Gorgan University Of Agricultural Sciences Journal of Soil Management and Sustainable Production 2322-1267 14 3 2024 09 22 Evaluation of salinity tolerance of some plant growth-promoting fungi and introduction of the best formulation for salinity-tolerant fungi Evaluation of salinity tolerance of some plant growth-promoting fungi and introduction of the best formulation for salinity-tolerant fungi 143 160 7119 10.22069/ejsms.2024.21924.2127 FA Rostam Yazdani Biouki Assistant Professor, National Salinity Research Center, Agricultural Research, Education and Extension Organization (AREEO), Yazd, Iran Hossein Kari Dolatabad Assistant Professor Soil biology department,, Soil and Water Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran Mitra Rahmati Assistant Professor, Seed and Plant Certification and Registration Research Institute, Agricultural Research, Education and Extension Organization, Karaj, Iran Journal Article 2023 11 15 Background and objectives: Plant growth promoting fungi are often useful for plants and make host plants adapt to living and non-living stressors, including salt stress, in different ways. In this regard, the identification and application of growth-promoting fungi that tolerate salt stress is one of the ways to deal with and adapt to salt stress conditions. On the other hand, different carriers have different ability to maintain the population of these fungi at the standard level and maintain their efficiency. Also, storage conditions, especially temperature, can have a great effect on their population and stability. Therefore, the present research was conducted with the aim of preparing suitable formulations of salt-tolerant fungi in order to preserve and stabilize their population in the long term.<br />Materials and methods: In the present study, Chaetomium globosum, Chaetomium interruptum, Clonostachys rosea, Coniothyrium sp., Epicoccum nigrum, Serendipita indica, Trichoderma asperellum, Trichoderma atroviride, Trichoderma harzianum, Trichoderma longibrachiatum and Trichoderma reesei with plant growth-promoting properties were obtained from the collection of the Department of Soil Biology and Biotechnology of the Soil and Water Research Institute in order to identify the fungal species tolerant to salinity. Their growth potential at different salinity levels including 0.045, 0.31, 0.63, 1.04, 1.36, 2.14, 3.04, 3.95 and 4.71 percent of sodium chloride<br />was evaluated in a completely randomized design with three replications. Also, two salt-tolerant fungal species and different carriers (pepper waste, vermiculite, stone powder, pumice, perlite, sawdust, and compost) were used to evaluate the stability of the fungal population in different formulations. The experiment was laid out in a factorial completely randomized design with three replications.<br />Results: The results showed that T. harzianum, T. atroviride, T. longibrachiatum, and T. reesei were less affected by the salinity of 0.045 to 4.71% sodium chloride and were able to fill the entire surface of the Petri dish (8cm) at different salinity levels. E. nigrum was also able to grow at different salinity levels, although its growth decreased with increasing salinity. T. harzianum was the only species that was able to cover the entire Petri-dish surface in seven days at the culture medium containing 2.14% sodium chloride. The formulation results showed that the carrier effect was significant in both T. harzianum and E. nigrum species. Compost, sawdust, and vermiculite were the best carriers in terms of maintaining the Trichoderma population. The best carriers in maintaining T. harzianum population after six months at cold room temperature was vermiculite (4 × 109 CFU/g), compost (3.66 × 109 CFU/g) and sawdust (3 × 109 CFU/g) and in E. nigrum species was compost (1 × 108 CFU/g) and vermiculite (8 × 107 CFU/g).<br />Conclusions: In general, the results showed that T. harzianum and E. nigrum species were able to grow in culture media containing 4.71% sodium chloride and the best carriers for the formulation of these two fungi were compost and vermiculite. Background and objectives: Plant growth promoting fungi are often useful for plants and make host plants adapt to living and non-living stressors, including salt stress, in different ways. In this regard, the identification and application of growth-promoting fungi that tolerate salt stress is one of the ways to deal with and adapt to salt stress conditions. On the other hand, different carriers have different ability to maintain the population of these fungi at the standard level and maintain their efficiency. Also, storage conditions, especially temperature, can have a great effect on their population and stability. Therefore, the present research was conducted with the aim of preparing suitable formulations of salt-tolerant fungi in order to preserve and stabilize their population in the long term.<br />Materials and methods: In the present study, Chaetomium globosum, Chaetomium interruptum, Clonostachys rosea, Coniothyrium sp., Epicoccum nigrum, Serendipita indica, Trichoderma asperellum, Trichoderma atroviride, Trichoderma harzianum, Trichoderma longibrachiatum and Trichoderma reesei with plant growth-promoting properties were obtained from the collection of the Department of Soil Biology and Biotechnology of the Soil and Water Research Institute in order to identify the fungal species tolerant to salinity. Their growth potential at different salinity levels including 0.045, 0.31, 0.63, 1.04, 1.36, 2.14, 3.04, 3.95 and 4.71 percent of sodium chloride<br />was evaluated in a completely randomized design with three replications. Also, two salt-tolerant fungal species and different carriers (pepper waste, vermiculite, stone powder, pumice, perlite, sawdust, and compost) were used to evaluate the stability of the fungal population in different formulations. The experiment was laid out in a factorial completely randomized design with three replications.<br />Results: The results showed that T. harzianum, T. atroviride, T. longibrachiatum, and T. reesei were less affected by the salinity of 0.045 to 4.71% sodium chloride and were able to fill the entire surface of the Petri dish (8cm) at different salinity levels. E. nigrum was also able to grow at different salinity levels, although its growth decreased with increasing salinity. T. harzianum was the only species that was able to cover the entire Petri-dish surface in seven days at the culture medium containing 2.14% sodium chloride. The formulation results showed that the carrier effect was significant in both T. harzianum and E. nigrum species. Compost, sawdust, and vermiculite were the best carriers in terms of maintaining the Trichoderma population. The best carriers in maintaining T. harzianum population after six months at cold room temperature was vermiculite (4 × 109 CFU/g), compost (3.66 × 109 CFU/g) and sawdust (3 × 109 CFU/g) and in E. nigrum species was compost (1 × 108 CFU/g) and vermiculite (8 × 107 CFU/g).<br />Conclusions: In general, the results showed that T. harzianum and E. nigrum species were able to grow in culture media containing 4.71% sodium chloride and the best carriers for the formulation of these two fungi were compost and vermiculite. https://ejsms.gau.ac.ir/article_7119_dd44f98148095e6b6609cef6a08e800c.pdf