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ThesisItem Restricted Characterization and evaluation of rice straw lignin phenolics on pollen germination in pumpkin(Punjab Agricultural University, Ludhiana, 2021) Jasleen Kaur; Ramandeep KaurRice straw is one of the most abundant, renewable, cost-effective and non-edible agricultural feedstocks. Its burning has led to air pollution, loss of soil fertility and nutrient depletion, therefore valorization of rice straw is important. Straw was found to be chemically composed of 24% hemicellulose, 41% cellulose, 9% lignin, 20% extractives and 6% ash (silica). Lignin was extracted using dilute acid pretreatment (1% H2SO4) followed by alkaline hydrolysis using NaOH. FT-IR, 1H and 13C NMR were used for structural characterization of the lignin obtained from rice straw. The ethyl acetate extract of acid solubilized lignin was found to contain p-coumaric acid, ferulic acid and caffeic acid as the major phenolic acids which were isolated using preparative thin layer chromatography. The phenolic acids were characterized using elemental analyses, FT-IR, 1H and 13C NMR spectroscopy. Amides of p-coumaric acid, ferulic acid and caffeic acid were synthesized by their reaction with propyl and butyl amines using microwave irradiation and analysed using spectral studies. Phenolic acids and their amides were evaluated for their effect on pollen germination and tube growth in pumpkin. It was concluded that at 5 ppm concentration, germination percentage and pollen tube growth of p-coumaric acid, caffeic acid and their amides was enhanced than the control. These results could be utilised in increasing pollen tube length of Cucurbita moschata while making interspecific cross between C. moschata and C. pepo in order to transfer the hull-less and disease and virus resistant character of C. moschata to C. pepo.ThesisItem Open Access Synthesis and application of biopolymer hydrogels for seed germination in Calendula(Punjab Agricultural University, Ludhiana, 2021) Sharma, Rupali; Ramandeep KaurRice straw is renewable, non-edible, cost effective and abundantly available feedstock, burning of which leads to emission of hazardous gases, therefore its utilisation is important to reduce extensive atmospheric pollution. The percent composition of rice straw was determined by detergent system method and was found to contain 20.00, 41.00, 24.00, 9.00 and 6.00% extractives, cellulose, hemicellulose, lignin and acid-insoluble ash (silica), respectively. Lignin was extracted by using the dilute acid pretreatment method of rice straw, in which rice straw was treated with 1% H₂SO₄ followed by its alkaline hydrolysis. Lignin was structurally characterized by FT-IR, ¹H and ¹³C NMR spectra. Lignin hydrogels were synthesized using lignin as raw material, poly vinyl alcohol as a matrix template and epichlorohydrin as a crosslinker followed by their characterization using FT-IR and SEM analysis. Different concentrations of lignin hydrogels (0.2%, 0.5%, 0.8% and 1%) were synthesized out of which 0.5% lignin hydrogels proved to be the most efficient due to their high swelling ratio i.e. 130.34 and high reswelling capacity. The dye adsorption capacity of lignin hydrogels came out to be more than that of neat PVA hydrogels. This was followed by evaluation of lignin hydrogels as culture media for seed germination of Calendula. Further, root length, shoot length, root:shoot length, seed vigour index, germination percentage and germination index were noted. It was concluded that 0.5% and 0.8% lignin hydrogels have proved to be efficient as culture media for seed germination of flowering plant Calendula.ThesisItem Open Access Isolation and antifungal evaluation of bioactive compounds from Vinca rosea(Punjab Agricultural University, Ludhiana, 2021) Sharma, Parul; Ramandeep KaurVinca rosea is an evergreen plant belonging to family Apocynaceae possessing numerous medicinal properties. The present work deals with the extraction and chemical investigation of V. rosea leaves and flowers extracts, leaves essential oil and its potential as fungicide against two phytopathogenic wheat fungi i.e., Fusarium graminearum and