شیراحمد سارانی

Rust fungi are belong to biotrophic fungi and are destructive plant pathogens. Due to the lack of consistent research related to rust fungi in the southeast of Iran, especially in the Sistan region, the present research was conducted in order to identify these fungi on vegetation based on the morphological characteristics of teliospore (shape, color, dimensions, presence or absence of pedicel, number of septum, surface ornamentation), urediniospore (shape, color, dimensions, number and position of germ pores, surface ornamentation) and aeciospore (shape, dimensions, surface ornamentation). Based on the results, Melampsora euphorbiae, Puccinia aeluropodis, P. bromina, P. carthami, P. cynodontis, P. isiacae, P. polypogonis, U. polygoni-avicularis, and U. rumicis were reported from Sistan region. Moreover, seven new host species including Bromus gedrosianus, Carthamus lanatus, Polypogon maritimus, Polypogon monspeliensis, Launaea procumbens, Polygonum argyrocoleon, and Rumex sanguineus were recognized for rusts fungi in Iran. The fungus isolated from Launaea procumbens belongs to the genus Puccinia, but its characteristics are different from the previously reported species on this host plant in other countries, including P. butleri and P. launaeae, and more investigations are required to determine the species.

The oomycete pathogens causing white blister rusts on members of Asteridae comprise different species within the genus Pustula (Albuginales, Oomycota). During the collection of white blister rust specimens in the South Khorasan province (eastern Iran) in April 2019, a specimen collected from Takhtajaniantha pusilla (Asteraceae), was identified morphologically as Pustula junggarensis (Albuginales, Oomycota). BLAST search using the ITS nrDNA sequence data, confirmed the identification. Also, the phylogenetic analysis using cox2 sequences clustered the species in the same clade with P. junggarensis sequences from China. This is the first record of P. junggarensis in Iran. To the best of our knowledge, this is the first report of a disease caused by a causative fungal/fungal-like agent on T. pusilla in Iran.

This study involved the collection of samples exhibiting powdery mildew symptoms from various locations in Kohgiluyeh and Boyer Ahmad Province. These samples were then meticulously examined to identify specific characteristics related to various structures, such as Casmothecium (including diameter, shape, and dimensions of appendages), sscus (shape, dimensions), ascospore (number per ascus, shape, dimensions), foot-cells of conidiophore (shape, dimensions), and conidium (solitary or catenate formation, shape, dimensions). This examination was conducted using multiple microscopic slides and detailed drawings of the structures were prepared using an Olympus CH30 microscope equipped with a drawing tube. The study revealed that Helichrysum oligocephalum represents a new host at the genus and species level for the genus Golovinomyces in Iran. Additionally, it was noted that there were no previous reports of powdery mildew on Vicia narbonensis in Iran. Furthermore, while some species had been previously documented in Iran, new host plants were identified for them. For instance, Bromus hordeaceus was identified as a new host for the Blumeria graminis species complex and Carduus pycnocephalus, Cirsium syriacus, and Jurinea carduiformis were found to be new hosts for Golovinomyces montagnei. Additionally, Erodium glauchophyllum and E. moschatum were identified as new hosts for Podosphaera erodii and Geranium pyrenaicum was found to be a new host for Podosphaera fugax. These findings introduced as new hosts of powdery mildew fungi in Iran.

Delaramifar M,  Pirnia M,  Keykhasaber M, Sarani SA,  Khajeh H (2023) Reaction of eight luffa genotypes to damping-off disease. Plant Pathology Science 12(2):76-85. 

Damping-off caused by Pythium aphanidermatum is one of the major diseases of luffa. Identifying and planting of resistant varieties is an environmentally friendly solution for integrated disease management. This study was conducted to determine the reaction of eight native and non-native luffa genotypes to the disease.

The pathogen (Pythium aphanidermatum IRAN597C) was obtained from the collection of fungi of the Iranian Institute of Plant Protection Researches. It was inoculated into seedlings of eight luffa genotypes. After the appearance of yellowing symptoms and seedling death, the disease index (DI) and the area under the disease progression curve (AUDPC) were calculated for each genotype. Koch's postulates were carried out to prove pathogenicity and the pathogen was isolated from diseased seedlings. Then, for molecular confirmation of the pathogen, ITS-rDNA sequencing was used.

The sequencing of the ITS-rDNA region of the pathogen showed a phylogenetic affinity of 99% with other isolates of P. aphanidermatum. According to the DI, the northern large and the long luffa genotypes were grouped as sensitive genotypes, and other genotypes including northern black seed, northern white seed, toori, Afghani, grooved and Brazilian were grouped as resistant genotypes. Based on the AUDPC, the northern black seed, and northern white seed genotypes showed the lowest level, toori, grooved, Afghani and Brazilian genotypes showed the medium level, and northern large and long luffa genotypes showed the highest AUDPC level.

Considering the low values of the DI and AUDPC in the northern black seed and northern white seed genotypes, planting these two genotypes is suggested for management of the disease in luffa.

