Abstracts |
A pot experiment was conducted in Egypt to investigate the effects of inoculation with vesicular arbuscular mycorrhiza (VAM; Glomus fasciculatum) on wheat cv. Giza-164 growth, P uptake, water relations, chemical constituents and grain yield. Wheat plants were grown under 3 levels of water regime (40, 70 and 100% field capacity) and 2 P sources: rock at 1 g and mineral phosphate at 100 mg/kg soil (P1 and P2). Half of the pots were inoculated with VAM. Inoculation with VAM significantly increased shoot and root lengths, dry weight and leaf area under different levels of water stress. A highly significant increased in these parameters were found by interaction of P and VAM inoculation under different levels of water stress. VAM inoculation and P treatment significantly decreased stomatal conductance under drought stress. VAM inoculation showed highly significant reduction in transpiration rate. VAM-treated plants recorded higher relative water content especially with P-treatment. High reductions in leaf water potential, osmotic potential and maintenance highly turgor potential in wheat leaves were observed under water stress condition. VAM inoculation recorded highly significant induction in chemical constituents, e.g. chlorophyll a, b, total chlorophyll, N, P and K uptakes, total sugars, total amino acids, as well as proline concentration, especially with P addition under water stress, which increased the osmoregulation of wheat plants under water stress. VAM highly significantly affected the maintenance of cytokinin concentration especially under drought stress than uninoculated plants. The same trend was observed in increasing straw and grain yields per pot, and 1000-grain weight. Root infection percentage with VAM decreased insignificantly with increasing drought stress and decreased significantly under P-treatment; P1 was more effective in increasing root infection percentage than P2. VAM inoculation had higly significant effect in reducing the harmfull effects of water stress by maintaining turgidity, may be by increasing root density or by regulating osmotic adjustment of wheat plants.. |