Bipolaris sorokiniana. Leaves and flowers extracts were prepared using six different solvents. GC-MS analysis of the methanolic extract of leaves revealed tetradec-7-enal (19.61%), glycerol (17.58%) and palmitic acid (16.38%) as the major compounds whereas methanolic extract of flowers showed inositol (42.66%) as the major compound. Quantitative data revealed the presence of alkaloid in higher quantity in leaves. Vindoline, was isolated from the leaves of the plant and other major compounds were isolated by column chromatography from methanolic leaves and flowers extracts. Structures of isolated compounds were elucidated by FT-IR, 1HNMR, 13CNMR and Mass spectroscopic techniques. Fungitoxic activity of V. rosea leaves and flowers extracts, essential oil and isolated compounds was investigated by poisoned food technique at different concentrations (125-1000 µg/ml). Propiconazole (Tilt 25 EC) served as positive control. Methanol extract of leaves and flowers was found to be more effective in comparison to other extract. Among all the tested components, vindoline was observed to be the most active compound against F. graminearum (ED50 = 68 µg/ml) and B. sorokiniana (ED50 = 97 µg/ml). Further the activity was increased with increasing concentration but still less than the synthetic fungicides.ThesisItem Restricted Chemical characterization and insecticidal activity of leaves and flowers of Ageratum conyzoides(Punjab Agricultural University, Ludhiana, 2021) Gurdeep Kaur; Ramandeep KaurAgeratum conyzoides (Asteraceae) is an invasive herb widely distributed in tropical and subtropical parts of the world. The plant is widely studied due to its wide diversity in chemical composition. In the present investigation, the evaluation of insecticidal activity of leaves and flowers of methanol extract and its petroleum ether, chloroform and ethyl acetate fractions were studied against second and fourth instar larvae of Spodoptera litura. The compound βcaryophyllene was isolated from the methanol leaves extract by column chromatography. The larval mortality of both the instars was studied after exposure to various extract and compound at different concentrations (5, 10 and 15%) after regular interval of 24, 48 and 72 h of treatment. It was found that methanol flowers extract exhibited the highest larval mortality of 57.33±0.115% at 15% concentration after 72 h of treatment. Further it was observed that the fourth instar larvae were more susceptible than second instar larvae. Therefore, parameters like consumption index, growth index and morphological deformities were also studied for fourth instar larvae of S. litura. It was observed that the consumption index exhibited a direct relation with concentration and time whereas inverse relation was found with growth index. The lowest consumption index was found in β-caryophyllene (0.030±0.034 mg mg-1day-1) followed by methanol flowers (0.045±0.039 mg mg-1day-1) and methanol leaves (0.057±1.417 mg mg-1day-1) extract. Various morphological deformities in larval and pupal stages were observed. The adults emerged were reduced in size and exhibited wings deformities. Overall, β-caryophyllene exhibited a highest insecticidal activity and has the potential to be developed as botanical pesticide. These findings might have important implications for environment friendly control of pests by using botanical pesticides.ThesisItem Restricted Synthesis and fungicidal activity of 2-aminopyrimidine schiff bases(Punjab Agricultural University, Ludhiana, 2021) Amanpreet Kaur; Sharma, Sunita2-Aminopyrimidines represent an important class of bioactive molecules where its structural changes would lead to its versatile properties. N-Heterocyclic compound i.e. 2aminopyrimidine had wide range of applications in medicinal, material chemistry and agriculture as antifungal, antimicrobial and antibacterial agents. In the present study, a series of substituted N-benzylidine-2-aminopyrimidine compounds were synthesized by condensation reaction of 2-aminopyrimidine with substituted benzaldehydes (o-chloro, mhydroxybenzaldehyde, p-hydroxybenzaldehyde, 2,5-dimethoxybenzaldehyde, pdimethylaminobenzaldehye, syringaldehyde, o-phthaldehyde, isovanillin