CHARACTERIZATION AND IN VITRO SCREENING OF DIFFERENT ENDOPHYTIC FUNGI ON RICE FOR GROWTH PROMOTION UNDER HEAVY METAL STRESS

초록

Continued industrialization around the world has resulted in major threats to agricultural soil. Soil contaminated with heavy metals is a primary challenge for crop production. Their complete removal from the soil is needed. However, the use of plant growth-promoting microbes might mitigate the adverse effects of HMs in crop plants and can be used as a bioremediation tool. In the present study, the tolerance of different endophytic fungi against two different concentrations of cadmium and chromium was investigated. For the purpose, isolated endophytes were screened on Oryza sativa L. seedlings. The results revealed that out of 29 fungal isolates, 4 strains inhibited the plant growth, while remaining were growth-promoting. Of the growth-promoting strains, best results were shown by endophytes, Ch-01 (Aspergillus flavus) and Ch-06 (Aspergillus violaceofirscus), isolated from chilli and Cu-02 (Aspergillus fumigatus), Cu-10 (Aspergillus awamori) and Cu-17 (Aspergillus niger), isolated from Cucurbita. Their association with 0. saliva not only showed an enhancement in growth attributes under Cd and Cr stress, but also resulted in a declined accumulation of Cd and Cr content in 0. saliva seedlings. From the results, it is concluded that A. flavus, A. violaceofuscus, A. fumigatus, A. awamori and A. niger are plant growth-promoting and HMs resistant endophytes, which can significantly improve plant growth in Cd and Cr polluted soils. Hence, these endophytes can be used as biofertilizer in fields affected by heavy metals.

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