ICOM1 Abstract

DIEZ, JESUS & JOSE L. MANJON. Biolog’a Vegetal, Universidad de Alcala de Henares, 28871 Alcala de Henares, Spain. - In vitro mycorrhization of micropropagated plantlets of Tuberaria guttata with desert truffles, and mycorrhizal persistence after acclimation monitored by PCR. Tuberaria guttata belongs to the Cistaceae and establishes mycorrhizal association with desert truffles. This symbiosis is common in the Western Mediterranean Basin. The mycorrhizal synthesis has been carried out in axenic and gnotoxenic conditions. However, no mycorrhization of micropropagated plantlets of T. guttata has been reported. The main objectives of the present study were to develop the micropropagation and in vitro mycorrhization of T. guttata, and to design tools for monitoring the mycorrhizal status of plantlets. Mycelial cultures of desert truffles were obtained from fruit-body tissues in the Fontana and BAF medium. Micropropagation of T. guttata was carried out by microcutting of shoot tips and nodal segments in MS medium with a low cytokinin concentration. Microcuttings rooted spontaneously, but indole- 3-butyric acid or macronutrient reduction increased rooting percentages. Mycorrhization of micropropagated plantlets was carried out on the Sommer medium with some modifications, and then acclimatized to the greenhouse conditions. Mycorrhizal status was confirmed by PCR/RFLP of the internal transcribed spacer (ITS) of the nuclear rDNA. The present study is the first report of the mycorrhizal inoculation of T. guttata microcuttings.