Symbiosis Effect of Three Micorhizal Fungi (Glumos spp.) on Growth and the Absorption of Some Nutrient Elements in Rooted Cuttings of Three Olive Cultivars

Background and Objectives Olive (Olea europaea L.) trees are traditionally grown in relatively infertile lands being adapted to poor soils and irrigation. New olive orchards are usually established using mist-propagated plants derived from semi-hardwood cuttings. Although this propagation system is very efficient, from the economic point of view, shortening the juvenile period of plantlets is very important. Root colonization with mycorrhizal fungi can shorten the length of the juvenile period in olive plantlets, as inoculated plants can absorb the essential nutrient elements much better resulting in growth enhancement and faster development.
Materials and Methods In this study, symbiosis effect of three mycorrhizal fungi on growth, chlorophyll content and the absorption of some nutrient elements in rooted cuttings of three olive (Olea europeae L.) cultivars was investigated. The study was conducted through a factorial experiment based on a completely randomized design with three replications in the Research Greenhouse of the Department of Horticultural Sciences, Bu-Ali Sina University. The first factor included olive cultivars at three levels (Arbekin “R1”, Conservalia “R2” and Moharam “R3”), and the second factor consisted of mycorrhizal fungi inoculation at five levels (G.mosseae.intraradices) “D1”, )G.hoi.mosseae( “D2”, (G.hoi.intraradices) “D3”, (Mixed three species) “D4” and the control (non-­inoculation) (D5).
Results The results showed that almost all measured characteristics were affected by the treatments. The highest symbiosis percentage was observed in R2D2 and the least belonged to D5. Based on the result, symbiotic fungi made a significant increase in some growth indices including the height and diameter of the plants, leaf area and diameter and length of the branch. The inoculation also caused an increase in the fresh and dry weight of the root and aerial parts of the plants compared to the controls. Mycorrhizal fungal inoculation resulted in increasing the total, a and b chlorophyll contents in all treatments. This symbiosis caused a significant increase in the absorption of some nutrient elements such as K, Zn, Fe and P compared to the controls.
Discussion The results of the present study showed that, mycorrhizal fungi colonization enhanced the uptake of essential nutrients by plants, leading to a greater root surface area and biomass. Both the growth and nutrient content of the mycorrhizal fungi colonized olive plants were increased. It seems that mycorrhiza increases the absorption of water and nutrient elements from the soil through the further development that results in increasing leaf photosynthesis and ultimately increasing the plant growth.