Portal de Periódicos da CAPES

Interactions between phosphorus supply and total nutrient availability on mycorrhizal colonization, growth and photosynthesis of cucumber

2001; Elsevier BV; Volume: 88; Issue: 3 Linguagem: Inglês

10.1016/s0304-4238(00)00205-3

1879-1018

Alex J. Valentine, Bruce Osborne, D. T. Mitchell,

Plant nutrient uptake and metabolism

The effects of arbuscular mycorrhizal (AM) infection by Glomus mosseae (Nicolson & Gerdemann) Gerdemann & Trappe on growth, photosynthesis and nutrient concentration of cucumber (Cucumis sativus L. var. Telegraph Improved) were studied in sand culture with three different nutrient solutions based on the Long Ashton formula. These were high P+high concentrations of the other essential nutrients (full-strength solution containing 1.3 mM P), low P(0.13mM)+high concentrations of the other nutrients and low P+low concentrations of the other nutrients (10% of the full-strength nutrient solution). AM infection was found to depend on both P supply and the availability of other nutrients. Plants grown at low P with high concentrations of other nutrients had the highest AM infection, and a higher biomass due to an enhanced maximum net photosynthetic rate (Pm). Although this was unrelated to the N concentration of leaves, there was evidence that the higher Pm was associated with a low leaf P concentration and the significance of these results is discussed. With high P and high concentrations of the other nutrients, a growth depression was found with +AM plants, although this was not due to a reduction in photosynthesis or an increase in leaf dark respiration rate. It was, however, associated with a reduction in photosynthetic nitrogen use efficiency. Overall, the present study indicates that any advantages or disadvantages associated with AM infection in cucumber are a result of complex interactions between P supply and the availability of other essential nutrients.