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ThesisItem Open Access Effect of inorganic fertilizers and bioinoculants on biochemical components, growth, yield of garlic (Allium Sativum L.) and nutrient status of soil(Punjab Agricultural University, Ludhiana, 2021) Mamta; Sharma, RajniGarlic (Allium sativum L.) is an economically important vegetable crop which is used worldwide for culinary and medicinal purposes. The present study was conducted on garlic variety “PG-18” in a randomized block design during 2019- 2020. There were nine treatments which included various percentages of inorganic fertilizers (100% NPK, 75% NPK and 50% NPK) in combination with bioinoculants (consortium I and consortium II). Results reveals that supplementation of 75% NPK along with bioinoculants (consortium I or consortium II) gave the superior results than control (100% NPK) for most of traits such as plant growth parameters (plant height, leaf length, leaf width, pseudostem length and bulb diameter), yield attributes (total yield, marketable yield, 50 cloves weight and number of cloves) and biochemical parameters (total soluble sugars, reducing sugars, total phenols and total soluble solids). Moreover, nutrient content (nitrogen, phosphorus and potassium) of leaves and bulbs of garlic increased by combined inoculation of different combinations of NPK along with bioinoculants. Integrated application of inorganic fertilizers along with bioinoculants improved soil’s physico-chemical (pH and organic carbon) and biological (dehydrogenase activity) properties. Most of the parameters i.e. plant growth, total yield, nutrient, biochemical and soil properties decreased when the dose of 50% NPK supplemented with bioinoculants. Therefore, it can be concluded that integrated utilization of these bioinoculants along with 75% NPK improves soil health and it also offers scope of reducing the application of inorganic fertilizers to garlic crop by 25% without any loss in bulb yield.ThesisItem Open Access EVALUATION OF MORPHO-PHYSIOLOGICAL AND METAL ACCUMULATION POTENTIAL OF Salix alba L. AND Toona ciliata M. Roemer GROWN ON HEAVY METAL CONTAMINATED SOILS(Punjab Agricultural University, Ludhiana, 2022) Ravneet Kaur; Sharma, RajniThe present investigations were carried out to study the effect of lead (Pb), cadmium (Cd) and their combinations (Pb+Cd) on morpho-physiological and metal ccumulation potential of Salix alba and Toona ciliata during 2020 and 2021. Heavy metals induce negative effect on morphological and biomass attributes of both species, but Toona showed better survival percentage (>95%) than Salix (1, TF1 and TF>1). Further, heavy metal translocation and accumulation decreased in combinations as compared to single element application suggesting the antagonistic relationship among both metals. Pb and Cd negatively affect the plant nutrient content either by affecting their translocation or by decreasing nutrient availability in soils. Anatomical studies showed significant alterations in stomatal pore size, stomatal density and trichome density due to heavy metal toxicity in both Salix and Toona. Field emission scanning electron microscopy and energy dispersive x-ray spectroscopy (FESEM-EDS) results confirmed the Pb and Cd accumulation sites in the leaves and root tissues of plants. Fourier transformed infrared (FTIR) spectroscopy analysis revealed that Pb and Cd accumulation in plants induced changes in carboxy, amino, hydroxyl and phosphate groups that ultimately caused alteration in physiological functioning in plants. Conclusively, both Salix alba and Toona ciliata have potential to be used as remediation species for Pb and Cd contaminated soils.ThesisItem Embargo Mitigation of salt stress by γ-amino butyric acid (GABA) and proline in maize (Zea mays L.)(Punjab Agricultural University, Ludhiana, 2022) Sharma, Sakshi; Gupta, NamartaThe present investigation was conducted to study the effect of proline and GABA on physiological and biochemical parameters at different on different salt stress levels in two varieties of J-1006 and J-1007 maize (Zea mays). The salt stress negatively affected the seed germination and seed vigour parameters. Seeds of both the varieties were subjected to different treatments viz. Proline (10mM and 20 mM) and GABA (100ppm and 500ppm) at salt stress level of 50mM, 75mM and 100mM NaCl. Various parameters were recorded from seedlings after 10 days of germination. The seed treatments positively affected the physiological parameters (percentage germination, seedling length, seedling biomass, seed vigour I and seed vigour II) and biochemical parameters (total soluble sugars, total soluble protein and activities of antioxidant enzymes viz. Catalase, peroxidase and superoxide dismutase) of treated seedlings as compared to control. However, a reduction was observed in malondialdehyde content continue to decreased with seed treatments at all salinity levels. The results recoded that proline 20mM and GABA 500 ppm were more effective than proline 10mM and GABA 500ppm respectively. Therefore, the application of seed treatments viz, proline and GABA could play