Effect of Endophytic Fungi Pirifomospora indica on Flowering and Root Growth Parameters of Strawberry in Hydroponic Culture

Strawberry as an herbaceous perennial plant, belongs to the Rosaceae family, which is considered as an important plant, due to having various types of vitamins such as C, A, B6, E. Nowadays, the excessive use of chemical fertilizers instrawberry productionin order to increase yields, has resulted in environmental pollution and dangers on the health of consumers. Microbial endophytes are considered as the most important soil microorganisms with genetic, physiological and ecological impacts in their host plants, increasing the yield. Pirifomosporaindica is a member of Basidiomycetes in order Sebacinales.The fungus is easily cultivable, lacks host specificity and colonizes roots of many different plants, mostly in an endophytic fashion. It interacts with a wide range of hosts, including bryophytes, pteridophytes, gymnosperms and a large number of mono- and dicot plants. The fungus grows inter- and intracellularly, forms pearshaped, auto fluorescent chlamydospores within the cortex of the colonized roots and in the rhizosphere zone, but it does not invade the endodermis and the aerial parts of the plants. The fungus promotes nutrient uptake, allows plants to survive under water, temperature and salt stresses, and confers systemic resistance to toxins, heavy metal ions, insects and pathogenic organisms. In this study,the effectson the flowering and root growth parameters of strawberry in hydroponic culture was examined in a completely randomized design with 28 replicationsundergreenhouse condition of Faculty of Agriculture,TarbiatModarres University. This research was conducted in the greenhouse of faculty of agriculture TarbiatModarres University.Fungi used in this study was prepared of fungi collection of the Department of Pathology, University of TarbiatModarres. Endophytic fungus roots was cultured in solid medium Kafer.For this study, 140 strawberry runners were prepared and then put them in a pots with diameter of 25 and height of 30 cm was cultivated in perlite and cocopeat.Two weeks afterestablishment roots, concentrations, 0 (control), 80, 160, 250 and 330 spores/ml of endophytic fungus P. indica was inoculated by injecting around roots of strawberry plants. Temperature and humidity conditions needed for fungal growth were provided in the strawberry’s greenhouse and were irrigated with a nutrient solution three times per day. Eight month after fungal inoculation flowering content was measured for all pots. One week after the last harvest length, Fresh and dry weight roots were measured. Data is transferred to excel software and then analyzed using SAS 9.1 software and comparison of means using Duncan test was conducted. Analysis of variance showed that among treatments there is significant difference on growth parameters of strawberryplants (P < 0.01),soby increasing concentration of fungi increased growth parameters and this indicate the positive impact of the endophytic fungus onthe growth parameters of strawberry plant is inoculated with the fungus than the control plants. Results showed that the maximum and minimum effects of fungal on growth parameters related to 330 sp/ml and control treatments, respectively. flowering content showed 37 and 18.53 percent increase respectively under 330 and 250 spores/ml compared to control which can be related to absorb more nutrient elements, especially phosphorus and biomass of strawberry plants. Root dry (76.71 and 52 percent) and fresh (75.52 and 40 percent) weights were increased under 330 and 250 spores/ml treatment compared to control and were significantly different with other treatments (P < 0.05), while there was no significant difference among control, 80 and 160 spores/ml treatments. Regarding to root length, 330, 250 and 160 spores/ml treatments resulted in 72, 37 and 14.33 percent increase respectively compared to control and showed a significant difference with other treatments. In this respect, it can be stated that P. indica at high concentrations due to the increase production of auxin that increased the root length, root dry and fresh weight is inoculated plants compared to control that increase root growth parameters which cause absorb more nutrient elements from soil. It can be concluded that high concentrations of the fungus P. indica can increase physiological characteristics (the flowering, root length and dry weight and fresh weight) of strawberry plants. and thus it has a positive effect on plant growth and yield.