Naslov
Biology and variability of Citrus tristeza virus, a long-known plant pathogen still able to cause sadness in humans

Autori
Škorić, Dijana

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
4th Croatian Congress of Microbiology with international partcicipation, Programme and Abstracts / Vujaklija, Dušica ; Pigac, Jasenka ; Hađina, Suzana ; Kosalec, Ivan - Zagreb : Hrvatsko mikrobiološko društvo, 2008, 24-24

ISBN
978-953-96567-7-3

Skup
4th Croatian Congress of Microbiology with international partcicipation

Mjesto i datum
Zadar, Hrvatska, 24.09.2008. - 27.09.2008

Vrsta sudjelovanja
Plenarno

Vrsta recenzije
Domaća recenzija

Ključne riječi
Closterovirus; CTV; stem-pitting; molecular and biological characterization; population structure; epidemiology

Sažetak
For citrus growers, tristeza (sadness) is not only the mood but also devastating news of a plant disease whose agent is Citrus tristeza virus (CTV). With a few exceptions, this Closterovirus replicates only in the phloem cells of citrus species. Virions are threadlike, 2000x11 nm in size with a (+)RNA genome of 19.3 kb organized into 12 open reading frames. Depending on the virus strain, scion cultivar and rootstock, CTV induces one of the three syndromes: decline or tristeza sensu stricto, stem pitting (SP) and seedling yellows. All have serious economic consequences but the worst is the extreme form of decline called quick decline because infected tree can perish in a few weeks. Mild strains of CTV also exist. They remain unnoticed in the field because symptoms are not apparent in many scion/rootstock combinations but even these strains can represent phytopathological hazard if transmitted to new hosts, new geographical areas, or if the virus population drastically changes. Aphids naturally spread the virus and Toxoptera citricida is the most efficient vector. Aphid transmission is significant locally while long-distance dispersal of the virus is done mostly by man (grafting, import of infected planting material). Nonetheless, since invasive T. citricida has recently been recorded in Europe, it has become a threat to the Mediterranean citrus industry. In the field, CTV usually exists as a mixture of strains. The current basis for the strain differentiation is biological characterization in selected citrus indicators. These biogroups are correlated to the variability found in the CTV coat protein gene but the real pathogenicity determinants remain unknown. Croatian CTV field isolates are much more diverse than expected. Moreover, severe SP strains were identified from Satsuma mandarins that have the highest tolerance to this syndrome. A single filed tree is often found infected with CTV isolates from different phylogenetic groups. Driving forces that shape CTV populations encompass different mechanisms common to RNA-virus populations, as well as human and other natural influences primarily regarding the type of virus dispersal. The epidemiological significance of our local CTV populations witin the Mediterranean will be discussed.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

Napomena
Navedeni su samo editors in chief za knjigu sažetaka.

POVEZANOST RADA