Survival of introduced Tuber melanosyorum at two sites in Israel as measured by occurrence of mycorrhizas

In the framework of efforts to introduce Tuber melanosporum as a cultivated crop to Israel, spores of the truffle, obtained from fruit-bodies procured in Italy and France, were used to inoculate oak seedlings and hazel sucker s. Typical T. melanosporum mycorrhizas were observed 3 months after inocula tion on roots of both plant species. One- to two-year-old mycorrhizal seedl ings were outplanted at a number of experimental sites and irrigated regula rly. Two sites characterized by alkaline soil but differing in soil composi tion and climatic conditions were chosen for the present study. DNA of asco carps used for inoculation, DNA of re-isolated cultures and fungal DNA take n from tree mycorrhizas 4 years after outplanting were compared with T. mel anosporum reference cultures by molecular methods. All T. melanosporum prof iles proved to be identical except for one belonging to a reference culture , which exhibited an unusual HinfI ITS-RFLP pattern. A single base substitu tion, responsible for the different HinfI restriction site, distinguished t he ITS region of this culture from a published T. melanosporum ITS sequence . ITS restriction polymorphism analyses determined that roots of all potted plants tested and many 4-year-old trees from the two experimental plots (i rrespective of soil and climatic differences) were colonized by T. melanosp orum.