Navgire, K.D.Deore, Pankaj Bhatu2023-05-152023-05-152022-12-1923312https://krishikosh.egranth.ac.in/handle/1/5810197307The beneficial soil microorganisms are important in maintaining soil health. The novel nano-pesticides and nano-fertilizers are introduced in agriculture to enhance crop production and productivity but after their use, they are leached out in the soil. Many researchers have reported the toxic effect of nanoparticles on various microorganisms and plants but very little data is available on the effect of NPs on beneficial microorganisms. Therefore the present investigation was carried out to explore the effect of Cu and Ag NPs on beneficial microorganisms such as Trichoderma. The green synthesis of Cu and Ag NPs were carried out by using Azadirachta indica leaf extract as a precursor and 1 mM aqueous solution of CuSO4.5H2O and AgNO3 respectively as a reducing agent in 1:5 proportion and incubated at 26 oC for 12 hrs and 24 hrs respectively. The color change reaction confirmed the formation of NPs. The NPs were purified by repeated washing and dried at 60 oC for 2 hrs. The powder form CuNPs and AgNPs were of coffee brown and dark gray color respectively. The green synthesized CuNPs and AgNPs were characterized by SEM, EDX, DLS and Zeta potential. The CuNPs and AgNPs appeared as nanoclusters crowded together with biomolecules but under higher magnification, they appeared spherical. The average particle size distribution of CuNPs and AgNPs was in the range of 141.8 to 3091 nm and 11.70 to 58.77 nm respectively with an average size of 1202 nm and 107.9 nm respectively. The green synthesized CuNPs were moderately polydispersed (0.286 PdI) and AgNPs were broadly polydispersed (0.602 PdI). The elemental composition of green synthesized CuNPs and AgNPs included 6.11 per cent of Cu and 48.63 per cent of Ag on a weight basis and 1.73 per cent of Cu and 15.14 per cent of Ag on an atomic percent basis. The green synthesized CuNPs and AgNPs were negatively charged with Zeta potential -6.54 mV and -4.38 mV respectively. The green synthesized CuNPs and AgNPs were evaluated against T. viride and T. harzianum. The CuNPs doses of 1-1000 ppm/L not affected the linear growth of T. viride and T. harzianum. The minimum inhibitory concentration of green synthesized AgNPs against T. viride was 100 ppm/L and 90 ppm/L against T. harzianum. The growth rate of T. viride was hampered by 1-1000 ppm/L doses of CuNPs in the initial growth period up to 48 hrs but later on, no effect of CuNPs was observed while AgNPs doses affected the growth rate erratically at 24 hrs, 48 hrs and 72 hrs. The 1-1000 ppm/L doses of Cu and Ag NPs variably affected the colony zone length of T. viride and T. harzianum but different doses of NPs not showed a consistent effect on colony zone length. The CuNPs and AgNPs doses variably affected the colony zone color of T. viride at 72 hrs (3rd day) and 96 hrs (4th day) as compared to the untreated control. The CuNPs doses not affected the colony zone color of T. harzianum at 72 hrs but at 96 hrs, only the productive zone showed variation in color as compared to the untreated control. In T. viride and T. harzianum at 96 hrs, the fuzziness gets increased in extending zone and productive zone respectively with an increase in CuNPs dose. The AgNPs doses affected the colony zone color of T. viride and T. harzianum at 72 hrs except extending zone of T. harzianum. At 96 hrs, only the fruiting zone of T. viride was not affected the colony zone color by 25 ppm/L, 50 ppm/L, 100 ppm/L, 250 ppm/L and 750 ppm/L doses of AgNPs but in T. harzianum only fruiting zone at 750 ppm/L and 1000 ppm/L and ageing zone at 1 ppm/L doses of AgNPs were unaffected the colony zone color. The CuNPs and AgNPs doses affected some cultural characteristics of T. viride and T. harzianum but not affected the colony form/shape, elevation, margin/border, opacity, conidiation and exudates on the colony at 72 hrs and 96 hrs. The 1-1000 ppm/L doses of CuNPs affected the colony color of T. viride but not affected the colony color of T. harzianum at 72 hrs and 96 hrs. All the doses of AgNPs affected the colony color of T. viride at 72 hrs but at 96 hrs, only 25-250 ppm/L doses not affected the colony color of T. viride while in T. harzianum only 1 ppm/L dose of AgNPs not affected the colony color at 72 hrs but at 96 hrs all the doses of AgNPs affected the colony color. The colony surface texture of T. viride and T. harzianum was woolly and not affected by any CuNPs at 72 hrs and 96 hrs but in T. harzianum, woolliness was increased at 96 hrs with an increase in the dose of CuNPs from 100 ppm/L to 1000 ppm/L. In T. viride, the AgNPs not affected the colony surface texture at 72 hrs but at 96 hrs only 1 ppm/L, 100 ppm/L, 750 ppm/L and 1000 ppm/L doses of AgNPs affected the colony surface texture while in T. harzianum, the 100-1000 