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Pythium ornamentatum (IRAN 2589C): a–d. Hyphal swellings, e–f. Antheridia attached to oogonia, g. Hypogynous antheridium and oogonium, h. Plerotic and aplerotic oospores, i. Oogonium with a papilla, j. Oogonium with bifurcated spine (Bars = 10 μm).
Source publication
Pythium is a fungus-like genus with worldwide distribution that is found in most terrestrial and aquatic ecosystems. It is a species-rich genus contains important plant pathogenic species. Little is known on the systematics of Pythium in West Azarbaijan province (N.W. Iran). Thus, the aim of this study was to identify 200 isolates collected from di...
Citations
... This species was first isolated in 1998 by Paul et al. (1998) from a soil sample taken in the Burgundy region in France. In Iran, only one isolate from the soil of an apricot garden in Maku, East Azerbaijan, Iran, had been reported by Badali et al. (2016). Moreover, it seemed that there was no other report from other parts of the world. ...
Pythium and Phytophthora are among the most well-known plant pathogens around the world that cause rotting of seeds, root, and crown, seedling death, and soft rot of fruits in contact with the soil. In this research, 347 isolates of these two genera and their close genus, Phytopythium were isolated from the cucurbits fields in Kermanshah province, Iran and examined in terms of morphological and physiological characteristics. ITS-rDNA region and the partial cytochrome oxidase II (cox II) gene from the selected isolates were amplified and sequenced to confirm the morphological identification. Based on the morphological , morphometrical, physiological, and phylogen-etic examinations, nine species of Pythium including P. aphanidermatum, P. dissotocum, P. catenulatum, P. kashmirense, P. middletonii, P. nodosum, P. oligandrum, P. torulosum, and P. ultimum; two species of Phytopythium including Pp. mercuriale and Pp. litorale, and three species of Phytophthora including Ph. melonis, Ph. nicotianae, and Ph. parasitica were detected. Among the species identified in this study, Pp. mercuriale was a new record for mycobiota of Iran and two species, P. aphanidermatum and P. ultimum were isolated more frequently.
Phytopythium is a cosmopolitan genus found in different regions of the world from various substrates. This genus is a newly described taxon that was once a member of the genus Pythium sensu lato. Phytopythium is an intermediate genus between Pythium and Phytophthora with 34 formally described species. Recently, some studies focused on the phylogeny of this genus in Iran. Although not many studies concentrated on isolating species assigned to this genus from Iran, some comprehensive studies showed that Phytopythium is an important genus with vast distribution in this part of the world. Accurate identification and classification of Phytopythium species are quite challenging. Morphological identification of Phytopythium is troublesome due to the lack of identification keys, overlapping of some morphological features, the presence of species complexes, pleomorphism, and the absence of certain structures in some species. Besides, most species cannot be separated using only one or two loci for the phylogenetic analyses. In addition, some studies in Iran do not include molecular investigations to support their morphological identification or make it possible to reidentify the reported species. Having no accurate and current checklist of the country’s species also adds to the problem. This review focuses on the current systematics of Phytopythium species in Iran, discussing the challenges in the morphological and molecular identification of the species in the country. It also proposes some approaches to address the problem of characterizing the species in the genus Phytopythium
The genus Globisporangium is a newly described taxon that has been recently separated from Pythium sensu lato. Although not many studies focused on isolating species assigned to this genus from Iran, some comprehensive studies showed that Globisporangium is an important genus with vast distribution in this part of the world. Even rare species assigned to Globisporangium have also been found in the country. Despite the importance of this genus, accurate identification and classification of Globisporangium is quite challenging worldwide. Morphological identification of Globisporangium is quite difficult due to the lack of identification keys, overlapping of some morphological features, the existence of species complexes, pleomorphism, and the absence of certain structures in some species. Furthermore, there is no universal DNA barcode for Globisporangium species yet, and most species cannot be delimitated using only one or two loci for the phylogenetic analyses. Besides, some studies in Iran do not include molecular investigations to support their morphological identification or make it possible to reidentify the reported species. Having no accurate checklist of the current species in the country also adds up to the problem. This review focuses on the current systematics of Globisporangium species in Iran, emphasizing the challenges in the morphological and molecular identification of the species in the country; it also proposes and discusses some solutions to resolve these problems.
The symptoms of crown rot on strawberry plants are considered typical for the pathogen Phytophthora cactorum, which causes high losses of this crop. However, an unknown number of related species of pathogens of Peronosporales cause symptoms quite similar to those caused by P. cactorum. To determine their spectrum and importance, strawberry plants were sampled from 41 farms in the Czech Republic. The cultures were isolated from the symptomatic plants using the baiting method, with subsequent cultivation on a semiselective medium. Isolates were identified to the species level using nuclear ribosomal internal transcribed spacer (ITS) barcoding after preliminary morphological determination. In total, 175 isolates of 24 species of Phytophthora, Phytopythium, Pythium, and Globisporangium were detected. The most represented was Phytophthora cactorum, with 113 (65%) isolates, which was recorded in 61% of farms, and the Pythium dissotocum complex with 20 (11%) isolates, which was recorded in 27% of farms. Other species were represented in units of percent. Large differences between farms in the species spectra were ascertained. The differences between species in cardinal growth temperatures and different management of the farms are discussed as a main reason for such a diversification. Regarding the dissimilar sensitivity of various species of Peronosporales against fungicides, the proper determination of the cause of disease is of crucial significance in plant protection.
