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2022 - 20234
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Author: Manpreet Kaur × Start date: 2022 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen 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.
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    ThesisItemRestricted
    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; Sunayana
    This 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.
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    ThesisItemEmbargo
    Assessment of Salix clones for morphological and physiological traits under salt stress
    (Punjab Agricultural University, Ludhiana, 2022) Manpreet Kaur; Thakur, Sapna
    The 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.
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    ThesisItemOpen 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, Navjot
    Present 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.