نشریه رستنیها
سال دوازدهم شماره 1 (پیاپی 40، بهار و تابستان 1390)

Black yeast fungi play critical role in degradation of petroleum polluted soils. Little attention has been paid to the biodiversity of black yeast fungi in Iran. In this paper، diversity of black yeast fungi was studied in petroleum polluted soils in Tabriz and Urmia regions. Soil samples were collected from petroleum polluted areas in vicinity of oil storage tanks in Tabriz and Urmia cities (East and West Azarbaijan provinces) in summer 2009. Isolation was carried out by using «floatation in mineral oil» method with minor modifications on Mycosel medium. In total، 38 isolates with melanized colonies were recovered and then purified using repeated streaking method. Fungal isolates were identified based on morphological charactersitics to species level as Exophiala heteromorpha، E. spinirera،E. xenobiotica، Cadophora malorum، Alternaria malorum، Cladosporium cladosporioides and Aureobasidium pullulans; of those Exophiala heteromorpha، E. pinifera،E. xenobiotica، urobasidium pullulans and Cadophora malorum represent new records for mycobiota of Iran and the rest are new reports from petroleum polluted soils in Iran.

For studying vegetation cover in Choghakhor wetland located in Chaharmahal-o-Bakhtiari province (W Iran)، some zones of vegetation life forms were determined and also digitized in order to produce the primary map of plant cover by using LISS-IV sensor of IRS satellite with the spatial resolution of 5. 8 m. As aquatic plants in Choghakhor wetland were fully grown، homogeneity or heterogeneity of vegetation units and their zones were measured based on quantitative characteristics of plants communities. Vegetation sites were evaluated from shore to water body by linear transects and sampled quantitative characteristics in 1 × 1 m quadrates at 10 and 20 m intervals. Frequency Presence Diagram was used in order to recognizing of zoning and horizontal array of wetland plants. Summing of species array based on water depth and dominated plant types were shown that wetland vegetation cover is distinguished to two main zones and one transitional zone. The result of this study indicates that the first zone dominates with emergent plants and continues from wetland shore to 0. 5 m depth of water. Transitional zone locates in the depth of 0. 5–1. 0 m. Last zone (from depth of 1–2 m) is in dominance of submerged plants.

The Family Russulaceae comprises of some important agaricoid and gasteroid taxa of Agaricomycetes. Two genera، Lactarius and Russula are distinctive basidiomycetes that possesses heteromerous tissue composed of sphaerocyte cells and amyloid ornamentation on their basidiospores. Some of the important ectomycorrhizal، edible، poisonous and medicinal species have been rested in genera Lactarius and Russula. In this paper، seven species of the fungi belonging to genera Lactarius and Russula (Russulales، Russulaceae)، collected from Arasbaran forests، were identified. Three species، L. serifluus، R. lilacea and R. sororia are reported for the first time for Iranian mycoflora. All species، are re-described and illustrated with photographs and drawings.

In this study، 10 species of Bipolaris viz. B. bicolor، B. cynodontis، B. cylindrica، B. hawaiiensis، B. prieskaensis، B. sorghicola، B. sorokiniana، B. spicifera، B. zeae and B. zeicola and four species of Curvularia viz. C. fallax، C. heteropogonicola، C. inaequalis and C. lunata were identified on graminicolous species or soil. Bipolaris cylindrica، B. prieskaensis، B. zeae، C. fallax and C. heteropogonicola are newly reported from Iran. Some new host plants are reported for above-mentioned fungal species.

Fifteen populations of Pimpinellifoliaeae section from the species; Rosa pimpinellifolia، R. hemispherica، R. foetida and a new species، R. abrica، were collected from eight provinces of Iran and were studied on the basis of their morphological characters. In each population five plants were randomly selected and some branches were harvested in spring and autumn for studying their vegetative and floral characteristics. Sixty-three qualitative and quantitative characters were grouped using the most suitable method of cluster analysis (WARD) and their ordination diagram based on the most variable factors، were written for each species and the section. The results showed that the effect of ecological factors such as altitude influenced the intra-species variation. Cluster analysis illustrated high similarities between R. hemispherica and R. foetida. In the present research two unique populations of a new species (not recorded in K، W، E، G and Iranian herbaria)، named R. abrica، were also analyzed. Culster analysis separated the R. abrica as a different group compared to other species of this section. Traits such as curved prickles، high number of petals، truncate or seldom emarginated petals، indeterminate state of achenes and stigma were significant in classification of the new rose species. Although، R. abrica is very similar to R. foetida but in characters such as number of leaflets، corymbs inflorescence، entire edge of sepal or seldom with lobes، hairy style، glabrous hips and pedicels، it is significantly different from R. foetida.

Several leaf spotting or blotching fungal diseases occur on forest trees in Guilan province (N Iran). Some of them such as maple tar spot affect health of host trees severely، but many are of minor effect. This study was carried out to identify unknown and less known fungi causing leaf spot and leaf blotch diseases on broad leaf trees in this region. So far numerous fungi were collected. Four species viz. Sphaeropsis mespili (on Mespilus germanica)، Seiridium unicorne (on Crataegus melanocarpa)، Septoria cornina (on Cornus sanguinea) and Tubakia dryina (on Quercus castaneaefolia) and two unidentified species belonging to Cylindrogloeum sp. (on Fraxinus excelsior) and Monostichella sp. (on Corylus avellana) are recorded for the first time from Iran. Furthermore، Phloeospora aceris (on Acer cappadocicum) and Marssonina juglandis (on Pterocarya fraxinifolia) are new members to Guilan mycobiota.

Munjughlu sanctuary zone with 5270 hectares in East Azarbaijan province is one of three sanctuary zones in the Marakan protected area. During 2008–2009، 236 taxa (23 subspecies، 22 varieties and one form) belonging to 166 genera and 38 families were collected and determined for this zone. Among them، 208 taxa are dicots and 28 are monocots. Family Compositae with 46 species and Cruciferae with 23 species are the largest families followed by Amaranthaceae with 21 species and Poaceae with 16 species. The most diverse genera are Astragalus and Centaurea. This area contains 14 endemic taxa، seven rare taxa and five monotypic genera. For the first time، 21 taxa from Northwest Iran and 14 taxa from East Azarbaijan and a single taxon from East and West Azarbaijan are reported here. Dominant life forms include therophytes (40%)، followed by hemicryptophytes (31. 92%). The chorological study shows that bi- tri- or plural elements with 58. 95% of the chorotypes are dominant، followed by Irano-turanian elements with 39/77%.

Different species of Trichoderma especially T. harzianum (Th2 biotype in Europe and Th4 in America) considered as causal agent of green mould disease on button mushroom (Agaricus bisporus) casing beds. In this study، 100 fungal isolates were collected and purified from different mushroom growing units in Tehran province and Urmia (NW Iran). Totally، 60 isolates of T. harzianum، 27 isolates of T. virens، seven isolates of T. hamatum and six isolates of T. inhamatum were morphologically identified. The main infectious agent was T. harzianum. Specific primers were used for identification of different biotypes. Th2 and Th4 biotypes specific primers amplified 450bp fragment. Using these primers، 30 isolates of Th2 and Th4 biotypes called T. aggressivum f. aggressivum and T. aggressivum f. europeaum were identified from 60 isolates of T. harzianum. Colony growing rates of 60 fungal isolates were measured at 15، 20، 25، 30 and 35º C for determination of optimum growth temperature. These optimum temperatures for Tehran and Urmia isolates were 30º C and 22±2º C، respectively.