ENHANCED GROWTH OF NON-PHOTOSYNTHESIZING TOBACCO MUTANTS IN THE PRESENCE OF A MYCORRHIZAL INOCULUM

The symbiosis between higher plants and arbuscular mycorrhizal fungi ( AMF) is generally thought to improve the mineral nutrition of many pla nts. Moreover, AMF seem to play a role in transferring assimilated car bon between plants. To answer the question whether this carbon transfe r could be sufficient to enhance the growth of non-assimilating plants , tobacco wild-type plants and non-photosynthesizing mutants were cc-c ultivated in the presence and absence of a mycorrhizal inoculum, Newly formed leaves were counted and biomass was determined at the final ha rvest. The mycorrhizal infection was determined in the roots. When the ! mutants were co-cultivated with a wild-type plant in the presence of a mycorrhizal inoculum, leaf number and the shoot biomass were signif icantly higher than in etiolated plants co-cultivated with wildtype pl ants without AMF or with etiolated plants alone.