Effects of mycorrhization and phosphorus nutrition on nutrient uptake, growth and flowering of China aster (Callistephus chinensis (L.) Nees) cultivated on ebb-and-flow benches

Joanna Nowak

doi:10.5586/aa.2009.009

Abstract

The effects were investigated of phosphorus nutrition and AMF inoculation on nutritional status, growth, and flowering of China aster (Callistephus chinensis (L.) Nees) 'Milady' during cultivation on ebb-and-flow benches. Two P treatments of 8.68 and 43.40 mg × dm-3 were applied. One month after inoculation the roots of inoculated plants were infected by mycorrhizal fungi. The control plants had no root infection. The mycorrhizal fungal colonization in plants that were fertilized at 8.68 and 43.40 mg × dm-3 P was 67% and 60%, respectively. Slightly increased P content was detected in leaves of mycorrhizal plants grown under low P level. Mycorrhization did not affect leaf P content of plants grown in high P level. Increased Mg content was measured in leaves of mycorrhizal plants grown under both P levels. Mycorrhizal and nonmycorrhizal plants did not differ with regard to leaf N, K, and Ca contents. P nutrition did not also affect the contents of these elements in leaf tissue. Mycorrhization decreased the pH and lowered salt accumulation in growing media. Significantly lower shoot biomass, plant height, shoot number were recorded in all plants inoculated with AMF. Mycorrhization also delayed flowering of China aster; the high P level slightly accelerated it. Mycorrhizal plants had fewer flower buds and flowers than nonmycorrhizal ones. The high P level increased the number of flowers of nonmycorrhizal plants only.

Highlights

Bedding plants cultivated in greenhouses are often grown in disinfected substrates to lower risk of contamination
Inoculation with arbuscular mycorrhizal fungi (AMF) during cultivation in greenhouses may be beneficial for further plant growth in outdoor conditions
Many studies have shown that mycorrhizal plants have higher shoot P concentrations than plants with no or reduced AMF colonization when these plants are grown in soils with low P content

Summary

Introduction

Bedding plants cultivated in greenhouses are often grown in disinfected substrates to lower risk of contamination. Disinfection treatment eliminates arbuscular mycorrhizal fungi (AMF) in growing medium. The mycorrhizal inoculation has the potential to enhance growth and flowering of ornamental plants, in nutrient-deficient soils (G a u r and Adholeya, 2005) or in drought conditions (A u g z , 2000). Inoculation with AMF during cultivation in greenhouses may be beneficial for further plant growth in outdoor conditions. It was shown earlier that mycorrhization of some bedding plants is significantly reduced by high P concentration (Koide et al 1999). Plant growth responses to AM fungi are found to vary with the host plant and soil (Entry et al 2002)

Methods

Results

Conclusion