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20222
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Author: Manpreet Kaur × End date: 2022 × Start date: 2022 × Thesis Type: M.Sc ×
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    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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    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.