Selection of arbuscular mycorrhizal fungi species for tomato seedling growth, mycorrhizal dependency and nutrient uptake

Arbuscular mycorrhizae (AM) associations are of great importance in horticultural seedling quality in the Mediterranean region, but information on host dependence and host responsiveness to the fungi species is scarce. Thus, this study was designed to assess the effects of several mycorrhizal fungi species and their cocktail on tomato (Solanum lycopersicon L.) seedling growth, quality and nutrient uptake. Tomatoes were grown in growth medium and inoculated with Glomus (G.) mosseae, G. clarum, G. etuni-catum, G. intraradices, G. caledonium and cocktail of them. The experiments were carried out three successive years from 1999 to 2001. Plants were harvested once in the first year experiment, but in the second and third year experiments plants were harvested twice at different developmental stage. In experiments, non-inoculated, seed inoculation and seedling inoculation were compared. Pre-inoculation and re-inoculation increased growth parameters of tomato seedlings in three years. The in-oculated plants produced significantly higher biomass than those of non-inoculated plants. In general, plants re-inoculated at seedling stage had higher growth performance than seed inoculated plants. However pre-inoculation (seed stage inoculation) have higher mycorrhizal dependency than re-inoculation (seedling stage). All the inoculated plants were extensively colonized by all of the AM fungi species. Inoculated plants flowered earlier than non-inoculated plants. The AM plants generally enhanced content of phosphorus (P) and zinc (Zn) and the G. etunicatum inoculated plants particularly had higher nutrient uptake compared to the other AM plants. Plant response to the mycorrhizal inoculation was different for both inoculation times. There were no specific species showed superiority to others for both inoculation times and three years repetition, however in generally, G. clarum mycorrhiza species gave the highest responses as regarded to measured parameters. © Verlag Eugen Ulmer KG, Stuttgart