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Abstract: A split-root experiment investigated the effects of inoculation with the arbuscular mycorrhizal fungus Glomus mosseae and arsenic (As) addition on As uptake by Pteris vittata L. Either part or all of the root system was inoculated with G. mosseae or exposed to As addition (50ml 1000μmolL−1 As 1 week before harvest). Mycorrhizal colonization substantially increased frond and root dry weight and P and As contents irrespective of As addition. Frond As contents in mycorrhizal plants were highest when the whole root system was exposed to As. Frond As concentrations and contents were higher when inoculation and As addition were in the same parts of the root system than when spatially separate. There were positive effects of arbuscular mycorrhiza inoculation on plant growth and As uptake, and inoculation of part of the roots seemed to be as effective as inoculation of the whole root system. [Copyright &y& Elsevier]

A pot experiment was carried out to investigate the tolerance of cucumber plants (Cucumis sativus L.) to root-knot nematode after inoculation with Glomus intraradices. Plants were inoculated with G. intraradices for four weeks and then transplanted in soil treated with Meloidogyne incognita for a further five weeks. The low phosphorus (P) loamy soil was amended with 50 and 100 mg P kg-1 soil. Mycorrhizal colonization increased shoot dry weight, shoot length, leaf numbers, root fresh weight and shoot P concentration, whereas nematode penetration and reproduction were significantly decreased. Similarly, P fertilization usually increased shoot growth and significantly decreased the number of galls and the number of egg masses and eggs per g root. Our results indicate that inoculation with G. intraradices and P fertilizer confer tolerance of cucumber plants to M. incognita by enhancing plant growth and by suppressing reproduction and/or galling of nematodes during the early stages of plant growth. [ABSTRACT FROM AUTHOR]

A pot experiment was conducted out to investigate the yield and pungency of spring onion ( Allium fistulosum L.) as affected by inoculation with arbuscular mycorrhizal (AM) fungi and addition of nitrogen (N) and sulfur (S) fertilizers. Plants were inoculated with either Glomus mosseae or Glomus intraradices or grown as uninoculated controls. Two levels of N and S were applied to the soil in factorial combinations of 50 and 250 mg N kg -1 soil and 0 and 60 mg S kg -1 soil. Plants were grown in a greenhouse for 25 weeks and then harvested. Mycorrhizal colonization resulted in increased shoot dry weight, shoot-to-root ratio, shoot length, sheath diameter, and phosphorus (P) concentrations. Shoot dry-matter yield was significantly affected by added N, but not by S. Shoot dry weight increased with increasing N supply (except for non-mycorrhizal controls without additional S fertilizer). Shoot total S concentration (TSC), enzyme-produced pyruvate (EPY), and organic sulfur concentration (OSC) in plants inoculated with Glomus mosseae were significantly lower than those of non-mycorrhizal controls, while these parameters in plants inoculated with Glomus intraradices were comparable to or higher than in the controls. Neither N nor S supply affected shoot EPY or OSC, whereas shoot TSC (except in plants inoculated with Glomus mosseae ) and SO 4 2- concentrations were usually significantly increased by S supply. In soil of high S and low P availability, mycorrhizal colonization had a profound influence on both the yield and the pungency of spring onion. [ABSTRACT FROM AUTHOR]

A glasshouse pot experiment was conducted to investigate the impact of inoculation of cucumber at the germination stage with Glomus etunicatum BEG168 on plant yield and incidence of Fusarium oxysporum f.sp. cucumerinum inoculated 28 days after the start of the experiment. Inoculation with the AM fungus decreased both disease incidence and disease index. Mycorrhizal inoculation also increased P concentrations in the cucumber seedlings. The mycorrhizal seedlings had higher concentrations of proline and polyphenol oxidase activity but lower malondialdehyde than non-mycorrhizal seedlings, indicating that AM inoculation may have protected membrane permeability and reduced the extent of the damage caused by F. oxysporum . The results indicate that the mycorrhizal fungus may influence plant secondary metabolites and increase resistance to wilt disease in cucumber seedlings and may therefore have some potential as a biological control agent. [ABSTRACT FROM AUTHOR]

The mechanistic understanding of the dynamic processes linking nutrient acquisition and biomass production of competing individuals can be instructive in optimizing intercropping systems. Here, we examine the effect of inoculation with Funneliformis mosseae on competitive dynamics between wheat and faba bean. Wheat is less responsive to mycorrhizal inoculation. Both inoculated and uninoculated wheat attained the maximum instantaneous N and P capture approximately five days before it attained the maximum instantaneous biomass production, indicating that wheat detected the competitor and responded physiologically to resource limitation prior to the biomass response. By contrast, the instantaneous N and P capture by uninoculated faba bean remained low throughout the growth period, and plant growth was not significantly affected by competing wheat. However, inoculation substantially enhanced biomass production and N and P acquisition of faba bean. The exudation of citrate and malate acids and acid phosphatase activity were greater in mycorrhizal than in uninoculated faba bean, and rhizosphere pH tended to decrease. We conclude that under N and P limiting conditions, temporal separation of N and P acquisition by competing plant species and enhancement of complementary resource use in the presence of AMF might be attributable to the competitive co-existence of faba bean and wheat. [ABSTRACT FROM AUTHOR]

Abstract: Development of reclaimed desert soils using intercropping systems and inoculation with rhizobia is a potentially important strategy for utilizing phosphorus-deficient soils and extending the arable land area. Two years of field experiments with different rates of P fertilizer (0 and 120kgP2O5 ha−1 in 2008 and 0, 60, and 120kgP2O5 ha−1 in 2009) were carried out to study the influence of fertilizer P application on the productivity and phosphorus utilization of a Rhizobium-inoculated maize (Zea mays L.)/faba bean (Vicia faba L.) intercropping system in the reclaimed desert soil. Average grain yields of intercropped faba bean and maize increased by 30–197% and 0–31%, respectively (and increased more with zero fertilizer P application) compared with sole crops. Intercropped faba bean showed higher root nodulation and P accumulation but little response to P application regardless of cropping system. The apparent P recovery of the intercropping system was 297.0% greater (P <0.001) than that of sole cropping systems (weighted means) and was highest at the intermediate P application rate on average. Moderate fertilizer P application enhanced productivity and nodulation of the intercropping system in a reclaimed desert soil and P deficiency was ameliorated to some extent. The results indicate that Rhizobium-inoculated maize/faba bean intercropping may be an efficient cropping system for reclaimed desert soils. [Copyright &y& Elsevier]