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2019 - 201912020 - 20221
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Subject: Nematology × Author: Sharma, Lochan × Type: Thesis ×
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    ThesisItemOpen Access
    Studies on development and bioefficacy of chitosan based nano formulation (s) against root knot nematode, Meloidogyne incognita
    (Chaudhary Charan Singh Haryana Agricultural University hisar, 2022-11) Sharma, Lochan; Banakar, Prakash
    Present study was conducted to investigate the synthesis, characterization and bioefficacy of chitosan based nanoformulation (s) against root knot nematode, Meloidogyne incognita. Nanoparticles were synthesized by ionic gelation method and characterized by DLS, FTIR, FESEM and TEM. The DLS results confirmed the size, stability and charge of synthesized Cu-chitosan and chitosan-saponin NPs.Whereas FTIR, FESEM, FESEM-EDS and TEM, observations confirmed the functional group, crystalline porous structure, elemental compostion and spherical shape of synthesized nanoparticles. Encapsulation and release profile of Cu was confirmed by ICP-MS under varying pH and time.Maximum Cu release confirmed at pH 1 and 144 h of time period. In in vitro, assay results revealed that increasing the concentration and time exposure of Cu-chitosan and chitosan-saponin NPs leads to more nematode mortality and egg hatching inhibition. The maximum mortality and egg hatching inhibition was documented in 1000 ppm of Cu-chitosan NPs after 72 and 96 h respectively. In pluronic gel experiment NPs exposure to M. incognita juveniles for 16 h affect host finding behavior. A minimum number of juveniles reached around tomato roots were observed in chitosan-saponin NPs at 1200 ppm in 4 and 8 h as compared to water and octopamine control. Increasing the NPs concentration reduced nematode penetration and minimum number of nematode penetrated in 1200 ppm of chitosan-saponin NPs as compared water control in tomato roots. In management experiment foliar spray was more effective in increasing the plant growth parameters as compared to seedling root dip and soil drenching method. But, in reduction of nematode parameters observed in seedling root dip treatment (8 h) was more effective as compared to 4 h seedling root dip and other treatments. Cu-chitosan is more effective in reduction of number of galls, number of egg masses, eggs per egg mass and soil population per 200 cc soil, while chitosan-saponin NPs was more effective in increasing plant growth parameters. It was observed NPs also caused toxicity in M. incognita J2s and up regulates the detoxifying genes. Hence, the chitosan based nano formulation (s) proved to be of great nematicidal potential and opened new opportunities for expanding their effectiveness as new nematode control agents.
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    ThesisItemOpen Access
    Studies on interaction between Heterodera avenae and Urocystis agropyri causing flag smut in wheat
    (CCSHAU, 2019) Sharma, Lochan; Kanwar, R.S.
    Present study was conducted to investigate the effect of different soil types on interaction of Heterodera avenae and Urocystis agropyri, the effect of sowing times on interaction between H. avenae and U. agropyri and the effect of different nematode inoculum levels on interaction of H. avenae and U. agropyri. The experiments were conducted in screen house of Department of Nematology, CCSHAU, Hisar during Rabi-2018. For evaluating the effect of different soil types on interaction between H. avenae and U. agropyri wheat cultivar HD2967 was sown in 1 kg earthen pots and observations of plant growth parameters, disease incidence and nematode population were recorded at crop maturity. Chlorophyll was measured by SPAD meter. Plant growth parameters and chlorophyll was minimum in H. avenae and U. agropyri simultaneous inoculation in loamy sand soil. There was no effect on germination and tillering by either of the pathogen. Final cyst population was more in loamy sand soil and in presence of fungus nematode population was decreased. For comparing the effect of different sowing times, wheat was sown in first week of November, last week of November and second week of December. Maximum reduction in plant growth parameters and chlorophyll was observed in simultaneous inoculation of nematode and fungus in last week of November. Maximum reduction of chlorophyll was observed 60 days after sowing in N+F as compared to uninoculated control. There was no effect of either pathogens alone or in combination on germination and tillering. Maximum cyst population was recorded in last week of November sown plants. In the experiment on effect of different inoculum levels viz. 5, 10 and 15 eggs and J2/g soil of H. avenae and constant level of U. agropyri 20g/kg seed on plant growth parameters and chlorophyll content, plant height, weight and chlorophyll were minimum in simultaneous inoculation of at 15 eggs and J2 of nematode with fungus. Maximum cysts were obtained at highest inoculum of H. avenae i.e. 15 eggs and J2/ g soil. In presence of fungus, cyst population was decreased.