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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 Effect of biochar and bacterial endophytes on salinity tolerance in oats (Avena sativa L.)(Punjab Agricultural University, 2023) Arshdeep Kaur; Gupta, NamartaThe present investigation was carried out to study the effect of biochar and plant growth-promoting bacterial endophytes for salt tolerance in oats (Avena sativa L.). Forty four morphologically distinct salinity-tolerant endophytic bacteria were isolated from the leaf, stem and root samples of oats on nutrient agar with 2.5% NaCl and screened for the production of ammonia, auxins, siderophore and HCN; solubilization of Ca3(PO4)2, ZnO, Zn3(PO4) and ZnCO3 and salt tolerance up to 12% NaCl. Bacterial isolates showing high salt-tolerance and plant growth-promoting traits were selected and tested for growth promotion of oats on 1% H2O agar plates. Three potential isolates were identified based on polyphasic approach as Enterobacter quasiroggenkampii O1SE4, Bacillus inaquosorum O3SE2 and Bacillus safensis O4SE1. The SEM analysis showed the colonization of the plant tissues by all the three bacterial strains. Total 25 genotypes were screened for germination parameters viz. percent germination, shoot length, root length, seedling length, fresh weight, dry weight, vigour index I and II, proline, SOD, POD and CAT under salt stress conditions and were grouped into highly salt tolerant, moderately salt tolerant, moderatly salt sensitive and highly salt sensitive. Among seed treatments, the combination of biochar (2%) and Bacillus safensis maximally improved the above parameters as compared to the other treatments of Enterobacter quasiroggenkampii, Bacillus inaquosorum and biochar (1%). The evaluation of biochar and bacterial strains was done in two salt tolerant and two salt sensitive genotypes grown in the pots. The highest plant height, SLW, NAR were observed with the bacterial treatment (Bacillus safensis) + biochar (2%). Among biochemical parameters chlorophyll, carotenoid, total soluble sugar, starch, total soluble protein and free amino acids along with activities of antioxidant enzymes SOD, POD and CAT were enhanced by the application of Bacillus safensis and biochar (2%). Na+/K+/Ca2+/Mg2+ homeostasis was maintained by biochar and bacteria application. In conclusion, it is stated that the combined use of biochar and halotolerant endophytic bacteria can be used for improving the crop growth under salt stress in oats.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 Embargo 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, 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 accumulation 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 (<55%) even at higher concentrations of Pb300 and Cd25. The accumulation of proline, total soluble sugars, total soluble proteins along with increased antioxidant enzyme activities are responsible to enhance tolerance in both species. On the basis of phytoremediation efficiency evaluation factors such as bioconcentration factor (BCF) and translocation factor (TF), Salix alba can be categorized as excluder plant for Pb and Cd with higher metal accumulation in roots than shoots (BCF>1, TF<1), while Toona ciliata can be categorized as hyperaccumulator with more Pb and Cd accumulation in the shoots than roots (BCF>1 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 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 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.
