Loading...
Thesis
Browse
6 results
Search Results
ThesisItem Embargo Synthesis of boron and phosphorous doped graphene fabricated with magnesium ferrite – bentonite nanocomposite for the remediation of pollutants(Punjab Agricultural University, 2022) Manpreet Kaur; Manpreet KaurGraphene oxide (GO) doped with heteroatoms are gaining interest in depollution of water because of their large surface area. The boron-doped GO (B-GO), phosphorous-doped GO (P-GO) and boron and phosphorous co-doped GO (BPGO) in different w:w ratios were synthesized and fully characterized using analytical techniques viz. FT-IR, XRD, SEM-EDS, TEM, BET, Mössbauer and XPS. In order to impart magnetic features to doped GO materials, magnesium ferrite-bentonite (MGF-B) was used to fabricate nanocomposite of MGF-B and BPGO having hierarchical nanoflowers like morphology (HNFs). TEM of co-doped GO showed more wrinkled surface than doped GO, whereas in case of HNFs, chiffon-like BPGO nanosheets were wrapped on the MGF-B surface, resulting in a porous flower-like morphology. The synthesized materials were explored as adsorbents for the removal of Pb(II) and As(III) ions and as photocatalysts for the degradation of martius yellow, p-nitrophenol and malathion from synthetic waste water. The trend for the percentage removal of heavy metals by adsorption and degradation of organic pollutants by photocatalysis in the descending order was found to be: HNFs > BPGO-1:1 > BPGO-1:5 > BPGO-1:0.2 > MGF-B > P-GO > B-GO > GO. The adsorptive and photocatalytic potential of HNFs was greater as compared to pristine, doped and codoped GO due to high surface area, remarkable charge transfer ability and layered structure of codoped GO sheets. The HNFs possessed appreciable saturation magnetization than doped and co-doped GO layers, which led to its easy separation and reusability. Box-Behnken design was utilized for exploring the simultaneous effects of the independent variables on removal of metal ions and degradation of organic pollutants (as dependent variable) using HNFs. The adsorption and photocatalytic mechanism was proposed on the basis of adsorption isotherm, thermodynamic, kinetic and quenching studies. Enhanced activity of HNFs with adsorption of heavy metal could be defined by the electronic structural properties of elements. The best adsorbent and photocatalyst were also tested for spiked solution containing different metal ions and real life industrial water matrices.ThesisItem Open Access Computation and validation of different agroclimatic indices for wheat(Punjab Agricultural University, Ludhiana, 2023) Manpreet Kaur; Dhaliwal, L.K.The field experiment was conducted at the Research Farm, Department of Climate Change and Agricultural Meteorology, Punjab Agricultural University, Ludhiana during rabi season of 2021-22. The wheat varieties viz., PBW 1 Zn, PBW 725, Unnat PBW 343 and PBW 752 were sown on October 26, November 8, November 16 and November 23. The crop was sown in Randomised complete block design with four replications. The recommended Package of Practices by PAU were followed for raising the crop. The micrometeorological parameters viz. photosynthetically active radiation (PAR), canopy temperature and relative humidity within canopy were recorded at periodic intervals. Biometric observations such as leaf area index (LAI) and dry matter accumulation (DMA) were recorded periodically. The yield and yield contributing characteristics were recorded at the time of harvesting. The wheat yield data of Ludhiana district from 2000-2001 to 2021-22 were collected and corresponding meteorological data on different parameters were obtained from Agrometeorological Observatory. Different agroclimatic indices viz., growing degree days, heliothermal units, photo-thermal units, pheno-thermal index, hygro-thermal units and relative temperature disparity were computed at different phenological stages. Heat use efficiency, helio-thermal use efficiency, photo-thermal use efficiency and radiation use efficiency were computed during rabi 2021-22. The results indicates that growing degree days, photo-thermal units, hygro-thermal units and relative temperature disparity were higher in October 26 sowing as compared to November 23 sowing. Whereas, helio-thermal units were higher in November 23 sowing. Heat use efficiency, helio-thermal use efficiency and photo-thermal use efficiency were higher in October 26 sown crop as compared to November 23 sown crop for total biomass and grain yield.The results showed that crop sown on November 23 experienced higher canopy temperature at reproductive stages as compared to October 26 sown crop. The grain yield was significantly higher in October 26 sowing (44.3 q ha-1) as compared to November 23 (39.2q ha-1) for variety Unnat PBW 343. Historical data on wheat yield and meteorological parameters were analysed from 2002-03 to 2021-22. The extreme heat wave years (2003-04, 2008-09 and 2021-22) indicates that maximum and minimum temperatures were higher than normal by 4 to 5°C during reproductive stage and no rainfall due to absence of western disturbances in