Responses of maize to mycorrhizal colonization under varying intensities of zinc stress

摘要

Greenhouse experiment was conducted in order to study the responses of hybrid maize to mycorrhizal colonization under varying intensities of zinc (Zn) stress conditions. Treatments consisted of five levels of Zn (0, 2. 5, 0, 2. 5, 5.0, 7. 5 and 10. 0 kg/ha) and two mycorrhizal treatments (with or without inoculum carrying Glormus intraradices ) replicated thrice in factorial RBD. Growth measurements in leaves and roots were determined after the establishment of functional symbiosis (45 days after sowing). The results revealed that mycorrhizal colonization significantly increased the leaf area index regardless of varying levels of Zn be sides enhancing the chlorophyll contents of leaves. Root proliferation (weight, volume, length and root spread) in mycorrhizal maize plants were higher by 25%-35% than non-mycorrhizal plants irrespective of levels of Zn. The mycorrhizal response was more pronounced in roots than shoots. Overall data suggest that mycorrhizal colonization modified the root architecture which fa-voured uptake of immobile micronutfients such as Zn. This process helped the mycorrhizal plants to retain higher amounts of chlorophyll and leaf area index even under Zn deficient conditions.