Ghaderi F, Mohammadi H (2023)Occurrence of jujube brown spot disease in Iran. Plant Pathology Science 12(2):95-104.
Jujube tree has a natural distribution in tropical and sub-tropical regions of Asia. Symptoms of brown-to-black spots on leaves, and fruits, and twigs blight were observed in the hills of the suburbs of Nurabad County, Fars Province, Iran, in 2022. This research was conducted to identify the cause of this disease based on morphological and genetic characteristics. The diseased leaves and branches of the neighboring trees in this area were sampled. The pathogen was isolated and purified after surface disinfection of disease tissues on potato/dextrose/agar medium. Its morphological characteristics were studied and the fungus Nothophoma quercina was identified. Phylogenetic analysis base on the comparison of beta-tubulin (tub2), and ITS-rDNA genes sequences, with related fungi in NCBI Gen Bank, confirmed the of N. quercina species. Its pathogenicity was proved on the side cut jujube branches based on Koch's postulates in vitro. This is the first report of brown spot and twigs blight of the jujube trees caused by N. quercina in Iran.
Mirzaeipour Z, Bazgir E, Zafari D, Darvishnia M (2023) Effect of temperature and culture medium on the growth and sporulation of eight Trichoderma species. Plant Pathology Science 12(2):105-116. DOI: https://doi.org/10.2982/PPS.12.2.105
Trichoderma species are important agents of biological control of soil-borne plant pathogens. The growth and reproduction of these fungi are influenced by the culture medium and temperature. This study was conducted to determine the effect of temperature and culture medium on the growth and sporulation of Trichoderma species. Ten isolates of Trichoderma species were isolated from agricultural soils of different regions of Lorestan Province, Iran. The study of morphological characteristics and sequencing of ITS-rDNA, and tef1α gene regions showed that they are belong to eight species of Trichoderma. Investigating the effect of four types of culture medium and five temperatures to determine optimum culture medium and temperature for the growth and reproduction of these fungi, showed that the Potato/Dextrose/Agar (PDA) medium is the best, and the temperature of 20 to 30 degrees Celsius is optimal for the growth and reproduction of these fungi. Evaluation of their ability to inhibit the growth of the soil-borne plant pathogenic fungus Rhizoctonia solani in vitro, showed that T. harzianum LT8 has the most inhibition ability. Therefore, this isolate can be used as a potential biocontrol agent for this plant pathogenic fungus in future research.
Introduction: 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. Materials and Methods: 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. Results: 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. Conclusion: 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.
Tahereh Soleimani, Mojtaba Keykhasaber, Mohammad Ali Aghajani, Mahdi Pirnia, Leila Fahmideh, Volume 14, Issue 1 (2-2025)
Abstract
Rice is a major food crop in Asia. Fungal diseases such as root, collar, and stem rot, as well as leaf sheath blight, are common in most rice-growing regions of Iran and cause significant economic losses. This study was conducted to identify the fungal pathogens responsible for these diseases in Golestan Province, which ranks third in rice production in the country. Identifying these pathogens provides a foundation for implementing effective management strategies and improving crop yield. Samples showing symptoms of root and stem rot and leaf sheath blight were collected from rice fields across various locations in Golestan Province. Fungi were isolated from diseased tissues using water agar and potato dextrose agar media and then purified. For precise molecular identification, the polymerase chain reaction (PCR) was used to amplify the tef1-α and ITS-rRNA gene regions with the primers EF1728F/EF1-986R and ITS5/ITS4, respectively. Pathogenicity tests were conducted on rice seedlings under greenhouse conditions. Based on morphological, molecular, and pathogenicity analyses, the following fungal pathogens were identified in the diseased samples: Ceratorhiza hydrophila, Fusarium andiyazi, F. incarnatum, and Rhizoctonia solani. This is the first report of C. hydrophila, F. andiyazi, and F. incarnatum occurring in rice fields in this province.
Rapeseed is one of the major oilseed crops worldwide. Owing to its high yield potential per unit area, its cultivation has expanded considerably over the past three decades in many countries, including Iran. Several soil-borne fungi can cause root and crown rot of rapeseed. This study was conducted to identify fungi associated with the roots and crowns of diseased rapeseed plants collected from fields in Lorestan Province, western Iran. Sixty-one samples were collected from the roots and crowns of diseased rapeseed plants in Mamulan, Khorramabad, and Selseleh counties of Lorestan Province, Iran, during the 2023–2024 growing season. Fungi were isolated and purified using selective culture media, and their morphological characteristics were examined. Molecular identification was performed by sequencing the internal transcribed spacer (ITS) and translation elongation factor 1-alpha (TEF1-α) genomic regions. Phylogenetic relationships between the obtained isolates and other species within the corresponding genera were subsequently determined. Based on morphological and phylogenetic analyses, four fungal species associated with diseased rapeseed roots and crowns in the study area were identified as Fusarium clavum, Bipolaris coffeana, Alternaria alternata, and Alternaria tenuissima. Fusarium clavum has previously been reported as a causal agent of root and crown rot of rapeseed in Iran. Bipolaris coffeana is reported for the first time from rapeseed in Lorestan Province. The results demonstrate that the integration of morphological characteristics with sequencing of the ITS and TEF1-α genomic regions provides a reliable and accurate approach for identifying species of Alternaria, Fusarium, and Bipolaris. The morphological characteristics of the identified fungi are described, and their phylogenetic relationships with other species within each genus are presented. The findings highlight the importance of continuous monitoring of soil-borne fungal pathogens in rapeseed-growing fields to facilitate their timely detection and effective disease management.