an important role in mitigating the effect of salt stress.ThesisItem Embargo Mechanism of salinity tolerance in elite wheat (Triticum aestivum L.) germplasm(Punjab Agricultural University, Ludhiana, 2023) Choudhary, Anuj; Nirmaljit KaurThe current research work on “Mechanism of salinity tolerance in elite wheat (Triticum aestivum L.) germplasm” was conducted to illuminate the genetic potential of wheat lines for salt stress tolerance. The study was undertaken at the laboratory and experimental area of Department of Botany and Department of Plant Breeding & Genetics, Punjab Agricultural University, Ludhiana during 2018-19 and 2019-20. A set of 278 wheat lines was procured from Department of Plant Breeding & Genetics was initially screened under lab condition. Selected lines were subjected to various salt stress concentrations viz. 0 mM, 30 mM, 60 mM, 90 mM, 120 mM, 150 mM and 180 mM NaCl. It was followed by screening of all wheat lines at standardized 150 mM salt stress condition for shoot length, root length, shoot fresh weight, root fresh weight, shoot dry weight, root dry weight and vigor index. They were grouped as 11 highly salt tolerant, 57 salt tolerant, 89 moderately salt tolerant, 116 salt sensitive and 5 highly salt sensitive. Twenty lines were selected for precise evaluation under the naturally salt affected field conditions and the controlled condition on the basis of morphological, physiological and yield attributes. The EC value of the controlled plots ranged between 0.41 to 0.81 m mhos cm-1 whereas the EC value of saline plots was between 0.79 and 1.71 m mhos cm-1. Among the 20 wheat lines, the LTP 187 (linked top cross population), LTP 210, and LTP 221 performed better for all the traits under field conditions and therefore, these are suggested for the future wheat breeding improvement programs for salt stress. Three SNPs (SNP_986175, SNP_ 2264905 and SNP_4910157) were found significantly associated with salt stress. Significantly associated SNPs were mainly observed on chromosomes 1A, 1B, 3A, 3B, 5A, 5B, 6B, 7A and 7D and therefore these SNPs can be used in marker assisted breeding programs for improving thousand grain weight in wheat.ThesisItem Open Access Amelioration of terminal heat stress in wheat through exogenous application of stress protectants(Punjab Agricultural University, Ludhiana, 2021) Kirti; Gupta, NehaThe present investigation entitled "Amelioration of terminal heat stress in wheat through exogenous application of stress protectants” was conducted at the Wheat Experimental Area (30º56’N and 75º52’ E, 247 m ASL), Dept. of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana during the Rabi seasons of 2019-20 and 2020-21. The field experiment was conducted in split-split plot design with sowing date as main plot and wheat varieties (PBW 771 and PBW 725) as sub plot treatment. The crop was sown at two sowing dates i.e Nov. 5 and Dec. 5 in which late sown crop was exposed to terminal heat stressed condition. The wheat cultivars PBW 771 and PBW 725 were used in study. The exogenous spray of stress protectants acted as sub-sub plots. These foliar treatment of stress protectants given were control (water spray), 50µM melatonin, 100µM melatonin and 2% KNO3. Present study depicted a significant difference in seedling emergence with date of sowing; where timely sown exhibited higher germination and better emergence than late sown crop. Non-significant differences in NDVI and CTD at 60 DAS. At 90 DAS, 100μM melatonin treated plots showed increased NDVI and decreased CTD values than other stress protectants. Among various biochemical traits (viz. chlorophyll content, lipid peroxidation etc.) late sown crop depicted higher membrane instability by increased electrolyte leakage, lipid peroxidation and DPPH radical scavenging activity, While application of 100µM melatonin were found to be significantly effective in accumulation of total soluble sugars, melatonin, retention of photosynthetic pigments (chlorophyll and carotenoid), pollen viability % and improved membrane thermo-stability by decreasing electrolyte leakage, lipid peroxidation and increasing DPPH radical scavenging activity. Different yield attributes (viz. tiller/m2, no. of spikelets per spike, thousand grain weight, harvest index, grain yield etc.) were found to be affected significantly with delay in sowing of the wheat. A significant effect of sowing date on grain yield was observed where late sown crop had 35.28% and 16.75% reduction in grain yield during 2019-20 and 2020-21.Application of 100µM melatonin was found to ameliorate negative effects of late sown crop under terminal heat stress significantly resulting in increased no. of tiller/m2, effective tiller/m2, no. of spikelets per spike, no. of grains per spikelet, thousand grain weight, biological yield, harvest index and no. of grains per spike. Thus, application of 100µM melatonin improved the yield significantly than other stress protectants under terminal heat stress conditions. Sowing time also affected quality traits like grain hardness, percent protein and gluten index significantly in our study. Application of 100µM melatonin was also found to be effective in improving wheat quality traits.ThesisItem Open Access Effect of salt stress on physiological, biochemical and gene expression level in different genotypes of sorghum (Sorghum Bicolor L.)