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ThesisItem Open Access Evaluation of flag leaf characteristics in relation to spike quality and corm production in gladiolus (Gladiolus grandiflorus L.)(Punjab Agricultural University, 2024) Ramandeep Kaur; Dr. Shalini JhanjiThe present investigation entitled “Evaluation of flag leaf characteristics in relation to spike quality and corm production in gladiolus (Gladiolus grandiflorus L.) was conducted at the Research Farm of the Department of Floriculture and Landscaping, Punjab Agricultural University, Ludhiana during 2022-2023. The genotypes/varieties were evaluated for distinctiveness, uniformity and stability (DUS). Significant differences among the genotypes were recorded for studied morphological and post harvest quality parameters. The cluster analysis grouped the genotypes/varieties into two major clusters which were further subdivided into two subclusters each. Cluster Ib (Punjab Pink Elegance, Punjab Lemon Delight, Punjab Glance, etc) performed best in terms of desirable morphological traits while cluster IIa (Pusa Gunjan, Pusa Kiran, Punjab Dawn, etc) was found to have performed least in terms of various morphological characters. Cluster analysis also revealed that Punjab Glance and Punjab Glad 3 lied in different clusters and differed based on flag leaf length, spike length, spike weight, corm weight, days to initiation and complete spike emergence due to which these two varieties were selected for evaluation of flag leaf characteristics in relation to spike and corm production during different spike developmental stages. With advancement in developmental stages, there was significant growth of flag leaf, spike and corm. In comparison of Punjab Glance and Punjab Glad 3, Punjab Glad 3 had comparatively greater flag leaf length, width, area, weight, total leaf weight, area, spike length, rachis length, spike weight, rachis weight, spike diameter, lamina thickness, epidermal thickness, mesophyll thickness and stomatal index but in terms of corm traits, Punjab Glance had greater number of corms, corm weight, corm diameter and number of cormels. Punjab Glad 3 had comparatively greater membrane stability (MS), relative water content (RWC), total soluble sugars (TSS), total soluble proteins (TSP), sucrose content, starch content, activity of acid invertase, neutral invertase and sucrose synthase than Punjab Glance in both flag leaf and spike while in corm Punjab Glance had greater MS, RWC, TSS, TSP, sucrose content, starch content, activity of acid invertase, neutral invertase and sucrose synthase. Punjab Glad 3 had greater flag leaf length and width which led to longer spike but less corm development as maximum assimilates were translocated to spike while in case of Punjab Glance though it had shorter spike but the corm in this case had greater sink strength which led to better corm development.ThesisItem Restricted Effect of foliar application of humic acid against terminal heat stress in wheat (Triticum aestivum L.) genotypes(Punjab Agricultural University, 2023) Aishwarya Rawal; Aparjot KaurTerminal heat stress in wheat (Triticum aestivum L.) is a major threat on account of global climate change that significantly affects the yield. To investigate the present study, wheat varieties viz PBW 725 (timely sown) and PBW 752 (late sown) were sown in randomised block design as per PAU‟s package and practice in PVC cylinders (PAU) and field (RRS, Bathinda) conditions. Foliar application of two concentration of humic acid (2000 ppm and 4000 ppm) was done ten days prior to tillering, booting and flowering stage. The treatment without any spray served as control. At all stages morpho- physiological and biochemical parameters were recorded whereas yield and yield attributes were recorded at maturity. The present study found that foliar spray of 2000 ppm and 4000 ppm humic acid significantly increased plant height in flowering and grain filling stages. The booting stage exhibited the maximum dry weight (0.089 g) in PBW 752 at 4000 ppm dosage. The 4000 ppm foliar spray significantly increased the relative growth rate of PBW 725 (15 %) at Bathinda. Humic acid reduced electrolyte leakage in PBW 725 and PBW 752 plants at Bathinda, and increased cellular viability (72 %) along with leaf relative water content (99 %) at 4000 ppm foliar spray The chlorophyll a (25.84 mg g-1 FW), chlorophyll b (10.96 mg g-1 FW), total chlorophyll content (33.5 mg g-1 FW) and carotenoids (10.46 mg g-1 FW) spiked after 4000 ppm foliar spray of humic acid. The flowering stage showed an unprecedented value of total soluble sugars for PBW 725 (49.8 mg g-1 FW) on 4000 ppm treatment of humic acid. The study found that starch content (52.9 mg g-1 FW) increased significantly PBW 752 after 4000 ppm of foliar spray of humic acid. The highest α-amylase activity (133.1 nanomoles of