the month of February and March was responsible for yield reduction. Temperature condition index was lower at reproductive phase and positively correlated with grain yield. Lower the values of temperature condition index, higher was the stress condition in the wheat crop and viceversa. The crop remained under stress in October 26 and November 8 sowing for 45 days whereas for November 16 and November 23 remained for 60 days. It means that late sown crop (November 16 and November 23) faced stress at heading stage and remained under stress for longer period as compared to early sowing (October 26 and November 8) which faced the moderate stress at anthesis stage.ThesisItem Restricted Promoter polymorphism and development of molecular markers for FAD2 genes associated with oleic acid content in Brassica juncea L.(Punjab Agricultural University, 2023) Manpreet Kaur; SunayanaThis study was undertaken to investigate the functional copies of the FAD2 gene that contribute to the formation of high oleic acid through expression profiling in low and high oleic acid groups of B. juncea. Subsequently, the promoter region of the functional FAD2 gene was extracted and analysed to identify sequence variations within both LOA and HOA groups using multiple sequence alignment. Molecular markers were developed using the identified variability in the promoter region and then validated on the F2 population derived from the cross between LOA (RLC3) and HOA (HOJ 93-1) cultivars. Three distinct functional copies of the FAD2 gene are situated on chromosomes A05 (BjuA.FAD2.a2), B01(BjuB.FAD2.b1) and B05 (BjuB.FAD2.b2) in B. juncea. The gene expression of BjuA.FAD2.a2 and BjuB.FAD2.b2 exhibited a higher fold change value in comparison to low and high oleic acid genotypes. The expression of BjuB.FAD2.b1 gene has an almost similar expression in diverse oleic acid genotypes. For the functional characterization of the promoter region of the FAD2 gene HOJ 93-6, HOJ 93-1 and RLC3, having high and low oleic acid content were outsourced for re-sequencing. Multiple sequence alignment indicated nucleotide variation only for BjuA.FAD2.a2 and BjuB.FAD2.b1 gene. No nucleotide variation was detected within BjuB.FAD2.b2 gene. SSR and CAPS makers were designed to facilitate marker assisted selection for high oleic acid content. After the validation of markers on parents and the F2 population, three distinct classes were observed for inheritance studies. The first category was characterized by oleic acid content exceeding 58%, the second displayed intermediate oleic acid levels of 46-56% and the third category exhibited low oleic acid content ranging from 40% to 45%. Inheritance studies indicated that the regulation of oleic acid content was governed by two FAD2 gene copies which are present at the A05 and B01 chromosome.ThesisItem Embargo Assessment of Salix clones for morphological and physiological traits under salt stress(Punjab Agricultural University, Ludhiana, 2022) Manpreet Kaur; Thakur, SapnaThe present investigation entitled “Assessment of Salix clones for morphological and physiological traits under salt stress” was carried out in the teaching area, Department of Forestry and Natural Resources, Punjab Agricultural University, Ludhiana, Punjab during the year, 2021. Stem cuttings of selected five Salix clones were established in a pot experiment in Feb, 2021 arranged in Factorial Completely Randomized Design (CRD) using four replications and were irrigated with 0, 20, 40, 60, 80mM NaCl treatments for the active growth period. The observations on growth and physiological characteristics of clones as well as chemical parameters of soil were recorded at an interval of two months after initiation of salinity treatments i.e., May, July and October. However, the biomass parameters were recorded at the end of experiment. All the growth and biomass traits showed significantly reduction with increase in salinity treatments. Among physiological traits, significant reduction were observed in total chlorophyll, carotenoids, total starch and relative water content, while salinity stress raised the content of proline, total soluble sugar, total soluble protein, total phenol, electrolyte leakage and Na+/K+ ratio in all the clones. The enzymatic activities of POD and SOD increased in all the clones when subjected to higher levels of salinity stress. On the basis of overall mean performance, clone UHF 03 showed better growth and biomass accumulation at 80 mM and was found to be the most tolerant to salinity stress among tested clones. SEM and EDS mapping confirmed anatomical changes and higher Na accumulations in the roots and leaves of Salix in response to salinity stress. Highest heritability and genetic gain were recorded for relative water content, POD, fresh root weight, dry root weight and proline content. Strong correlation was observed for total dry weight with various physiological traits i.e., total starch, relative water content, total chlorophyll, carotenoids, total phenol, electrolyte leakage, Na+/K+ ratio, SOD and POD and thus, these traits must be given due importance while