Effect of Necrosis Caused by Rhizobium vitis on Graft Take on Widely Grown Grape Cultivars and Rootstocks and Their Reaction to Necrosis

The effects of necrosis caused by Rhizobium vitis (R. vitis) on the graft take of some grape cultivars and American grapevine rootstocks commonly grown in our country and necrosis reactions of these cultivar/rootstock combinations were investigated. For this purpose, the performance of three different grape cultivars that is commonly growth as table, wine and dry on four different rootstocks were determined. According to the necrosis capacity on the green grapevine shoots in the in vitro, R. vitis MG2 strains were selected and inoculated to the graft surface of the cultivars and the rootstocks and basal part of the rootstocks prior to omega graft with a concentration of OD600:105cfu/ml. The results were evaluated after 16 weeks. The most resistant cultivar/rootstock combination was determined as Alphonse Lavallée (AL) / 5BB in terms of graft take and necrosis formation. Sultani ？ekirdeksiz (S？) is the most susceptible cultivar in terms of graft take and 1613C is the most susceptible rootstock. It was found that 5BB was the least affected rootstock by the necrosis within the combinations and the reactions of 1103P, 110R and 1613C rootstocks to necrosis were found similar. Although root formation was generally observed in all combinations, it was determined that root formation was substantially inhibited in the combinations of AL/110R and S？/5BB where the roots formed were necrotic