benzaldehyde, veratraldehyde and thiophene-2-carboxyaldehyde). The synthesised Schiff bases were characterized using UV, IR, 1H NMR and 13C spectral studies. The antifungal activity of all the synthesized Schiff bases was screened against Fusarium verticillioides, Macrophomina phaseolina, and Rhizoctonia solani using poisoned food technique. The Schiff base of pdimethylaminobenzaldehyde and 2-aminopyrimidine showed hundred percent inhibition against all the three fungi but less than carbendazim at 50 WP as its ED50 was less than all the synthesized Schiff bases. Thus, in future, this kind of pyrimidine derivatives may be used to generate better fungicides with improved fungicidal activities.ThesisItem Restricted Adsorption studies on magnesium ferrite-bentonite nanocomposite by linear and nonlinear modeling(Punjab Agricultural University, Ludhiana, 2021) Khushboo; Manpreet KaurThis study envisages the adsorption and photodegradation studies on magnesium ferrite (MgFe2O4)-bentonite nanocomposite by linear and nonlinear modeling, using Cd (II) and martius yellow as model pollutants. The accumulation of MgFe2O4 nanoparticles (NPs) on the bentonite was affirmed by XRD, FT-IR, TEM and SEM-EDS studies. The linear and nonlinear regression methods were employed to accurately predict the adsorption and photodegradation mechanisms. The statistical parameters were evaluated for determining the best-fitted model. Linear type-II Langmuir equation best represented the equilibrium data for Cd (II) ions and martius yellow, which indicated monolayered and physical adsorption. Nanocomposite showed the maximum adsorption capacities of 1073.3 mg g-1 and 789.6 mg g1 for Cd (II) and martius yellow, respectively. The linear pseudo-second-order (type-I) kinetic model gave best-fit for both the adsorption and photodegradation, which specified the interaction of the Cd (II) and martius yellow with two active sites of the adsorbent. The synergistic effect for martius yellow degradation was observed by Cd (II) adsorbed nanocomposite. Degradation pathway was predicted on the basis of quenching studies and GCMS analysis. Thermodynamic studies revealed the endothermic and spontaneous nature of adsorption process. The reusability studies of nanocomposite signified its effectiveness. The present studies demonstrated that among linear and nonlinear modeling, the former fitted well for both adsorption and kinetic studies.ThesisItem Restricted Profiling of Micronutrients and Heavy metals in Ocimum species of Punjab(Punjab Agricultural University, Ludhiana, 2021) Arora, Aayushi; Tandon, RituMedicinal plants are the foundation stones of Ayurveda and Siddha system of medicine as they help in curing a variety of ailments. Genus, Ocimum represents a major member of medicinal plants of family Lamiaceae. Ocimum, also known as Tulsi, is indigenous to the Indian continent and is highly revered for its medicinal uses. Scientific examinations of the medicinal plants w.r.t elemental analysis especially heavy metals are lacking to ensure development of their safe formulations. Such studies are needed to ensure the standardization and quality control of the developed products and approval for use in primary health care. This need has greatly emphasized on the development of analytical methods for their elemental analysis to produce reliable results and hence to guarantee the quality. In present study, ICP-MS method was validated for the simultaneous determination of essential micronutrients (Co, Ni, Se, Cu, Mn, Zn, Al and Fe) and toxic elements (Cr, As, Cd, Pb and Hg) in Ocimum leaves. The extraction of samples was performed by a microwave assisted digestion with HNO3 to stabilize these elements. The validated method fulfilled all the acceptance criteria (Correlation coefficient (R) ≥ 0.995, Recoveries ranging between 70-130 % and RSD ≤ 20 %) for the parameters: linearity, limit of detection/quantification, accuracy and precision at three levels of concentrations. LOQ for all the elements varied from 0.01160.55 µg/kg. Three Ocimum species (Ocimum kilimandscharicum, Ocimum basilicum and Ocimum sanctum) collected from two different