koch’s postulates were fulfilled by reproducing the symptoms on potted paulownia saplings transplanted into infested soil or stem-inoculated by wounding. Both Phytophthora species were pathogenic and caused root rot and stem cankers. Even though P. palmivora was the only species recovered from roots of naturally infected plants, in pathogenicity tests through infested soil P. nicotianae was more virulent. This is the first report of Phytophthora root and crown rot of a Paulownia species in Europe. Strategies to prevent this emerging disease include the use of healthy nursery plants, choice of well-drained soils for new plantations, and proper irrigation management.
Collapse
|
3
|
Wang T, Gao C, Cheng Y, Li Z, Chen J, Guo L, Xu J. Molecular Diagnostics and Detection of Oomycetes on Fiber Crops. PLANTS (BASEL, SWITZERLAND) 2020; 9:E769. [PMID: 32575466 PMCID: PMC7355704 DOI: 10.3390/plants9060769] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 11/16/2022]
Abstract
Fiber crops are an important group of economic plants. Traditionally cultivated for fiber, fiber crops have also become sources of other materials such as food, animal feed, cosmetics and medicine. Asia and America are the two main production areas of fiber crops in the world. However, oomycete diseases have become an important factor limiting their yield and quality, causing devastating consequences for the production of fiber crops in many regions. To effectively control oomycete pathogens and reduce their negative impacts on these crops, it is very important to have fast and accurate detection systems, especially in the early stages of infection. With the rapid development of molecular biology, the diagnosis of plant pathogens has progressed from relying on traditional morphological features to the increasing use of molecular methods. The objective of this paper was to review the current status of research on molecular diagnosis of oomycete pathogens on fiber crops. Our search of PubMed identified nearly 30 species or subspecies of oomycetes on fiber crops, among which the top three species were Phytophthora boehmeriae, Phytophthora nicotianae and Pythium ultimum. The gene regions that have been used for molecular identifications of these pathogens include the internal transcribed spacer (ITS) regions of the nuclear ribosomal RNA gene cluster, and genes coding for translation elongation factor 1α (EF-1α) and mitochondrial cytochrome c oxidase subunits I and II (Cox 1, Cox 2), etc. We summarize the molecular assays that have been used to identify these pathogens and discuss potential areas of future development for fast, specific, and accurate diagnosis of oomycetes on fiber crops.
Collapse
Affiliation(s)
- Tuhong Wang
- Institute of Bast Fiber Crops and Center of Southern Economic Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, China; (T.W.); (C.G.); (Y.C.); (Z.L.); (J.C.); (L.G.)
| | - Chunsheng Gao
- Institute of Bast Fiber Crops and Center of Southern Economic Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, China; (T.W.); (C.G.); (Y.C.); (Z.L.); (J.C.); (L.G.)
| | - Yi Cheng
- Institute of Bast Fiber Crops and Center of Southern Economic Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, China; (T.W.); (C.G.); (Y.C.); (Z.L.); (J.C.); (L.G.)
| | - Zhimin Li
- Institute of Bast Fiber Crops and Center of Southern Economic Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, China; (T.W.); (C.G.); (Y.C.); (Z.L.); (J.C.); (L.G.)
| | - Jia Chen
- Institute of Bast Fiber Crops and Center of Southern Economic Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, China; (T.W.); (C.G.); (Y.C.); (Z.L.); (J.C.); (L.G.)
| | - Litao Guo
- Institute of Bast Fiber Crops and Center of Southern Economic Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, China; (T.W.); (C.G.); (Y.C.); (Z.L.); (J.C.); (L.G.)
| | - Jianping Xu
- Institute of Bast Fiber Crops and Center of Southern Economic Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, China; (T.W.); (C.G.); (Y.C.); (Z.L.); (J.C.); (L.G.)
- Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada
| |
Collapse
|
4
|
Puglisi I, De Patrizio A, Schena L, Jung T, Evoli M, Pane A, Van Hoa N, Van Tri M, Wright S, Ramstedt M, Olsson C, Faedda R, Magnano di San Lio G, Cacciola SO. Two previously unknown Phytophthora species associated with brown rot of Pomelo (Citrus grandis) fruits in Vietnam. PLoS One 2017; 12:e0172085. [PMID: 28208159 PMCID: PMC5313238 DOI: 10.1371/journal.pone.0172085] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 01/31/2017] [Indexed: 11/19/2022] Open
Abstract
Two distinct Phytophthora taxa were found to be associated with brown rot of pomelo (Citrus grandis), a new disease of this ancestral Citrus species, in the Vinh Long province, Mekong River Delta area, southern Vietnam. On the basis of morphological characters and using the ITS1-5.8S-ITS2 region of the rDNA and the cytochrome oxidase subunit 1 (COI) as barcode genes, one of the two taxa was provisionally named as Phytophthora sp. prodigiosa, being closely related to but distinct from P. insolita, a species in Phytophthora Clade 9, while the other one, was closely related to but distinct from the Clade 2 species P. meadii and was informally designated as Phytophthora sp. mekongensis. Isolates of P. sp. prodigiosa and P. sp. mekongensis were also obtained from necrotic fibrous roots of Volkamer lemon (C. volkameriana) rootstocks grafted with 'King' mandarin (Citrus nobilis) and from trees of pomelo, respectively, in other provinces of the Mekong River Delta, indicating a widespread occurrence of both Phytophthora species in this citrus-growing area. Koch's postulates were fulfilled via pathogenicity tests on fruits of various Citrus species, including pomelo, grapefruit (Citrus x paradisi), sweet orange (Citrus x sinensis) and bergamot (Citrus x bergamia) as well as on the rootstock of 2-year-old trees of pomelo and sweet orange on 'Carrizo' citrange (C. sinensis 'Washington Navel' x Poncirus trifoliata). This is the first report of a Phytophthora species from Clade 2 other than P. citricola and P. citrophthora as causal agent of fruit brown rot of Citrus worldwide and the first report of P. insolita complex in Vietnam. Results indicate that likely Vietnam is still an unexplored reservoir of Phytophthora diversity.
Collapse
Affiliation(s)
- Ivana Puglisi
- Department of Agriculture, Food and Environment, University of Catania, Catania, Italy
- Dipartimento di Agraria, Università Mediterranea di Reggio Calabria, Feo di Vito, Reggio Calabria, Italy
| | | | - Leonardo Schena
- Dipartimento di Agraria, Università Mediterranea di Reggio Calabria, Feo di Vito, Reggio Calabria, Italy
| | - Thomas Jung
- Phytophthora Research Center Mendel University, Zemedelska 1, 613 00 Brno, Czech Republic
- Phytophthora Research and Consultancy, Am Rain 9, Nußdorf, Germany
| | - Maria Evoli
- Department of Agriculture, Food and Environment, University of Catania, Catania, Italy
| | - Antonella Pane
- Department of Agriculture, Food and Environment, University of Catania, Catania, Italy
| | - Nguyen Van Hoa
- Southern Horticultural Research Institute, My Tho, Tien Giang, Vietnam
| | - Mai Van Tri
- Southern Horticultural Research Institute, My Tho, Tien Giang, Vietnam
| | - Sandra Wright
- Department of Electronics, Mathematics and Natural Sciences, University of Gävle, Gävle, Sweden
| | - Mauritz Ramstedt
- Department of Forest Mycology and Plant Pathology, Swedish Agricultural University (SLU), Uppsala, Sweden
| | - Christer Olsson
- Department of Biological and Environmental Sciences, Gothenburg University, Gothenburg, Sweden
| | - Roberto Faedda
- Department of Agriculture, Food and Environment, University of Catania, Catania, Italy
| | - Gaetano Magnano di San Lio
- Dipartimento di Agraria, Università Mediterranea di Reggio Calabria, Feo di Vito, Reggio Calabria, Italy
| | - Santa Olga Cacciola
- Department of Agriculture, Food and Environment, University of Catania, Catania, Italy
| |
Collapse
|