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ThesisItem Embargo Effect of glutathione, proline and magnesium sulphate on seed vigour and antioxidants in sorghum (Sorghum bicolor [L.] Moench) under salt stress conditions(Punjab Agricultural University, 2024) Maheshwari, Akshita; Dr. Namarta GuptaIn the present investigation, effect of glutathione, proline and magnesium sulphate was studied on seed vigour and antioxidant defense system under salt stress conditions in sorghum (Sorghum bicolor [L.] Moench) cvs. SL 45 and SL 46. The salt stress had adverse effects on seed germination and seed vigour parameters. Seeds of sorghum were treated with proline (25ppm, 50 ppm and 100 ppm), glutathione (100 ppm, 250 ppm and 500 ppm) and magnesium sulphate (10 ppm, 25 ppm and 50 ppm) and were subjected to salt stress of 50 mM and 75 mM. Different parameters were recorded from seedlings after 10 days of germination. The seed treatments increased the physiological (percent germination, seedling length, seedling biomass, vigour index I and II) and biochemical parameters (total soluble sugars, total soluble proteins, proline content and activities of antioxidant enzymes viz. catalase, peroxidase and superoxide dismutase) of seedlings as compared to control. However, malondialdehyde content decreased with seed treatments at all salinity levels in both the cultivars. The results showed that proline 100 ppm, glutathione 500 ppm, magnesium sulphate 50 ppm were more effective than proline (25 ppm, 50 ppm), glutathione (100 ppm, 250 ppm), magnesium sulphate (10 ppm, 25 ppm) respectively. Thus, the application of proline, glutathione and magnesium sulphate could play an important role in improving the salt stress tolerance by their osmoprotective role.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 Embargo Seed treatment studies for improving seed germination and vigour in quinoa (Chenopodium quinoa Willd.) genotypes(Punjab Agricultural University, 2024) Rajvir Singh; Dr. Navjyot KaurThe present study entitled „Seed treatment studies for improving seed germination and vigour in quinoa (Chenopodium quinoa Willd.) genotypes‟ was conducted in the Plant Physiology Laboratory, Office of Director (Seeds), Punjab Agricultural University, Ludhiana during 2022-2023. In this study, fifty quinoa genotypes were screened for germination parameters i.e. germination (%), seedling length, seedling fresh weight, seedling vigour index I and II, mean germination time and speed of germination using “between-paper” method. One genotype namely EC 896071 recorded the highest germination i.e. 83.8%. Other genotypes which exhibited germination higher than 40% were EC-896076 (70.5%), EC- 896063 (53.3%), EC-896081 (53%), EC-507739 (43.8%), and EC-896091 (42.5%). Majority of genotypes (44) recorded germination in the range of 8.5-40%. On the basis of performance in Experiment I, six quinoa genotypes viz., EC-507739, EC-896063, EC-896071, EC-896076, EC-896081 and EC-896091 were selected for seed treatment studies for enhancing the germination and seedling vigour. In Experiment II, seed treatments were given to seed by priming and scarification methods i.e. hydro-priming, halo-priming, hormo-priming, acid scarification and hot water scarification. Hydropriming for 2 hrs recorded the highest improvement in mean germination time, speed of germination, germination (%), seedling vigour index I and II. From this study, 2 hour soaking of seed was standardized for other seed treatments also. Seeds were also primed with Mg(NO3)2, KNO3, KH2PO4, H2O2, CaCl2, K2HPO4, ZnSO4, GA3, kinetin, ethrel and scarified with 5% H2SO4 and hot water. A comparison of hydropriming with all other chemical and scarification treatments revealed that hydropriming with 2 hour duration is the best treatment for improving germination and vigour of quinoa genotypes.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 Embargo Growth and physiological characters in staygreen wheat introgression lines under post anthesis drought stress(Punjab Agricultural University, 2022) Shelly; Bedi, SeemaClimate change is a significant threat to the majority of agricultural crops around the world. In wheat, drought stress at post-anthesis stage is known to affect the yield and yield attributes. Genotypes with stay green trait retain the chlorophyll for longer duration and have a positive association with yield attributing traits particularly in crops experiencing abiotic stress. In this study, some stay green introgression lines were evaluated for germination under water stress conditions and yield and yield related traits under post-anthesis drought stress Under laboratory conditions, the genotypes were screened by creating drought stress using PEG 6000. The genotypes were analyzed on the basis of germination percentage, shoot length, root length, root: shoot ratio, seedling fresh and dry weight, seedling relative water content and vigour index. The genotypes BWL 4421, BWL 4423, BWL 4431 and BWL 4435 performed well. In the field the genotypes were analyzed on the basis of yield and yield attributing traits. The genotypes BWL 4431 and BWL 4435 performed well in the laboratory experiment as well as in the field experiment. Overall, the stay green lines performed better than the non-stay green check (Unnat PBW 550) in yield attributing traits and also yield by maintaining