(Punjab Agricultural University, Ludhiana, 2022) Manjeet Kaur; Gupta, NamartaThe present study was undertaken to assess the effect of salt stress using different NaCl concentrations (0, 25, 75, 100, 125, 150, 175 and 200mM) on the physiological, biochemical, morphological and quality traits in twenty sorghum genotypes (SSG-59-3, ICSV2077A, HC308, PSC1, ICSV94001, ICSV94002, ICSV94012, ICSV94031, ICSV94056, NSS1002, NSS1003, SCL1, SCL2, PSC4 SL44, CSV24SS, AKMS27, CSV19SS, NSS1005 and SGL87). The expression of salt responsive genes was also studied. Increase in salt stress caused a significant reduction in germination percent, germination speed, seedling length, biomass and seedling vigour index. Based on the various physiological parameters, the genotypes were categorized into salt tolerant, moderately tolerant, moderately susceptible and susceptible ones. The effect was more differentiable at 50mM, 75mM and 100mM of NaCl. Therefore, these salt levels were selected to test their effect on biochemical parameters. The biochemical parameters, suitable markers of salt stress viz., total soluble sugars, total soluble proteins, proline content and activity of antioxidant enzymes (superoxide dismutase, peroxidase and ascorbate peroxidase) increased with increase in salt stress levels and the effect was more pronounced in tolerant genotypes as compared to susceptible ones. Proline content showed negative correlation with lipid peroxidation (H2O2 content) and malondialdehyde content. Moreover, the effect of salt stress was also studied on morphophysiological (leaf area, chlorophyll content, carotenoid content, membrane stability index) and quality traits (CP, IVDMD, ADF, NDF and HCN content) at two locations (Ludhiana and Ratta Khera). Soil of Ratta Khera (Sh. Muktsar) was salt affected and soil of Ludhiana (PAU) was considered as control. Leaf area, chlorophyll and carotenoid content, membrane stability index, CP and IVDMD decreased significantly in salt stressed plants at Ratta Khera as compared to control plants at PAU, while ADF, NDF and HCN showed antagonistic results. Further, transcript profiling was conducted in two salt-tolerant (SSG-59-3, HC308) and two salt-sensitive genotypes (SGL87, NSS1005). The expression of salt responsive genes viz., SbSOS1, SbNHX3 and SbHKT(1;4) increased higher fold in tolerant genotypes as compared to sensitive ones.ThesisItem Open Access Variation for coleoptile length and emergence traits in wheat (Triticum aestivum L.)(Punjab Agricultural University, Ludhiana, 2021) Sharma, Tanvi; Goyal, PrinkaWheat sowing with happy seeder usually suffers reduced germination to variable extent in rice-wheat cropping system (RWCS), Reduced germination is usually due to slow emergence of seedlings owing to load of rice straw as well as high temperature stress due to early sowing of wheat. This study was designed to study genotypic variance for coleoptile length and further, identify the genotypes with longer coleoptile at high temperature, ultimately resulting in early, ensured and uniform seedling emergence. The genotypes were tested in field with deep as well as with happy seeder sowing for various morphological, phenological and yield attributes. Laboratory experiment was set up in customized random design while the field trial was sown in randomized block design with three replications. HD 2967 showed an increment in coleoptile length at higher temperature accompanied with early emergence in the field conditions. Genotypes BWL 5485, BWL 5488 and DBW 90, in spite of having short coleoptile length, showed early emergence under happy seeder sowing and exhibited better morphological, phenological and yield parameters as compared to normal and deep sown wheat which can be attributed to the presence of high moisture content. The correlation between coleoptile length and days taken to emergence was perfectly negative linear in deep sown wheat (r= -0.22, p<0.01%) but weak in normal (r= 0.15) and happy seeder sown wheat (r= 0.27). Days taken to heading and maturity, length of first internode in normal and deep sown wheat was at par with each other while it increased for happy seeder sown wheat. Similarly, 1000-grain weight and grain yield of happy seeder sown wheat showed an increment (56.60g, 384.53g respectively) while the same traits for normal (53.39g, 255.21g) and deep sown wheat (51.42g, 249.57g) was at par with each other respectively. The identified genotypes can be used as donors in wheat breeding programs to mobilize this useful train in elite agronomic and advance breeding lines.ThesisItem Open Access Investigation of physiological and biochemical mechanisms of cold tolerance in chickpea(Punjab Agricultural University, Ludhiana, 2021) Amandeep Kaur; Gupta, NehaThe present study entitled “Investigation of physiological and biochemical mechanisms of cold tolerance in chickpea” was undertaken in