معرفی سیزده گونه سیاهک‌ از جنوب غربی ایران

Smuts (Basidiomycota, Ustilaginomycotina) are obligate plants parasitic fungi, that produce a black powdery mass of teliospores on the aerial parts of plants and cause a severe loss in quantity and quality of their yields. Kohgiluyeh and Boyer-Ahmad province, southwest of Iran, with diverse climates, is an important region in the production of agricultural products. Fields of Boyar-Ahmad, Dena, Gachsaran and Kohgiluyeh regions were visited in spring and summer and the plants infected with smut fungi sampled. The characteristics of the shape and color of the teliospores mass, their placement on different organs of the host, and whether the teliospores mass are visible or covered, and the shape, dimensions, color, and surface decorations of the teliospores were studied and measured, after preparing microscopic slides of them with a calibrated bright field microscope Olympus model CX11, equipped with a scaled eyepiece. The collected data were compared with the original descriptions of smut fungi and 13 species belonging to the four genera Ustilago, Sporisorium, Tilletia and Urocystis , with the names:Ustilago avenae, Ustilago cynodontis, Ustilago hordei, Ustilago hypodytes, Ustilago maydis, Ustilago tritici, Ustilago trebouxii, Urocystis agropyri, Tilletia caries, Tilletia laevis, Tilletia indica, Sporisorium cruentum, Sporisorium reilianaum , respectively on oat, common coach, barley, Agropyrum repense, corn, wheat, Bromus sp., Agropyron sp., wheat, wheat, Sorghum halepense , and sorghum, were identified. Among these fungi, Tilletia indica, the cause of wheat partial (Karnal) bunt, is reported for the first time from this province. The phylogenetic relationship of eight species of these fungi was studied by sequencing their ITS regions (5.8S rDNA gene) with ITS1 and ITS4 primer pairs, which shows the high similarity of U.cynodontis with U.maydis, and U. hordei with S. cruentum and U. agropyri.