yield and other components.ThesisItem Restricted Fertilization Barriers In Interspecific Hybridization Between Cucurbita Pepo L. And Cucurbita Moschata Duchesne(Punjab Agricultural University, 2023) Kapoor, Ishita; Chahal, Gagandeep KaurThe hybridization barriers in Cucurbita moschata (Punjab Nawab, Punjab Sardar) and Cucurbita pepo (PMK-1) genotypes were investigated in the present study. The results revealed that the pollen grains were viable and stigmas were receptive at the time of pollination in all the genotypes. The maximum pollen germination (%) was observed in Punjab Nawab, while maximum viable pollen size, pollen tube length and longest style length was recorded in Punjab Sardar. Since, the shorter pollen tubes of PMK-1 did not grow enough in the longer style of Punjab Sardar, hence the interspecific cross of Punjab Sardar ×PMK-1 was incompatible. While in the reciprocal cross (PMK-1×Punjab Sardar) formation of callose plugs in the pollen tubes of Punjab Sardar and its slow growth might had contributed to the failure of fertilization. However, in the interspecific cross of Punjab Nawab × PMK-1 and vice-versa the pollen grains successfully germinated and pollen tubes reached the style, hence the cross was partially incompatible but embryo was not able to attain a particular shape. The fruit setting (%), fruit diameter, fruit weight, seed number, seed weight and seed germination (%) was lesser in interspecific crosses as compared to self-pollinated genotypes. Further, cluster analysis revealed that partially compatible and incompatible crosses are present in different clusters and partially compatible cross showed strong positive correlation with fruit characters. The information of fertilization barriers would be helpful for the breeders to overcome these barriers and introgress the hull-less seed trait of C. pepo and diseases resistant trait of C. moschata.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 Physiological and biochemical changes in asian pears (Pyrus pyrifolia L.) during ethylene induced ripening(Punjab Agricultural University, 2023) Mukherjee, Purba; Nirmaljit KaurThe present study entitled, “To study the effect of ethylene induced ripening on biochemical and physiological changes in Asian pears (Pyrus pyrifolia L.)” was carried out at Fruit Research Farm, Department of Fruit Science and Laboratories of Department of Botany, PAU, Ludhiana with the objective to decipher the optimum stage of harvest and role of ethylene on metabolic changes during fruit ripening in pear cultivars. For this, fruits of pear cultivar Patharnakh (PyruspyrifoliaBurm.F. Nakai), Punjab Beauty (Pyruspyrifolia× Pyruscommunis), Yali (PyrusbretschneideriRehd.) and Nijisseiki (Pyruspyrifolia) were examined during the fruiting season of 2022-2023. The fruit firmness, its total soluble solids, titratable acidity, flavonoid content and total sugar analysis revealed that with storage interval, the fruit firmness, titratable acidity and flavonoids declined in all cultivars; and among these, ethrel treatment reduced the firmness of fruits, titratable acidity and flavonoid content. However, total soluble solids and soluble sugars exhibited a surge from 0-5 days and declined thereafter and the ethylene treatment increased their level. The pectin, lignin and cellulose content & the cell wall degrading enzymes pectin methylesterase (PME), polygalacturanase (PG) and cellulase were analysed in the peel and pulp separately. The pectin and cellulose content declined with storage in both peel and pulp, whereas lignins increased with storage. The ethylene treatment declined the pectin and cellulose in both peel and pulp; however lignin content increased in peel as well as in pulp with ethrel. The PME showed a surge from 0-10 days and declined thereafter in peel and pulp with increase in storage duration, but in pulp another increase after 10 days storage was observed. However, the ethylene treatment increased the activity of all these enzymes. The activity of sorbitol dehydrogenase, sorbitol oxidase and acid invertase was assessed in the fruits; in all pear cultivars the activity of these sugar metabolizing enzymes declined with storage interval as well as with ethylene treatment. The MDA content increased with advance in storage duration from 0 days to 15 days and ethylene increased MDA content at all the days of storage in all pear cultivars assessed. Among all the four pear cultivars major degradation of fruit pericarp was observed in cultivar Punjab Beauty (Semi-soft pear) with increasing storage days and after ethrel treatment, whereas the cultivar Patharnakh (Hard pear) was observed to reach a more palatable texture on storage and ethrel treatment induced uniform ripening in them. The fruits of cultivars Nijisseiki, and Yali (Soft pears) did not deteriorate with storage as well as with ethrel treatment. Moreover, cell wall degrading enzymes were highest in Punjab Beauty, followed by Yali and nijisseiki and least activity was recorded in Patharnakh. Hence, it may be concluded that the pear cultivars viz., Patharnakh, Yali and Nijisseikki can be stored for ten days at 20°C and 70 % RH for uniform ripening. The semi soft pear cultivar Punjab Beauty had very high activity of cell wall degrading enzymes (unlike the soft pears) so it is suggested that this cultivar attains edible maturity by five days.
