Viry česneku přenosné roztoči

Dipl.-Ing. Faten Mansouri

Disertační práce

Garlic viruses transmitted by mites

Anotace:

Allexivirus is a genus of the family Alphaflexiviridae. Since this genus was first described in 1970 by Razvjakina, Allexivirus species were reported all around the world. Although this genus primarily infects the family Amaryllidaceae, it is also able to infect hosts from Fabaceae, Rosaceae and Orchidaceae. To date, thirteen species have been assigned to the genus. Eight species have been reported to be restricted to Allium species: shallot virus X (ShVX), garlic virus A (GarV-A), garlic virus B (GarV-B), garlic virus C (GarV-C), garlic virus D (GarV-D), garlic virus E (GarV-E), garlic virus X (GarV-X), and garlic-mite filamentous virus (GarMbFV) and five described from non-Allium hosts: blackberry virus E (BVE), vanilla latent virus (VLV), alfalfa virus S (AVS), Arachis pintoi virus (ApV), and Severe yellow mosaic virus (SSYMV). The Allium-infecting allexiviruses have been discovered all over the world including the Czech Republic. These allexiviruses often occur in mixed infection with viruses from different families including Potyviridae (genus Potyvirus), Betaflexiviridae (genus Carlavirus) and Tospoviridae (genus Orthotospovirus). The goal of the study was to investigate the distribution of allexiviruses, their occurrence in mixed infection, and the host range of these viruses in the Czech Republic. Another goal of the study was to determine the transmission characteristics of the member of the genus Allexivirus. The study was carried out during three growing seasons (2016-2018) in four different regions of the Czech Republic (Prague, Průhonice, Brno and Olomouc). During vegetation period, 65 vegetable, wild and ornamental Allium species cultivated or naturally occurring were collected from six habitat categories (botanical gardens, private gardens, cultivated fields, ornamentals from markets, cultivated plants of wild origin and wild origin) and tested for the presence of fifteen viruses. Most of the collected samples were infected by at least one or more virus(es). The infection rate of Allium samples differed depending on the habitat origin and phylogenetic relatedness of the hosts. Viruses were most frequently detected on cultivated species and low infection rates and virus free samples were detected on species of wild origin. Allium-infecting allexiviruses have been reported to be transmitted by eriophyoid mites, Aceria tulipae. However, little is known about their transmission characteristics. The transmission characteristics of members of the genus Allexivirus to leek (Allium porrum L.) by its eriophyid mite vector, Aceria tulipae (Keifer), were studied. Prior to conducting transmission tests, colonies of nonviruliferous A. tulipae were established on healthy leek seedlings. None of the mites that originated from eggs deposited on infected plants transmitted allexiviruses, indicating that the viruses are not transmitted transovarially. Acquisition access period, inoculation access period, and retention period tests, suggest a semi-persistent mode of transmission of Allexivirus members by A. tulipae. The data from this study provide a useful basis and reveal several practical applications of future research. The understanding of the biology of allexiviruses, their occurrence in mixed infection, their spread, transmission, and host range is an important and essential key research to be able to choose appropriate method of protection of plants against these viruses.

Abstract:

Allexivirus is a genus of the family Alphaflexiviridae. Since this genus was first described in 1970 by Razvjakina, Allexivirus species were reported all around the world. Although this genus primarily infects the family Amaryllidaceae, it is also able to infect hosts from Fabaceae, Rosaceae and Orchidaceae. To date, thirteen species have been assigned to the genus. Eight species have been reported to be restricted to Allium species: shallot virus X (ShVX), garlic virus A (GarV-A), garlic virus B (GarV-B), garlic virus C (GarV-C), garlic virus D (GarV-D), garlic virus E (GarV-E), garlic virus X (GarV-X), and garlic-mite filamentous virus (GarMbFV) and five described from non-Allium hosts: blackberry virus E (BVE), vanilla latent virus (VLV), alfalfa virus S (AVS), Arachis pintoi virus (ApV), and Severe yellow mosaic virus (SSYMV). The Allium-infecting allexiviruses have been discovered all over the world including the Czech Republic. These allexiviruses often occur in mixed infection with viruses from different families including Potyviridae (genus Potyvirus), Betaflexiviridae (genus Carlavirus) and Tospoviridae (genus Orthotospovirus). The goal of the study was to investigate the distribution of allexiviruses, their occurrence in mixed infection, and the host range of these viruses in the Czech Republic. Another goal of the study was to determine the transmission characteristics of the member of the genus Allexivirus. The study was carried out during three growing seasons (2016-2018) in four different regions of the Czech Republic (Prague, Průhonice, Brno and Olomouc). During vegetation period, 65 vegetable, wild and ornamental Allium species cultivated or naturally occurring were collected from six habitat categories (botanical gardens, private gardens, cultivated fields, ornamentals from markets, cultivated plants of wild origin and wild origin) and tested for the presence of fifteen viruses. Most of the collected samples were infected by at least one or more virus(es). The infection rate of Allium samples differed depending on the habitat origin and phylogenetic relatedness of the hosts. Viruses were most frequently detected on cultivated species and low infection rates and virus free samples were detected on species of wild origin. Allium-infecting allexiviruses have been reported to be transmitted by eriophyoid mites, Aceria tulipae. However, little is known about their transmission characteristics. The transmission characteristics of members of the genus Allexivirus to leek (Allium porrum L.) by its eriophyid mite vector, Aceria tulipae (Keifer), were studied. Prior to conducting transmission tests, colonies of nonviruliferous A. tulipae were established on healthy leek seedlings. None of the mites that originated from eggs deposited on infected plants transmitted allexiviruses, indicating that the viruses are not transmitted transovarially. Acquisition access period, inoculation access period, and retention period tests, suggest a semi-persistent mode of transmission of Allexivirus members by A. tulipae. The data from this study provide a useful basis and reveal several practical applications of future research. The understanding of the biology of allexiviruses, their occurrence in mixed infection, their spread, transmission, and host range is an important and essential key research to be able to choose appropriate method of protection of plants against these viruses.

Klíčová slova

Allium, Allexivirus, Aceria tulipae, Orthotospovirus, carlavirus, potyvirus

Keywords

Allium, Allexivirus, Carlavirus, Potyvirus, Aceria tulipae, Orthotospovirus

Jazyk práce: čeština

Datum vytvoření / odevzdání či podání práce: 23. 8. 2021

Obhajoba závěrečné práce

• Vedoucí: prof. Ing. Pavel Ryšánek, CSc.

Česká zemědělská univerzita v Praze

Fakulta agrobiologie, potravinových a přírodních zdrojů

Doktorský studijní program / obor:
Zemědělská specializace / Zemědělská a lesnická fytopatologie a ochrana rostlin