Microbiology and Biotechnology Research: An Overview Vol. 9

Plant health is greatly influenced by the presence of various microorganisms in the rhizosphere and phylloplane. The present investigation was conducted to study the spectrum of mycoflora associated with the phylloplane and rhizosphere of Aloe vera and to assess their effects on plant growth parameters and their antagonistic activity against C. gloeosporioides, which causes black spot disease in Aloe vera. For the isolation of phylloplane mycoflora, both healthy and diseased leaves were randomly collected from different plants. During the study, a total of 15 fungal isolates belonging to ten genera were isolated from Aloe vera using the leaf-washing technique for the phylloplane and serial dilution for rhizosphere soil. Among these, fungal species belonging to the genera Aspergillus, Trichoderma, and Penicillium were more abundant. Rhizosphere isolates were further evaluated under pot conditions in a greenhouse to determine their plant-growth-promoting potential. The results revealed significant variation among the isolates in their effects on plant growth. Isolates of Fusarium, Cladosporium, Curvularia, and Alternaria exhibited negative effects, leading to reduced plant height, fresh and dry leaf weights, and root biomass after 15 days of inoculation. The antagonistic potential of beneficial mycoflora from both the phylloplane and rhizosphere was assessed using the dual-culture technique. All beneficial isolates demonstrated strong inhibition (>65%) of pathogen growth on PDA medium. Overall, the study indicates that certain mycoflora associated with the phylloplane and rhizosphere of Aloe vera can promote plant growth and exhibit substantial antagonistic activity against Colletotrichum gloeosporioides.