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

Salinity in Iran's agricultural soils is a growing problem and can cause yield loss in the production of many products, including beans. One of the most biocompatible and effective solutions to this problem is bio-priming with microorganisms tolerant to salinity stress (such as Trichoderma). This study's salinity treatment (NaCl 100 mM) doubles the tolerance threshold of the bean plant and the effect of biopriming with Trichoderma isolates (wild-type and mutant) has been investigated. A mutation induction method (250 Gy) was used to increase tolerance to salinity in Iranian Trichoderma. Growth components, germination, allometric index, seedling tissue water, and vigor were measured at the 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.