Frequency of arbuscular mycorrhizal fungi in the rhizosphere of soybean roots and possibility of the mass reproduction of spores.

Arbuscular mycorrhizal fungi coexist with most land plants and these funguses are able to increase the absorption of sedentary nutrients, especially phosphorus, Zn and Cu. Therefore, in this experiment, arbuscular mycorrhizal fungi spore isolation is done through 15 fields of soybean in Golestan province by wet sieve method. The results of this study showed that in all soils studied, there is the potential infection of soybean roots by indigenous mycorrhiza fungi. For further study of the isolated spores, monospore and mass culture were done. Genuses of the collected samples (Glomus, Gigaspora and Scutellospora) were identified. For each gram of soil, respectively, the maximum and minimum number of spores was observed in Azadshahr (284) and Walsh abad-Gorgan (44). Minimum and maximum root colonization percentage was observed, respectively, 20 and 75% in soybean roots and 10% and 85% of sorghum roots in the culture mass.The results indicate that among all the sampling points, in the spores isolated from soil and root colonization percentage of soybean roots were significant at the 1% level. But there was no significant correlation between them.