Browsing by Author "Gatin, Z."
Now showing 1 - 3 of 3
Results Per Page
Sort Options
- Citrus wilsonii: Biological response to infection with different citrus tristeza virus genotypesPublication . Hancevic, K.; Cerni, S.; Nolasco, Gustavo; Radic, T.; Rosin, J.; Gatin, Z.; Skoric, D.Citrus wilsonii Tanaka is cold-resistant, rarely grown chance hybrid between Citrus ichangensis and Citrus grandis with a potential to be used as a rootstock in colder climates. In order to evaluate its reaction to Citrus tristeza virus (CTV), C. wilsonii seedlings were graft-inoculated with previously characterized CTV isolates monophyletic with respect to the p25 gene and clustering to phylogenetic groups Gp 1, Gp 2, Gp 3a, Gp 4, Gp 5 and Gp M. The evaluation of C. wilsonii symptoms and comparison with the reaction of standard citrus indicators infected with the same CTV isolates revealed that C. wilsonii infected with isolates Gp 2 and Gp 4 developed stem pitting (SP). This is in accordance with the SP-inducing potential of these CTV isolates in the standard sweet orange SP indicator. The obvious and numerous pits shown by C. wilsonii stems suggests that it reacts strongly to severe SP CTV isolates.
- Occurrence of stem-pitting strains of Citrus tristeza virus in CroatiaPublication . Cerni, S.; Skoric, D.; Krajacic, M.; Gatin, Z.; Santos, C.; Martins, V.; Nolasco, GustavoCitrus is grown in Croatia (approximately 1,500 ha of citrus groves) on the Dalmatian Coast and Islands between 42 and 43°30'N. The major species, Citrus unshiu Marc. (Satsuma mandarin), is grafted on trifoliate rootstock. The presence of Citrus tristeza virus (CTV) in Satsumas in the Neretva Valley Region was previously reported (3). During the course of a biomolecular characterization of isolates from Croatia, 15 budsticks were collected from field- infected, enzyme-linked immunosorbent assay (ELISA)-positive sources during the autumn of 2003 near Kaštela, Split, Metković (Neretva Valley), and on the island of Vis. Isolates were propagated by graft transmission to Madam Vinous sweet orange (SwO) and maintained in an insect-proof greenhouse at 21 to 33° C.
- Stem pitting and seedling yellows symptoms of Citrus tristeza virus infection may be determined by minor sequence variantsPublication . Cerni, S.; Ruscic, J.; Nolasco, Gustavo; Gatin, Z.; Krajacic, M.; Skoric, D.The isolates of Citrus tristeza virus (CTV), the most destructive viral pathogen of citrus, display a high level of variability. As a result of genetic bottleneck induced by the bud-inoculation of CTV-infected material, inoculated seedlings of Citrus wilsonii Tanaka displayed different symptoms. All successfully grafted plants showed severe symptoms of stem pitting and seedling yellows, while plants in which inoculated buds died displayed mild symptoms. Since complex CTV population structure was detected in the parental host, the aim of this work was to investigate how it changed after the virus transmission, and to correlate it with observed symptoms. The coat protein gene sequence of the predominant genotype was identical in parental and grafted plants and clustered to the phylogenetic group 5 encompassing severe reference isolates. In seedlings displaying severe symptoms, the low-frequency variants clustering to other phylogenetic groups were detected, as well. Indicator plants were inoculated with buds taken from unsuccessfully grafted C. wilsonii seedlings. Surprisingly, they displayed no severe symptoms despite the presence of phylogenetic group 5 genomic variants. The results suggest that the appearance of severe symptoms in this case is probably induced by a complex CTV population structure found in seedlings displaying severe symptoms, and not directly by the predominant genomic variant.