Nitrogen assimilation , yield productivity and quality in mycorrhized tomato plants

The effects of root colonization by arbuscular mycorrhizal (AM) of mix fungus Glomus mosseae and Glomus intraradices, on nitrogen metabolism, fruit yield and environmental sustainability were studied in field-grown tomato plants by drip irrigation and exposed to limiting P soil content 5 µg/gDW (basal soil) with nitrate fertilization (40 µg/ gDW), after greenhouse germination. At 140 days after sowing, in the harvesting fruit stage mycorrhizal plants (M) had significantly higher mineral nutrient, organic nitrogen and phosphate compounds in both roots and leaves compared to no mycorrhizal plants (NM). In this contest the enzyme activity as NR and GS involved in nitrogen metabolism was tested in root as in leaf. AM inoculation also significantly increased growth and productivity parameters. The fruit yields of M plants were higher than NM plants by 40% and containing significantly higher quantities of licopene, carotene, mineral nutrients and total amino acids. , than NM plants, suggesting that mycorrhizal colonization affects host plant nutritional status, and growth under P limitant field conditions and modified reproductive behaviour, fruit production and quality. We thank the University of Molise and the Microspore S.p.A. for their support.