Abstract:

To explore whether the fungi from Parametarhizium， namely P. hingganense or P. changbaiense， a newly discovered fungus from forest litters in northeast China， could improve plant growth under salt and alkali stress， the mung bean seeds were treated with the fungi， followed by the examinations on the phenotypic changes， and alterations on the photosynthesis， chlorophyll fluorescence parameters， osmolyte contents， ROS levels， and antioxidant enzyme activities were detected respectively. The results showed that the biomass of mung bean plants treated with P. hingganense or P. changbaiense were higher under no-stress， salt and alkali stress conditions than untreated plants. Under salt and alkali stress， two fungus-treated plants maintained a high photosynthetic activity， elevated proline content， decreased malondialdehyde（MDA） content， and increased the activities of antioxidant enzymes POD， SOD and CAT in different degrees. In conclusion， through maintenance of photosynthesis， raising osmotic potential， and antioxidant capacity， treatment of the fungi from Parametarhizium alleviated the salt and alkali stress on mung bean. P. hingganense might significantly alleviate salt stress damage， while P. changbaiense might significantly improve the growth of mung bean under alkali stress.

Key words: Mung beans, salt and alkali stress, Parametarhizium, P.hingganense, P.changbaiense