ISHS Acta Horticulturae 472: XVII International Symposium Virus and Virus-Like Diseases of Temperate Fruit Crops
VECTORS AS EPIDEMIOLOGICAL FACTORS IN WIDENING THE HOST RANGE FOR VIRUSES OF FRUIT TREES AND SMALL FRUIT CROPS |
| Authors: | M. Keldish, Y. Pomazkov, E. Arushanova, O. Chervyakova |
| Abstract:
As a result of comprehensive virological analyses of the collections at the Main Botanical Garden of the Russian Academy of Sciences, we propose an expansion of the established host range of fruit and small fruit crop viruses. As a rule, multiple pathological complexes are formed by infection of fruit trees with non-specific viruses which are transmitted by vectors. New pathological relationships between viruses which are transmitted by aphids and nematodes were recognize as a result of assimilation of new trophic plants. The occurrence of various types of transmission among viruses and polyphagy of the vectors provides them with greater adaptivity and competitiveness under biocenotic conditions. Formation of the new pathological complexes takes place along with quantitative and qualitative changes of both viruses and vectors as well as the etiology and infection rate. We have discovered new types of alternative hosts for plum pox virus, arabis mosaic virus, raspberry ringspot virus, tomato black ring virus and tomato ringspot virus in different taxons (Saxifragaceae, Leguminosae, Compositae, Gramineae, Caprifoliaceae, Ericaceae). Using representatives of the genus Prunus, such as Amygdalus, Armeniaca, and Cerasus, we diagnosed such viruses as bean yellow mosaic virus, alfalfa mosaic virus, potato virus Y, tulip braeking virus, brome mosaic virus, and cucumber mosaic virus. Study of the role of the etiology of these viruses belonging to different taxonomic groups indicates possible increases in infection rate and in the number combinations of pathogenic organisms, as well as changes in symptomatology and vector range. Non-specific relationships were also discovered between vectors and viruses, for example, the transmission rate of bean yellow mosaic virus is 15 – 20% and is 10 – 12% for tulip braeking virus via the vector Rhopalosiphon padi (L.). Potato virus Y is transmitted at a rate of 20 – 25% by the vector Hyalopterus pruni (Geoffr.). Myzus persicae (Sulz), M. cerasi (F.), H. pruni (Geoffr.), and Brachycardus cardui (L.) biotypes were discovered in the total population of aphids on fruit trees which differ in vector qualities and their range of fodder type. Trophic connections between the vectors and host plants increase the number of plant species involved in the pathogenic process. Therefore, polyphagy of the vector could provide viruses with opportunities to extend their host range and to create conditions for multiple infection formation. | |
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