ABSTRACT
Eight lichens were collected, identified and solvent extract were obtained using methanol and ethyl acetate in soxhlet apparatus. Antifungal properties of lichens were determined by Agar well diffusion method, Microdilution assay and TLC- Bioautographic technique. The largest zone of inhibition in well diffusion method was recorded (in mm) with the ethyl acetate extract of Parmotrema tinctorum with 18.6±1.15 followed by Teloschistes flavicans with 18.6±0.5. The maximum antifungal activity was found in the extracts of lichen Parmotrema tinctorum and Flavoparmelia caperata with low MIC value of 1.562mg/ml. Flavoparmelia caperata extract was active with a clear zone on TLC bioautogram of the tested organism indicating two zones of growth inhibition at an Rf value of 0.46, 0.6. Comparatively ethyl acetate extract showed a strong antifungal activity than methanolic extract. The results were promising with potential drug candidate having a fungitoxic effect to reinforce bioprospecting of lichens as a bio-fungicide.
ABSTRACT
The two different agro-ecosystems were selected to study the spore density, species abundance, and diversity of arbuscular mycorrhizal fungi (AMF) in irrigated (Mandya district) and non-irrigated (Hassan district) agricultural fields in southern Karnataka region, India. A total of 22 AMF species were recorded during the study. Out of which 13 sp. were of Glomus, 4 sp. of Acaulospora, 1 sp. of Cetraspora, 1 sp. of Dentiscutata and 3 sp. of Gigaspora. The difference in species richness of AMF species in irrigated fields ranged from 5-12 sp. as compared to non-irrigated fields (5-11 sp.) and the difference may be attributed to the nutritional status of the soil. We also assumed that lower AMF colonization and abundance would be affected by water stress. Highest spore number and percent colonization of AM fungi were recorded in irrigated sites, showing 356-748 spore density and 70-92 % colonization. Whereas, in non-irrigated sites, 174-341 spore density and 40-72 % colonization was recorded. Different agro-climatic conditions like irrigation, soil pH, soil organic carbon, phosphorous correlated with the abundance and colonization of AM fungi.
ABSTRACT
In the present investigation a pot culture experiment was conducted using sterile, phosphorus deficient soil to study the effect of flyash at 3 different concentrations (10g, 20g and 30g flyash/kg soil) on the infectivity and effectiveness of VAM fungus Glomus aggregatum in pigeonpea (Cajanus cajan (L.) Millsp.) cv Maruti. The flyash amendment in soil at all the 3 different concentrations was found to affect significantly the intensity of VAM fungal colonization inside the plant roots and also suppressed the formation of VAM fungal structure (vesicles and arbuscules) completely at higher concentration (30g flyash/kg soil). The response of the pigeonpea plants, as judged by their higher and dry weight, under the influence of flyash amendment in VAM fungus infested soils was found to be considerably less (though not significant enough) when compared to the control plants (without flyash) that have otherwise shown significant increase in growth over the plants without Glomus aggregatum inoculation. However, flyash amendment without VAM inoculation was also found to enhance the growth of plants as compared to control plants (without flyash and VAM inoculum).