making selection for salt tolerance in Salix species.ThesisItem Restricted Mapping and transfer of higher grain length and multiple rust resistance from T.dicoccoides to cultivated wheat(Punjab Agricultural University, Ludhiana, 2022) Manpreet Kaur; Satinder KaurWild emmer wheat, Triticum dicoccoides, the progenitor of modern tetraploid and hexaploid wheats, is an important resource of new variability for disease resistance genes and grain yield traits. T.dicoccoides acc. pau14723 showed resistant to leaf and stripe rust races and was crossed with T.dicoccoides acc. pau4663 (susceptible to leaf and stripe rust) for studying the inheritance and mapping the genes for leaf and stripe rust resistance. Recombinant inbred lines were developed and screened against highly virulent Pt and Pst pathotypes at the seedling and adult plant stages. Inheritance analyses revealed that both the rust infections were controlled by dominant major single gene. For mapping these genes, the markers showing diagnostic polymorphism in the resistant and susceptible bulks were amplified on all RILs. The molecular characterization identified the genes to be present on 1A chromosome of wheat (short arm). MapDisto version 1.7.5. Beta 4 software was used to determining the linkage present between the genes governing resistance and the SSR markers Xbarc148, Xbarc240, Xwmc93, Xwmc818. A total map size of 9.7cM was obtained showing no segregation between Lr and Yr genes and the marker lying closest to the resistance genes was Xbarc148 at 1 cM distance from the resistance genes. The variation in the T. dicoccoides for the yield related traits was studied by crossing the accessions having longer and wider grains with the accessions having shorter grains resulting in three different crosses: T.dico.14723 and T.dico. 4663, T.dico.5219 x T.dico. 4663 and T.dico. TA1027 x T.dico. 5232. The RIL populations developed from these crosses were screened for different traits affecting the yield which include 100 grain wt. (100 Gwt.), spike length (SpL), spike length with awns (SpLWA), no. of spikelets/spike (Splts/Sp), grain length (GL), grain width (GW) and grain area (GA). The interaction between the traits and their contribution to grain yield was studied. The molecular and the phenotypic data was statistically analyzed for the significant contribution of marker alleles. The evaluation of allelic effects of the polymorphic markers for each trait using Kruskal–Wallis test showed that the phenotypic differences in the mean value of GL, GA and GWT were statistically significant for the three different classes of TaGASR7-A and TaGASR7-D. The study suggests the use of variation existing in T.dicoccoides germplasm for wheat breeding programmes.ThesisItem Open Access Effect of surface coatings and neem extract on post-harvest life and quality of Kinnow fruits under low temperature storage(Punjab Agricultural University, Ludhiana, 2022) Manpreet Kaur; Gupta, NavjotPresent study entitled “Effect of surface coatings and neem extract on post-harvest life and quality of Kinnow fruits under low temperature storage” was conducted at Department of Fruit Science, Punjab Agricultural University, Ludhiana during the year 2020-21. The fruits of Kinnow were coated with sodium alginate (2%), aloe vera gel (50%), neem leaf extract (10%, 20% and 40%) and their various combinations and packed in corrugated fibre board (CFB) boxes (5% perforation) with paper lining before storage at 5-6oC and 90-95% RH for 75 days. Fruits were analyzed for various physical and biochemical parameters at 30, 45, 60 and 75 days interval. Results revealed that the physiological loss in weight and spoilage increased progressively with the advancement of storage period. Fruit juice content, peel thickness, titratable acidity, vitamin C content, carotenoid content, total phenol content, total flavonoid content, DPPH antioxidant activity and hydroxyl radical scavenging activity of Kinnow fruits showed a declining trend with the progression of storage period being the lowest in fruits kept under control. Whereas, TSS and sugars exhibited an initial increase in all the coated fruits during storage followed by a decreasing trend towards the end of storage period. However, the rate of increase in TSS and sugars during the initial stages of storage and later decrease was found to be higher in the untreated fruits. Fruits coated with 2% sodium alginate or 50% aloe vera gel in combination with 20% or 10% neem leaf extract or 50% aloe vera gel alone were found to be moderately to slightly desirable upto 75 days of storage. Among all the treatments, combined coatings of 2% sodium alginate + 20% neem leaf extract and 50% aloe vera gel + 20% neem leaf extract proved to be the most effective in extending storage life of Kinnow under low temperature storage conditions by reducing the physiological loss in weight and spoilage and maintaining higher content of juice, titratable acidity, vitamin C, carotenoid content, total phenol content, total flavonoid content, DPPH antioxidant activity and hydroxyl radical scavenging activity during storage.