the Experimental area of Department of Plant Breeding and Genetics, PAU, Ludhiana during consecutive years of 2019-20 and 2020-21. The plant material involved in study was thirteen advanced lines and three cultivars (GPF-2, PBG-5, and PBG-7) of chickpea which were exposed to cold stress at reproductive stage under field conditions. Various physiological and biochemical parameters such as proline, electrolyte leakage, photosynthetic pigments, lipid peroxidation etc. were measured before and after exposure to cold to delineate the mechanism of tolerance in these genotypes. Significant genotypic variations were found for the above-mentioned traits in present study for the both the years. However, contents of proline, chlorophyll, carotenoids and radical scavenging activity was significantly higher in tolerant line GL29183. Similar trend of increment in pollination potential was observed in GL29183 where pollen viability and pollen load were maximum but statistically at par to check cultivar PBG5. Genotypic variations were also significant for studied phenology and yield contributing parameters. The tolerant line GL29183 produced significantly higher flowers/plant, pods/plant and maximum pod fertility score. Further, increase in number of seeded pods contribute to better productivity and maximum yield/ plant in GL29183 especially GL29183-P2 among advanced lines. Higher number of days to 50% flowering and flowering duration was reported in GL27059-P2 than other advanced lines. However, susceptible genotype GL28202 performed poorly in traits pods plant -1 with minimum pollen viability percentage and pollen load reflecting the differential reproductive tolerance of studied genotypes. The biochemical studies depicted highest electrolyte leakage in genotypes GL28203-P3 and GL28008-P2 which was statistically at par to GL28202 (P1, P2). The seed quality attributes revealed that GL29183 line had greater seed size as comparative to other advanced lines. The percentage protein content was also at par to GL28202-P2. The sugar content was found to be similar in advanced lines and check cultivars. Our study depicted that among the advanced lines, GL29183-P2 was tolerant to early cold stress at reproductive stage.ThesisItem Open Access Improving seed longevity of maize (Zea mays L.) through desiccation and packaging materials(Punjab Agricultural University, Ludhiana, 2021) Sukhpreet Kaur; Navjyot KaurThe present study entitled “Improving seed longevity of maize (Zea mays L.) through desiccation and packaging materials” was conducted during 2020-21. The seeds collected four months after harvest were desiccated to different moisture levels i.e., 12, 10 and 8% followed by storage in different packaging bags viz., laminated polypropylene bags, non- aminated polypropylene bags and polyethylene bags. Seeds with 12% moisture content stored in cloth bags served as control. Seeds of different treatments were stored under ambient conditions for 12 months. Physiological parameters were observed at monthly intervals and biochemical parameters were observed at three months interval during storage period. Germination percentage, seedling dry weight, seedling vigour index I and II and speed of germination decreased with increase in storage period; whereas electrical conductivity and mean germination time recorded a gradual increase with increased storage duration irrespective of different seed storage treatments. It was observed that seeds stored in laminated polypropylene bags and non-laminated polypropylene bags, polyethylene bags as well as cloth bags maintained the germination above 90% up to 13 months and thus complied IMSCS. Gradual decrease in germination was recorded with increase in seed storage duration and no seed storage treatment could maintain germination above IMSCS after 13 months of seed storage. The seed moisture content recorded fluctuations in accordance with relative humidity present in environment in all the packaging materials but greater fluctuation was observed in seeds stored in cloth bags and polypropylene bags as compared to seeds stored in polyethylene bags. Various food reserves viz., sucrose, starch content, oil and total soluble proteins decreased with increase in storage period; while total free amino acids increased with increase in seed storage duration. There was gradual decrease in α-amylase activity with increase in seed storage duration irrespective of the seed storage treatments. Antioxidant enzymes viz., superoxide dismutase, catalase and peroxidase also recorded gradual decrease in their activities in all the packaging materials with increased seed storage duration. Protein profiling indicated that the intensity of electrophoretic bands corresponding to polypeptides of molecular weight 44 and 52 kDa was higher in fresh seeds as compared to 15 months old seeds stored in various packaging treatments. The present study suggests that polypropylene bags either laminated or non-laminated can be used as cost effective and durable packaging materials instead of cloth bags and polyethylene bags owing to their lesser cost and higher flexural strength.