locations (PAU, Ludhiana, Punjab and Fragrance and Flavour Development Centre, Kannuaj, Uttar Pradesh) were analyzed for their micronutrient and heavy metal contents by using the validated method on ICP-MS. Analytical results demonstrated that O. kilimandscharicum contained the highest levels of micronutrients especially Fe and Al than other two species. However, among various heavy metals, concentration of Cd (in O. basilicum) and Hg (in all Ocimum species) were found to be higher than their permissible limits of 0.3 and 1.0 mg/kg respectively. The validated method, thus, can be effectively used in laboratory for routine determination of these micronutrients (8) and heavy metals (5) in Ocimum species with acceptable analytical performance.ThesisItem Open Access Dissipation kinetics and leaching potential of pinoxaden in soils of punjab(Punjab Agricultural University, Ludhiana, 2021) Devrath, Anil; Pervinder KaurThe present study investigates the degradation and leaching potential of pinoxaden in soils under laboratory conditions. Soil samples were treated with pinoxaden at application rates of 25, 50, 100 and 150 g ha-1. Soil type, application rate and temperature had a great influence on degradation rate of pinoxaden. Pinoxaden residues were extracted by ultrasonic assisted extraction (UAE) and salting out liquid liquid extraction (SALLE) from soil and water, respectively and quantified using HPLC-UV. Average recoveries of pinoxaden ranged from 84.9 to 102.6% and 86.6 to 103.9% from soil and water, respectively. Limit of detection (LOD) and limit of quantification (LOQ) were 0.0026 µg mL-1 and 0.008 µg mL-1, respectively. Degradation of pinoxaden followed first order kinetics with half- lives varying from 51.09 to 66.98 hours in studied soils. Degradation increased with increase in temperature and varied from 51.09 to 63.38, 41.18 to 66.98 and 22.85 to 55.72 hours at 5±2, 15±2 and 25±2°C, respectively. Leaching potential of pinoxaden was investigated in loamy sand, sandy loam and clay loam at application rates of 25, 50, 100 and 150 g ha-1 with rainfall equivalent to 150 and 300 mm. No residues of pinoxaden were detected from the different depths at 25 and 50 g ha-1 in loamy sand, sandy loam and clay loam soil at 150 and 300 mm rainfall simulation. However, residues of pinoxaden at higher application rates 100 and 150 g ha-1 varied from 0.011 to 0.015 and 0.012 to 0.016 μg g ha-1 at 150 and 300 mm simulated rainfall. Pinoxaden was not detected in leachates collected from soil columns at 150 and 300 mm simulated rainfall.ThesisItem Open Access Dissipation kinetics of imazethapyr and its effect on soil enzymes(Punjab Agricultural University, Ludhiana, 2020) Lovedeep Kaur; Pervinder KaurFate of herbicide in soil is greatly affected by several factors viz. soil properties, temperature, and application rate. The present study assesses the degradation dynamics of imazethapyr in soils of Punjab under laboratory conditions. The dissipation of imazethapyr followed biphasic first order kinetics and soil type, application rate and temperature greatly influenced the dissipation behavior of imazethapyr. The half-life of imazethapyr for the first relatively faster phase was 5.87 to 7.47 days and it ranged from 76.50 to138.68 days in second relatively slower phase in studied soils. The adsorptive potential was probably responsible for the difference in dissipation rate between the studied soils. Degradation rate of imazethapyr increased with temperature and its half life ranged from 76.50 to138.68, 79.44 to 142.92 and 83.31 to 145.09 days at 25, 35 and 45°C. The presence of imazethapyr metabolites was also detected in studied soils using LC-MS/MS. Imazethapyr get degraded into three metabolites which ultimately get mineralized to carbon dioxide as end product. Variation in physicochemical properties of soils and applied herbicide changed the period of appearance and persistence of the metabolites. Imazethapyr application has short lived as well as transitory effect on dehydrogenase activity (DHA), alkaline phosphates activity (APA) and soil microbial biomass at all application levels but urease activity remains unaffected.
