بررسی قارچ‌های رشته‌ای و مخمرها در خاک مزارع آلوده زعفران با علائم پوسیدگی بنه، تربت حیدریه، ایران

Fungi are one of the most diverse microorganisms in soil. Pathogenic microorganisms in soils can lead to much damage in a wide range of crops by reducing the quantity and quality of the product. Saffron is a native plant in Iran that is obtained from the dried stigmas of Crocus sativus flowers and has many applications in the food and pharmaceutical industries. In this research, Considering the importance of investigating the growth ecosystem of this plant, an abundance of filamentous fungi and yeasts in contaminated soil fields with symptoms of saffron corm rot were studied, to investigate the pathogenicity of them on saffron plant. In this research, five different samples of soil from contaminated saffron fields, which had symptoms of corm rot in the plant, were collected from the Torbat Heydarieh region, Iran, and transported to the laboratory. In the next step, filamentous fungi and yeasts were isolated and purified from samples. Purification of fungi was carried out by the single hyphal tips method and transferred to PDA culture medium, and purification of yeast was carried out by streak method and culturing in YEPDA medium. Then, DNA was extracted from the isolates and their molecular identification was done by PCR reaction method, according to the primers of the ITS region (ITS1-ITS4) for filamentous fungi and the primers of a part of the LSU region (NL1-NL4) for yeasts. In this research, sixteen filamentous fungi and four yeast samples were finally isolated. Their molecular identification showed that filamentous fungi of the genus Penicillium (%43.75), Absidia (%18.75), Mucor (%18.75), Rhizopus (%12.5) and Aspergillus (%6.25) belonged and the yeasts belonged to Candida (%50), Ogataea (%25) and Blastobotrys (%25). The results of this research showed that the abundance of filamentous fungi in terms of numbers and species was more compared to yeasts, in the soil of contaminated saffron fields with symptoms of corm rot in the plant, and among filamentous fungi, Penicillium is more abundant in the contaminated fields. Additional studies and pathogenicity tests can determine which of the isolated filamentous fungi and yeasts would cause corm rot disease and decreased yields in the saffron plant. These data would help experts and farmers set up better strategies for control of this disease.