Relationship between quince fruit deformation virus and some pome fruit viruses

Abstract

Infective fruit deformation is widely spread on the leading quince cultivar Leskovaćka in Yugoslavia. Virus-specific dsRNAs were isolated from naturally, as well as artificially infected cv. Leskovaćka trees, which indicates the viral etiology of the disease although no viruses could be isolated on herbaceous plants. Similar symptoms have been described in other countries mainly on indicator plants C 7/1. The objective of this paper was to assess the relationship of quince fruit deformation associated virus (QFDV) with pear vein yellows virus (PVYV) and apple stem pitting virus (ASPV). This was achieved by biological tests on woody indicator plants, inoculation of healthy cv. Leskovaćka plants with different PVYV isolates, and comparative analyses of dsRNAs from woody and herbaceous plants infected with different isolates of those viruses. Some QFDV isolates induced vein yellows on J d'Airolles, as did all PVYV isolates, and quince sooty ringspot (QSRS) on C. oblonga Pigwa 1, as did some of PVYV isolates. Also, PVYV isolates used for the inoculation of healthy cv. Leskovaćka induced QSRS on the leaves of this cultivar, which indicates their close relatedness. The slowest-migrating dsRNA of QFDV-infected quince comigrated with dsRNA with the highest molecular weight of all PVYV isolates, as well as with an ASPV isolate. Also, partial or complete identity was found between dsRNAs with low-molecular weight, which allows a preliminary identification of QFDV as a strain of PVYV, i.e. ASPV.