glucose formed min-1 g-1 FW) was observed in PBW 752 at booting stage after 4000 ppm of foliar spray of humic acid. On the other hand, foliar spray of humic acid did not depict any significant effect on yield components.ThesisItem Embargo Morpho-anatomical and biochemical characterization of interspecific cotton (Gossypium spp.) derivatives for jassid tolerance(Punjab Agricultural University, 2023) Garg, Nitika; Gupta, NehaThe present investigation entitled “Morpho-anatomical and biochemical characterization of interspecific cotton (Gossypium spp.) derivatives for jassid tolerance” was undertaken to evaluate the performance of backcross derivatives carrying genomic introgressions of G. arboreum in G. hirsutum background for jassid tolerance. Various leaf morpho-anatomical characteristics such as gossypol glands, trichome density on both young and mature leaves, extrafloral nectaries, distance between lower epidermis to phloem, leaf thickness in stelar and extra-stelar region were studied in parents G. arboreum LD 491, G. hirsutum LH 2107 and their BC1F2 derivatives find out their relationship with jassid (Amrasca biguttula) tolerance on cotton. Present research revealed non-significant differences for gossypol glands and extrafloral nectaries among the parents. The backcross derivatives exhibited a wide genetic variation for gossypol glands, trichome density and other studied morpho- anatomical traits. Trichome density was significantly higher in G. arboreum (156.02±4.36) than G. hirsutum cv. LH 2107 (92.24±2.03). However, trichome counts on young and mature leaves depicted a significant decline in trichome density with maturity among parents and backcross derivatives. The backcross derivatives exhibited wide range of leaf thickness from 0.25 mm to 0.82 mm in stelar region whereas in extra-stelar regions, the BC1F2 individuals had leaf thickness from 0.09 mm to 0.30 mm. The distance between lower epidermis to phloem was highest in G. arboreum (0.26 mm) than G. hirsutum (0.23 mm). The backcross population had a range of 0.13 mm - 0.36 mm for distance of lower epidermis to phloem among the individuals. No direct relationship between above mentioned morpho-anatomical traits and jassid nymph count on was depicted in our study. In addition, various biochemicals such as chlorophyll and carotenoid, sugars, starch, gossypol, phenolic, tannins, flavonoids, lignin and salicylic acid contents of leaf tissue were also determined in G. arboreum and G. hirsutum parents and backcross population at maximum jassid infestation. Tolerant entries (belonging to Grade I and II) had significantly higher contents of chlorophyll and carotenoid, soluble sugars, total phenols, tannins, and flavonoids than susceptible group of entries (with grade IV). Starch and salicylic acid content was significantly lower in the tolerant group of genotypes than susceptible ones. Our study concluded that higher levels of the secondary metabolites (phenols, tannins, flavonoids) and maintained production of sugar assimilates might contribute towards jassid tolerance of interspecific derivatives belonging to Grade I and Grade II.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 Embargo Histological and physiological changes in developing seeds and fruit pericarp of pumpkin (Cucurbita pepo L.) grown during different seasons(Punjab Agricultural University, 2022) Bhavna; Chahal, Gagandeep KaurThe histological and biochemical changes in developing seeds and pericarp of pumpkin genotypes (hulled and hull-less) in different growing seasons were evaluated in the present study. Biochemical analysis of seed coat revealed that the proteins, lipids and starch content were decreased in the seed coat with advancement of seed development due to translocation of these components towards the seed cotyledon since cotyledon acting as dominant sink. The proteins, lipids and starch content were observed to be more in the seed cotyledon in season II (low temperature) which improved the seed quality and also increased the thickness of seed cotyledon. Further, histological studies of developing seeds also depicted that the seed cotyledon thickness was more in season II as the low temperature slowed the seed development and gave more time to seed for accumulation of biomolecules into seed cotyledon. The seed coat thickness was also found to be more in season II in both the genotypes due to increased content of primary wall components like cellulose, hemicellulose and pectin and their deposition is responsible for increasing the seed coat thickness. The seed length, diameter and hundred seed weight were also more in season II and might be caused by increased seed coat and cotyledon contents. The pectin, cellulose, hemicellulose and lignin contents were observed to be increased with development in the pericarp.The development of pumpkin seeds and fruits hastened in high temperature which decreased the seed quality, while the low temperature slowed the maturity process and enhanced the seed quality.ThesisItem Restricted Physiological and histological changes induced by Xanthomonas citri pv. punicae in pomegranate (Punica granatum L.)