Seemingly worthless agricultural residues (wheat straw, olive pomace) and industrial (wood chips, sugarcane bagasse) constitute a large amount of waste that leads to environmental pollution and health hazards. Fungi, as consumers of organic matter wastes, establish a material recycling cycle and also eliminate the problems related to air pollution caused by the incineration of wastes.

The present study was conducted with a completely randomized design with three replicates in Sistan Damfarm in 2019. Experimental treatments include substrates of wood chips, wheat straw, sugarcane bagasse, sugarcane bagasse+wheat bran (90 to 10), sugarcane bagasse+olive pomace (90 to 10), wood chips+wheat bran (90 to 10), wood chips+olive pomace (90 to 10), wheat straw+olive pomace (90 to 10), wheat straw+wheat bran (90 to 10). Spawn of H. ulmarius and A. aegerita fungi were prepared and the substrates were inoculated with spawn.

In the fungus H. ulmarius, the highest yield (467.54 g), dry matter (50.24 g), the highest amount of total polysaccharide (12.29 mg/g dry matter) and the shortest time (14 days) required to complete the spawn run. The lowest time for precocity (26 days) was allocated to the combined substrates of wheat straw with wheat bran (90 to 10). In the fungus A. aegerita, the highest yield (72.81 g), dry matter (9.22 g), the highest amount of total polysaccharide (11.33 mg/g dry matter) and the shortest time (15 days) required to complete the spawn run. The lowest time for precocity (29 days) was allocated to the combined substrates of wood chip with wheat bran (90 to 10).

A wheat straw substrate for H. ulmarius and wood chip substrate for A. aegerita were introduced as the best substrates.

White blister rust causal agents, previously assigned to the genus Albugo, are obligate plant pathogens affecting numerous plant families. The genus Wilsoniana has been erected from the genus Albugo to accommodate species infecting hosts in the Caryophyllales. Starting from spring 2018, we observed symptoms resembling white blister rust disease on leaves of Amaranthus retroflexus L. in the northern Iran. The specimens were subjected to molecular study by analyzing cox2, LSU and ITS rDNA sequences and morphological data sets. The results confirmed that the specimens belong to Wilsoniana amaranthi (Schwein.) Y.J. Choi, Thines & H.D. Shin (Albuginales, Oomycota). To our knowledge, this is the first confirmed and documented record of W. amaranthi (ex Amaranthus retroflexus) from both Iran and West Asia. The results of this study will provide a reference for further resolution of W. amaranthi species concept.

The pathogens causing white blister rusts (Albuginales, Oomycota) comprises three genera including Albugo, Pustula and Wilsoniana infecting species of Brassicaceae, Caryophyllales and Asteridae, respectively. The current study contributes with new knowledge on Albuginales in Iran. An extensive survey for sampling white blister rust specimens was performed during the 2017-2020 growing season in some regions in Eastern and Northern Iran. Based on morphological and molecular (Cox2 and ITS) data Albugo lepidii on Lepidium sativum, A. koreana on Camelina transcaspica, Albugo arenosa on Strigosella africana, A. candida on various hosts, A. occidentalis on spinach and Wilsoniana portulacae on Portulaca sp. were identified. Our results, represent the first morphologically and molecularly verified report of A. candida on Goldbachia laevigata, Raphanus sativus, Eruca sativa from Iran and on Sinapis arvensis, Savignya parviflora, Isatis leuconeura and Sisymbrium altissimum worldwide. Sisymbrium septulatum is reported as Matrix nova for A. candida. White blister rust caused by A. candida is reported for the first time on a member of the genus Savignya in Iran. Albugo lepidii and A. koreana are new records for Iranian mycobiota. Detailed descriptions and illustrations along with phylogenetic placement here are provided for Wilsoniana portulacae and Albugo occidentalis.

Two hundred fifty seven bacterial isolates were collected from colza root and rhizosphere in Golestan, Mazandaran, Guilan and Tehran provinces. Antagonistic effect of bacterial isolates on Rhizoctonia solani, the causal agent of colza damping off, was studied using dual culture method. The results showed that, 60 isolates had the ability to inhibit the growth of R. solani on PDA medium. On the basis of the biochemical, physiological and morphological tests, isolates P1, P2 and P3 were identified as Pseudomonas fluorescens. Biocontrol mechanism studies showed that isolates produced antibiotics and volatile metabolites prevented the mycelial growth of the fungus. The isolates produced some of antimicrobial metabolites including hydrogen cyanide, protease and siderophore. Isolate P3 was more effective to inhibit the growth of the fungus in-vitro. The effect of isolates on disease reduction in comparison with control was significantly different. None of the isolates were able to prevent disease occurrence completely. Isolates applied as soil treatment had a significantly higher disease control as compared to seed treatment method. Isolate P3 had considerable effect on reduction disease in the greenhouse conditions. All isolates were capable of colonizing canola roots and so increased canola growth in free-causal agent conditions.