IRON ACQUISITION BY MYCORRHIZAL MAIZE GROWN ON ALKALINE SOIL

Vesicular-arbuscular mycorrhizal fungi (VAMF) we known to improve the mineral nutritional status of plants. Since information on effects of VAMF on plant iron (Fe) nutrition is limited, an Fe deficient-suscepti ble maize (Zea mays L., ys1/ys1) was grown on alkaline Quinlan (Typic Ustochrept, pH 8.0) and Ulysses (Aridic Haplustoll, pH 7.8) soils with Glomus VAMF isolates G. etunicatum WV579A (Gel, G. diaphanum WV579B ( Gd), and G. intraradices WV894 (Gi) to determine plant growth response s to VAMF associations and efficacy of these VAMF isolates to enhance Fe acquisition. Shoot and root dry matter (DM) were higher in mycorrhi zal (+VAM) then in nonmycorrhizal (-VAM) plants, and followed a sequen ce of Ge > Gd greater than or equal to Gi > -VAM. Root DM of Ge plants was higher than other +VAM plants. Even though relatively low, leaf c hlorophyll (SFAD unit) readings were higher in +VAM than in -VAM plant s and followed a sequence similar to DM. Plants colonized with Gi had higher leaf Fe, phosphorus (P), and zinc (Zn) concentrations and conte nts than other +VAM as well as -VAM plants. Leaf concentrations and co ntents of other mineral nutrients had few changes among +VAM plants, b ut some differences between -VAM and +VAM plants were noted. The VAMF isolates improved Fe acquisition in maize grown under severe Fe defici ency conditions, but benefits to this fast growing plant was not suffi ciently large to recommend that it be grown on fields where Fe deficie ncy is prevalent. improved host plant root development. and morphology and acquisition of P may have been involved in enhanced Fe acquisitio n by +VAM plants.