Impact of Mutants of Trichoderma Species in Modulating Salinity Stress of Beans (Phaseolus vulgaris L. CV. Khomein)

The occurrence of salinity in Iran's agricultural soils is a growing problem and can cause a yield loss in the production of many products, including beans. Bio-priming with microorganisms tolerant to salinity stress (such as Trichoderma) is one of the biocompatible and effective solutions to solve this problem. The salinity treatment used in this study (NaCl ۱۰۰ mM) is doubling the tolerance threshold of the bean plant and the effect of biopriming with Trichoderma (wild-type and mutant) isolates has been investigated compared to the control plant. In order to increase tolerance to salinity in Iranian Trichoderma, mutation induction method using gamma radiation (۲۵۰ Gy) was used in this research. Growth components, germination, allometric index, seedling tissue water, and vigor were measured at seedling stage. Results from analysis of variance and comparison of the average showed that biological priming of beans with Trichoderma (wild type and mutant) fungal species had a significant advantage over control of salinity stress. However, the modulating effect of salt stress was greater in seeds inoculated with mutant species than in their wild type.