تأثير ميكوريزا بر جذب فسفر و خصوصيات رشد ارقام مختلف آفتابگردان (Heliantus annus L)

Effect of Arbuscular Mycorrhizal Fungi on Phosphorus Uptake and Growth Characteristics of Sunflower (Heliantus annuus L.)

Vesicular arbuscular mycorrhiza fungi {Glomus interaradices) can live symbiotically with agricultural plant, roots and through nutrients uptake can increase growth of plants. In order to investigation the effect of mycorrhiza fungi on phosphorus uptake, morphological characteristics and growth indices in sunflower, a 2*2 factorial experiment based on completely randomized blocks design with 3 replications was performed in 2008 at Research Farm of College of Agriculture, Islamic Azad University, Saveh Branch. The factors were two levels of mycorizal treatment (with and without mycorrhiza fungi inoculation) and two sunflower cultivars (Blizar and Progress). The result of this study showed that mycorrhiza fungi increased phosphorus uptake in inoculated plants significantly as compared to non inoculated plants. Characteristics like shoot height, dry shoot weight, root length, dry root weight, leaf area and dry leaf weight in inoculated plants were significantly more than no inoculated plants. Growth indices, including crop growth rate (CGR), relative growth rate (RGR), leaf area index (LAI), leaf area rate (LAR) and specific leaf area (SLA), were higher in inoculated plants than non inoculated ones. Net assimilation rate (NAR) and specific leaf weight (SLW), on the other hand, became smaller in inoculated plants than non inoculated plants.