INFLUENCE OF GLOMUS-FASCICULATUM ON PHYSIOLOGY AND GROWTH OF 3 KINDS OF MAIZE

Three materials of maize with differ ent levels of genetic improvement were inoculated with the arbuscular mycorrhizal fungi Glomus fascicul atum Gerdeman & Trappe under glasshouse conditions to assess their inf luence on photosynthesis, stomatal conductance, growth, P status and m ycorrhizal infection of roots. Seeds were sown in 2 liter containers w ith a sterilized mixture of sand and sandy loam soil. Long Ashton nutr ient solution (LANS) was utilized to supply P at 22 mu g ml(-1). Diurn al gas exchange measurements were taken 55 days after the experiment w as initiated. Growth, shoot P content and mycorrhizal infection were a ssessed 60 days after sowing. This research supports the hypothesis th at plant breeding in maize decreases the effect of mycorrhizal associa tion. Mycorrhiza enhanced net photosynthesis in the three maize materi als with higher values in non-breeded plants. Stomatal conductance inc reased in inoculated non-improved plants. Symbiosis increased plant si ze, shoot dry weight, leaf dry weight and reproductive effort in the n on-breeded plants, however inoculation was detrimental to leaf number in this. P content was smaller in VAM non-breeded variety, while the m ycorrhization in he intermediate genetic handled one, increased P cont ent. Mycorrhizal colonization was higher in materials with less geneti c handling.