Tuesday, December 11, 2001 -

Survey of the distribution of phytoplasmas in wine grapes and possible vectors in the Golan Heights, Israel and development of specific primers

Sigalit Orenstein, Northern Research and Development, Industrial Area, Kiryat Sh'mona, Israel, Tirtza Zahavi, Extension Service, M.O.P, Katzrin, Israel, and Phyllis Weintraub, Agricultural Research Organization, Entomology, D. N. Negev, Gilat Research Station, Israel.

The Golan Heights in Israel is a comparatively new, but economically important, wine-grape area; the first vineyards were planted only 25 years ago. It was known that three types of phytoplasmas occur in grapevines in Israel; however, the composition and distribution of phytoplasmas in the Golan Heights, was unknown. The topography over the 50 km length of the Heights ranges from an altitude of 1000 m in the north to 300 m in the south. Soil in the Heights is of volcanic origin. Winter and summer temperatures very greatly between the northern and southern limits. Our survey sampled four of the most prevalent cultivars in three sub-regions of the Heights; north, center and south. Analysis of leaves from plants showing signs and symptoms of phytoplasma infection were made with PCR and RFLP. Stolbur was found to be the predominant phytoplasma (~73% of all infections), although Aster Yellow (~9%), Western-X (~4%) and mixtures of two phytoplasmas (90% of which involved Stolbur and AY) were also found. Yellow sticky traps were used to monitor potential vectors; 20 traps surrounded a vineyard in the north and center of the Golan Heights. Two species of leafhoppers, Neoaliturus fenestratus and Megophthalmus scabripennis, were found in very large numbers and were found to be positive for phytoplasmas by PCR. The number of leafhoppers found in the cooler, northern Heights were significantly fewer than in the central Heights. Prior research on phytoplasmas of grapevines in Israel involved the use of two sets of universal primers. Primers were developed specifically for phytoplasmas occurring in Israel in which there were homologies of 90, 85 and 78% for Stolbur, AY and W-X phytoplasmas, respectively. Use of these new primers for insect and plants samples will reduce biochemical analysis costs by 50%.

Species 1: Homoptera Cicadellidae Neoaliturus fenestratus
Species 2: Homoptera Cicadellidae Megophthalmus scabripennis
Keywords: stolbur, aster yellows

The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA