Rostaniha
Year:2009 | Volume:10 | Issue:2 (36)|Papers Count:10

Walnut anthracnose caused by Ophiognomonia leptostyla is the most important and prevalent fungal disease in most walnut growing areas in Iran. Seventy-five isolates of Ophiognomonia leptostyla, causing walnut anthracnose, were obtained from Juglans regia from various regions of Iran. In order to study the sexual reproduction of the fungus, the isolates collected from various parts of Iran were examined and perithecia were obtained from 11 regions from leaves and in eight isolates from oatmeal agar (OA). These isolates along with five sexually nonfertile isolates were purified as single-ascospore or single-macroconidium cultures. Protoperithecia were readily obtained from leaves collected more than one year back. Perithecia had one beak on leaves and up to four beaks on culture media. As the result 9.3% of isolates were found to be homothallic. In dual cultures of seven non-homothallic, but sexually fertile in vivo, and five sexually non-fertile isolates, no fertile perithecium was produced. Perithecium in homothallic isolates had significantly higher diameter and longer beaks than non-homothallic isolates. There was no significant difference between homothallic and non-homothallic isolates in ascus and ascospore size, colony growth rate and disease index.

An investigation was carried out in some areas of Golestan Province including: Loveh forest, Soosara, Daland forest park, Tooskestan; Gilan Province including Siahkal and Asalem forests; Arasbaran and landscape of urban trees during 1999–2007. In this investigation, based on some morphological, physiological and molecular characteristics and also comparison with standard isolates two species Ophiostoma ulmi and O. novo-ulmi were identified as casual agents of Dutch elm disease where majority of isolates belonged to O. novo-ulmi. This is the first report of O. novo-ulmi on Ulmus glabra and U. carpinifolia, from Tooskestan forest and urban elm trees and here it is compared with O. ulmi. The O. novo-ulmi isolates of Iran belonged to the EAN (Euro-Asian) populations based on sequence comparison.

Arasbaran is one of the most important protected regions in Iran located in NW of the country and east of E Azarbaijan Province. Several reports have been published on the mycobiota of this region however there is only few records about rust fungi of Arasbaran. Our research on rust fungi of Arasbaran region gets started since 2006. During this study, several rust taxa collected and identified from this area. Among identified taxa, Puccinia jaceae on Centaurea macrocephala, P. chaerophylli var. retifera on Chaerophyllum aureum, Uromyces prosopidis on Prosopis farcta var. farcta and Uromyces heliotropii on Heliotropium europaeum are newly reported from Iran. Several new hosts for identified rust taxa are also reported.

Ranunculus L. with about 600 species is the largest genus in the Ranunculaceae. Problems in the taxonomy of the genus are due to high variability and polymorphism among different individuals and populations of certain species. Morphological characters of nectar scale have been considered as valuable taxonomical characters in some perennial species in some groups (Praemorsa, Grumosa, Rhizomatosa). To find out significant differences in characters among populations of certain species and among different species Analysis of Variance (ANOVA) was performed. In this study, herbarium specimens or fresh material were studied. Different shapes of nectar scale have been observed among populations of some species that is related to karyotype variability.

Five species of clitocyboid fungi belonging to genus Clitocybe viz. C. geotropa, C. houghtonii, C. infundibuliformis, C. rufuloalutacea and C. trulliformis are reported from Iranian part of Caucasia. The reported fungi are new records for Iran.

Silene is represented by c. 110 species in flora of Iran which growing mainly in the mountainous areas. During several expeditions to different regions of Iran (Tehran, Semnan, Kerman, Kermanshah and Kohgiluyeh va Boyer-Ahmad Provinces) some interesting specimens were collected. S. caucasica, is introduced as a new record for the flora of Iran. Five interesting and very restricted Iranian endemic species including S. sojakii, S. nizvana, S. dschuparensis, S. daenensis and S. hirticalyx are rediscovered from locus classicus after single record of type specimens. The descriptions of these species are improved and their photographs, habitats, geographical distributions are presented.

In order to investigate light and temperature effects on germination of different ecotypes of wild mustard (Sinapis arvensis L.), seeds were collected from four regions: Fars, West Azarbayjan, Khouzestan and Mazandaran Provinces. Seed size and weight, difference of dormancy state among the ecotypes, seed germination in differential light and temperature conditions were studied. The results showed that seeds from different locations did not have the same size, but they were similar in weight. The seeds had some differences in germination but there was not correlation between germination and seed size. The range of temperature for germination was between 5 to 35°C in all ecotypes. The germination rate in Khouzestan ecotype was higher than those of the other locations. Although germination was promoted by light under high temperature (more than 20°C), there were different rates among the ecotypes under low temperatures. Results showed that environmental maternal conditions effect on seed germination. Dormancy state of seeds was different among the ecotypes. When the seeds exposed to the same conditions, the ecotypes showed some differences in germination behavior.

The genus Inula L. belongs to tribe Inuleae (Asteraceae) with about 100 species in the world. In this study, leaf in cross section and epidermis in superficial view were studied. Twenty one characters were used for separating the species with an identification key. The most important characters like kind of hairs, shape of epidermal cells on both surfaces, stomata in superficial view and in cross section, number of vascular bundles, rows of palisade parenchyma and aspect of sclerenchyma were used for analyzing with SPSS program. Based on anatomical characters of leaf, nine clusters were recognized: Inula acaulis and I. rhizocephala in the first cluster; I. grantioides in second cluster; I. rajamandii, I. viscidula and I. oculus-christi in third cluster; I. persica and I. britanica in fourth cluster; I. thapsoides and I. vulgaris in fifth cluster; I. helenium in sixth cluster; I. aucheriana in seventh cluster; I. salicina in eighth cluster and I. montbretiana in ninth cluster. These results supported the morphological studies reported before.