ppm/L doses of AgNPs only affected the colony surface texture at 72 hrs but at 96 hrs, all the doses (1-1000 ppm/L) of AgNPs affected the colony surface texture of T. harzianum. The pigmentation of T. viride and T. harzianum was affected by 250-1000 ppm/L doses of CuNPs and 500-1000 ppm/L doses of AgNPs. Only the sporulation of T. viride was affected at 72 hrs by 1-1000 ppm/L doses of AgNPs. The colony ring formation in T. viride and T. harzianum was unaffected by 1-1000 ppm/L doses of CuNPs. The colony ring formation at 72 hrs was affected by some doses of AgNPs at 72 hrs in T. viride and T. harzianum. The colony ring formation at 96 hrs, was not affected by AgNPs in T. harzianum but in T. viride, 25 ppm/L, 100 ppm/L and 250 ppm/L doses of AgNPs only affected the colony ring formation. The colony reverse color of T. viride was affected by all the doses (1-1000 ppm/L) of CuNPs and AgNPs but 250-1000 ppm/L the doses of CuNPs and AgNPs affected the colony reverse color of T. harzianum. The 10-1000 ppm/L dose of CuNPs recorded the colony surface and back grooves in T. viride and 1 ppm/L dose of CuNPs in T. harzianum but the colony surface and back grooves of T. viride and T. harzianum were not affected by AgNPs. The CuNPs and AgNPs showed an inconsonance and consonance effect respectively on conidia production and conidia viability of T. viride and T. harzianum. In T. viride, 1 ppm/L, 25 ppm/L and 500 ppm/L doses of CuNPs and in T. harzianum, 1 ppm/L, 10 ppm/L, 50 ppm/L and 100 ppm/L doses of CuNPs hampered the conidia production and conidia viability as compared to untreated control while rest of all CuNPs doses promoted the conidia production and conidia viability in T. viride and T. harzianum. In T. viride and T. harzianum, the AgNPs affected the conidia production and conidia viability and with the increase in the dose of AgNPs, conidia production and conidia viability got decreased. The CuNPs and AgNPs showed a random effect on the volatile compound production of T. viride and T. harzianum which leads to the inhibition of FOL. The serial increase in the doses of NPs didn’t show any cumulative or noncumulative effect on the volatile compound production of T. viride and T. harzianum. The volatile compound production in T. harzianum was markedly get enhanced as compared to T. viride by the treatments of CuNPs and AgNPs. The volatile compound production of T. harzianum was enhanced by 1-1000 ppm/L doses of CuNPs while 1000 ppm/L, 750 ppm/L, 250 ppm/L, 25 ppm/L and 10 ppm/L dose of CuNPs only enhanced volatile compound production of T. viride. The volatile compound production of T. viride and T. harzianum was enhanced by the treatment of AgNPs as compared to the control except doses 25 ppm/L and 250 ppm/L in T. viride and 750 ppm/L in T. harzianum. The different doses of CuNPs and AgNPs showed a variable effect on the non-volatile compound production of T. viride and T. harzianum. An increase in the concentration of culture filtrates of T. viride and T. harzianum in each NP treatment showed a decrease in the linear growth of FOL and increased inhibition of FOL. In T. viride, the 1 ppm/L dose of CuNPs recorded the highest inhibition of FOL at 5 per cent, 10 per cent and 50 per cent concentration of culture filtrates and 10 ppm/L dose of CuNPs at 1 per cent and 25 per cent concentration of culture filtrates while 50 ppm/L dose of AgNPs recorded the highest inhibition of FOL at 1 per cent, 5 per cent, 10 per cent, 25 per cent and 50 per cent concentration of culture filtrates. In T. harzianum, the 750 ppm/L dose of CuNPs recorded the highest inhibition of FOL at 1 per cent, 5 per cent, 10 per cent, 25 per cent and 50 per cent concentrations of culture filtrates but at 25 per cent and 50 per cent concentration of culture filtrates all the CuNP treatments recorded lower inhibition of FOL than the untreated control while, 1 ppm/L dose of AgNPs recorded the highest inhibition of FOL at 1 per cent, 5 per cent, 10 per cent, 25 per cent and 50 per cent concentrations of culture filtrates. The CuNPs and AgNPs showed a variable effect on the antagonistic activity and inhibition zone of T. viride and T. harzianum. The CuNPs showed an increase in the antagonistic activity of T. viride and the highest inhibition of FOL was observed at 1000 ppm/L dose of CuNPs while only 1 ppm/L, 50 ppm/L and 250 ppm/L doses of AgNPs recorded an increase in the antagonistic activity of T. viride. The AgNPs recorded decreased antagonistic activity of T. harzianum while only 750 ppm/L, 1000 ppm/L and 10 ppm/L doses of CuNPs recorded an increase in the antagonistic activity of T. harzianum. The present investigations find out the effect of Cu and Ag NPs on T. viride and T. harzianum but further detailed investigations are needed to clearly understand the interactions of Cu and Ag NPs with T. viride and T. harzianum.EnglishThesis