The apple scar skin disease was first re- ported 60 years ago in China ( Manchuria) with the name “Manshu-sabika-byo” (19). Twenty years later, two apple. Cause These diseases are caused by Apple scar skin viroid. Many infected cultivars of apple or pear do not express symptoms of disease. Apple scar skin viroid(ASSVd), a pathogenic RNA viroid, infects apple and pear trees. To determine if ASSVd can also infect apricot, we performed reverse.

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Sundararaj, Institute of Wood Science and Technology, Bengaluru, Karnataka, India for his help in identification of the whitefly species as Trialeurodes vaporariorum.

Dot blot hybridization of the various plants inoculated through whitefly: Side box indicates size of the different fragments bp, bp, bp, bp and bp obtained after digestion of RCA product in case of viroidliferous whitefly.

Sequence alignment between the ubiquitin ligase mRNA and ASSVd primers indicated high sequence similarity between the 2, thus explaining why this amplicon was obtained Fig. The emergence and dissemination of whitefly-transmitted geminiviruses in Latin America. Results and Discussion A healthy Tv colony was maintained on seed-grown eggplant Solanum melongena.

Please review our privacy policy. A GroEL homologue from endosymbiotic bacteria of the whitefly Bemisia tabaci is implicated in the circular transmission of Tomato yellow leaf curl virus. If you would like to, you can learn more about the cookies we use. All of these results led us to identify a role for PP2 in viroid transfer and its translocation as a complex from the plant to the whitefly.


J Virol ; This is especially important for apple viroids when considering the low-chilling cultivars of apple grown at low altitudes, where apple, herbaceous hosts and Tv are in close association. However, in Hebei, China, the Chinese pear P. Continuing to use www. Natural infection of wild and cultivated pears with Apple scar skin viroid in Greece. Of the more than whitefly species described to date, only Bemisia and Trialeurodes whiteflies are known to be viral vectors, including B.

This is IHBT publication number Scar skin and dapple apple viroids are seed-borne and persistent in infected apple trees. This experimental transfer also confirmed that the whitefly could take up naked RNA and transmit it, perhaps with the aid of certain whitefly proteins. The authors thank Prof. Arabidopsis thaliana has the enzymatic machinery for replicating representative viroid species of the family Pospiviroidae.

Some RNA species possess stem loop structures similar to tRNAs, and the existence of other unknown RNAs with such structures, which can confer increased stability, is probable. Bulletins of Nagano Hort.

Apple scar skin viroid (ASSVD0)[Overview]| EPPO Global Database

Nucleic acid transfer between plants is a phenomenon which is likely to occur in many ways in nature. A proposed scheme for viroid classification qpple nomenclature.

Molecular characterization of Apple scar skin viroid from Himalayan wild cherry. Plant Pathol ; To explore the identity of this DNA form, rolling circle amplification RCA was wpple using viroidliferous and healthy whiteflies. As viroid-like secondary structures are found in some plant RNAs, and PP2 is known to bind and translocate several RNAs, the results have huge implications in transfer of these RNA species between plants visited by the whitefly.


apple dimple (Apple scar skin viroid)

Furthermore, the B biotype vector zcar invasive and displaces other biotypes. Although the amplified fragment was not affected by this treatment, it disappeared when the whitefly DNA was incubated with DNase and then examined using PCR not shown. Go to distribution map To our surprise, the non-specific bp amplicon was neither of whitefly origin nor a mutated shorter form of the viroid, as is known in the case of CaSVd-like RNA.

However, there are no reports of direct insect vector transmission of viroids or the presence of viroid DNA DNA in insects. Disclosure of Potential Conflicts of Interest No potential conflicts of interest were disclosed. Varma A, Malathi VG. This circular DNA was linearized to a 2.

In addition to the monomeric circular and monomeric linear bands, another band was observed in the whiteflies, which may correspond to replicative intermediates of viroid RNA. To screen for the presence of viroid in the viroidliferous whiteflies, we analyzed monomeric circular and linear RNAs. Ralls Janet, water-soaked blotches appear first, followed by scar tissue, and then cracking.

However, the role of plant host factors in determining the transmission efficiency cannot be overlooked.