(Punjab Agricultural University, 2023) Komal; Nirmaljit KaurIn Pomegranate, bacterial blight is a major disease caused by Xanthomonas citri pv. punicae which leads to enormous economical losses. The objective of the present research was to analyze five pomegranate varieties against bacterial blight under field conditions; and to evaluate biochemical, physiological and histological characteristics in relation to reaction of the pomegranate varieties to the disease. Varieties of pomegranate were rated on the basis of Percent disease Index (PDI) worked out in the leaves and fruit peels and the varieties Bhagwa, Mridula and Jyoti were rated as susceptible and Jodhpur Red and Ganesh are rated as highly susceptible varieties, respectively. The stomatal frequency, stomatal size and stomatal index were significantly high in the most susceptible varieties Ganesh and Jodhpur Red. The chlorophyll a, chlorophyll b, total chlorophyll content, total carotenoid content, total soluble proteins, total soluble sugars, free amino acids, total phenols, ascorbic acid, proline and hydrogen peroxide, MDA and mineral content; and peroxidase and polyphenoloxidase were quantified from healthy and diseased leaves and fruit peels of the pomegranate varieties. The chlorophyll a, chlorophyll b, total chlorophylls and total carotenoid content were higher in the healthy leaves as compared to the diseased counterparts. These metabolites were higher in the less susceptible varieties as compared to the highly susceptible ones. Total soluble proteins, total soluble sugars, free amino acids, total phenols, ascorbic acids, total proline content and minerals were significantly higher in the susceptible variety Bhagwa and lower in the highly susceptible varieties Ganesh and Jodhpur red. The hydrogen peroxide and malondialdehyde (MDA) content was higher in the varieties Ganesh and Jodhpur Red and lower in the varieties Bhagwa. The activity of the peroxidase was high in the susceptible varieties (Bhagwa, Jyoti) and lower in the highly susceptible varieties (Ganesh), while polyphenoloxidase activity was higher in the highly susceptible varieties and lower in the susceptible varieties of pomegranate. Hence, it may be concluded that the variety Ganesh was highly susceptible to blight disease on the basis of studies conducted.ThesisItem Embargo Constitutive Defence Response In Cucumber (Cucumis Sativus L.) Against Downy Mildew(Punjab Agricultural University, 2023) Samarveer Kaur; Ghai, NavitaThe present study was conducted to assess the constitutive defence response in cucumber (Cucumis sativus L.) against downy mildew. Plants of two varieties Kheera No.1 and Punjab Naveen were artificially inoculated at three leaf stage using conidial suspension by spray inoculation method. On the basis of disease severity index (Jenkins scale), variety Kheera No.1 was found to be moderately resistant while Punjab Naveen as moderately susceptible. Stomatal and trichome characteristics were conducted to determine the structural variation on 8th day after inoculation and stomatal characteristics were found to be higher in variety Punjab Naveen on both adaxial and abaxial surface of leaf, but trichome size and frequency was higher in variety Kheera No. 1 as compared to variety Punjab Naveen. A decrease in total chlorophyll content and electrolyte leakage was recorded in inoculated plants of both the varieties from 2 to 12 days after inoculation, but there was more decrease in variety Punjab Naveen as compared to Kheera No.1. Post infection, a decrease in total soluble sugar content was recorded in both the varieties. However, an increase in total soluble proteins, total phenols, total flavonoids, ascorbic acid was exhibited with more enhancement in Kheera No.1 in contrast to Punjab Naveen. The activities of various enzymes viz., Polyphenol oxidase (PPO), Peroxidase (POD), Phenylalanine ammonia lyase (PAL) and Superoxide Dismutase (SOD) was found to increase in inoculated plants of both the varieties as compared to their respective uninoculated plants. Based on anatomical studies, there was more increment in total leaf thickness, spongy and palisade tissues in cultivar Punjab Naveen in contrast to Kheera No.1. However, phylloplane morphology, enhanced level of antioxidants (enzymatic and non-enzymatic), total soluble proteins and decline in level of total soluble sugars, post infection, helped in conferring moderate resistance to the pathogen infection in variety Kheera No.1.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 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.
