The importance of plant protection in modern agriculture increases as crop yields and concerns about production quality rise. Plant protection should be sufficiently effective, affordable and considerate of the environment. The integration of biological and chemical control has a potential for success because of a possible synergistic effects. It is necessary to look for organisms suitable for use in biological control, and in order to study the mechanisms of their action and the optimal conditions for incorporating such agents in plant protection and integrated management systems. One of such microorganisms is PythiumoligandrumDrechslerthatbelongs to the phylumOomycetes. This soil-resident saprophytic microorganism can be parasitic and hyperparasitic on many fungi within the same or other classes. The antagonistic activity of P. oligandrumis a multifaceted process which depends on the target species involved. P. oligandrumis nonpathogenic on 12 species of crops that belong to six families. It occurs on the root surface together with plant pathogenic fungi, predominantly in the regions of hypocotyl – taproot without penetrating the plant tissues. The plant growth is reportedly stimulated by this species. P. oligandrum can be utilized for biological control on a wide spectrum of crop plants. Different methods of application have been developed. The most effective activity of this microorganism is the mycelial growth inhibition of the plant pathogenic fungi.
Tahereh Soleimani, Mojtaba Keykhasaber, Mohammad Ali Aghajani, Mahdi Pirnia, Leila Fahmideh, Volume 14, Issue 1 ((Autumn & Winter) 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.
