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ThesisItem Open Access Effect of wheat semi-dwarfing gene Rht8 on nitrogen uptake and utilization under contrasting nitrogen treatments(Punjab Agricultural University, Ludhiana, 2019) Kulveer Kaur; Seema BediStudies on agronomic and morpho-physiological parameters associated with nitrogen use efficiency (NUE) are important for developing high-yielding genotypes and sustaining yield levels. The present study entitled “Effect of wheat semi-dwarfing gene Rht8 on nitrogen uptake and utilization under contrasting nitrogen treatments” was conducted at the experimental area of wheat section, Department of Plant Breeding and Genetics and Department of Botany, Punjab Agricultural University (PAU), Ludhiana during rabi season of 2017-18 and 2018-19. Field experiment on 34 genotypes introgressed with a dwarfing gene Rht8 were evaluated in three N regimes viz., 125Kg ha-1, 62.5Kg ha-1 and unfertilized plots (no nitrogen) taken as control. Various agronomic and morpho-physiological traits under three N regimes were recorded to assess the effect of dwarfing gene Rht8 on root architecture or on nitrogen use efficiency (NUE) of the genotypes. The results revealed that gene Rht8 has a positive role in NUE as observed through agronomic and morpho-physiological traits. Significant differences in grain yield, yield attributes, N uptake and NUE were observed among genotypes having gene Rht8 and the control genotypes without the dwarfing gene. The gene can be used in wheat breeding program for improving NUE and also ensuring less use of fertilizers and environment friendly agriculture. The gene Rht8 has a strong effect on N uptake via improved root vigour and depth. This improvement in root system may also be explored for tolerance to other abiotic stresses, specifically drought conditions.ThesisItem Open Access Physiological biochemical and molecular parameters of salt tolerance in different genotypes of oats (Avena sativa L.)(Punjab Agricultural University, Ludhiana, 2019) Kamaljeet Kaur; Gupta, NamartaThe effect of salt stress was studied on physiological, biochemical and molecular parameters in different genotypes viz. Kent, OL-10, OL-1862, OL-1869, OL-125, OL- 1966, OL-1876, OL-1895 of oats (Avena sativa L.). When seeds of oats were subjected to different salt concentrations ( at 25mM, 50mM, 75mM, 100mM, 125mM, 150mM, 175mM, 200mM) of NaCl, various physiological parameters such as shoot length(lamina and sheath), root length, dry weight, fresh weight, seed vigour I, seed vigour II declined with the increase in salt stress level in all the genotypes whereas the biochemical parameters such as total soluble sugars, total protein content and activities of antioxidant enzymes increased with the increase in salt stress level in all genotypes.ThesisItem Open Access Physiological, biochemical and molecular parameters of salt tolerance in different genotypes of barley (Hordeum vulgare L.)(Punjab Agricultural University, Ludhiana, 2019) Goyal, Priyanka; Gupta, NamartaIn the present investigation, the influence of salt stress on physiological, biochemical and molecular parameters in barley (Hordeum vulgare L.) genotypes at different salinity levels was studied. Seeds of ten barley genotypes (BL1400, BL1314, PL890, PL807, RD2552, PL751, BL1430, PL426, BL1375 and BL1367) were treated with different salt concentrations (0, 25, 50, 75, 100, 125, 150, 175 and 200 mM NaCl). The salinity stress has deleterious effect on seed germination and seed vigour parameters. Increased salinity caused a significant reduction in percentage of germination and seed germination rates. Also, a significant reduction in root and shoot length of seedlings was recorded. Seedling biomass (fresh and dry weight) declined in stressed seedlings as compared to control. Among all salt concentrations effect of salt stress was more differentiable at 75mM and 100mM. Therefore, these salinity levels were selected to test the effect of salt stress on biochemical parameters. All biochemical parameters viz. total soluble sugar content, total soluble protein content and activity of antioxidant enzymes (catalase, peroxidase and superoxide dismutase) increased with increased salt stress. Also, molecular studies were conducted on comparatively sensitive and comparatively tolerant genotype under selected salt concentration levels.ThesisItem Open Access Overcoming seed dormancy in round gourd (Praecitrullus fistulosus (Stocks) Pangalo) with different storage durations and priming treatments(Punjab Agricultural University, Ludhiana, 2019) Tavisha Singh; Bedi, SeemaThe round gourd (Praecitrullus fistulosus (Stocks) Pangalo) seeds are characterized by hard seed coat. Under Punjab conditions, the seeds are harvested in mid-June and used for sowing in the months of June and July. The round gourd seeds exhibit dormancy soon after harvesting. However, the objective of the present study was to standardize priming treatments that would break the dormancy in seeds obtained from freshly harvested fruits of round gourd. The seeds, immediately after harvest, were stored at 250C for 0, 15, 30, 45 and 60 days respectively. The stored seeds were subjected to various priming treatments viz., seed soak in GA3 (150μgml-1, 500 μgml-1, 1000 μgml-1 gibberellic acid), cytokinin (150μgml-1, 500μgml-1, 1000 μgml-1 kinetin), ethylene (150 μlL-1, 500 μlL-1, 1000 μlL-1 ethrel), KNO3 (150μgml-1, 500 μgml-1), HNO3 (150 μlL-1, 500 μlL-1) and water (hydropriming) for 12 and 24 h respectively at 250C. The germination potential and various germination related parameters increased with an increase in storage duration with maximum value in seeds stored for 60 DAH although the 60 % germination barrier is crossed in seeds stored for 45 DAH. Among all the priming treatments, priming with 500μgml-1 KNO3 for 12 h (T22) was the only treatment that improved percentage germination, coefficient of rate of germination (CRG) and reduced mean days to germination (MDG) in the freshly harvested seeds (0 DAH). An enhancement in biochemical parameters, viz., total soluble sugars, total starch, total soluble protein, total free amino acids and α-amylase content was observed. However, priming in GA3 though was less than KNO3 in enhancing germination related parameters but was at par with KNO3 with respect to improvement in biochemical parameters.ThesisItem Open Access Effect of nitrate and ammonium ratios on physiological and quality attributes of hydroponically grown leafy vegetables(Punjab Agricultural University, Ludhiana, 2019) Ratnesh Kumari; Bedi, SeemaThe effect of variable NO3 -to NH4 + ratios in the nutrient solution was evaluated on growth, nutritional quality and yield attributes of hydroponically grown leafy vegetables. Spinach (cv. Punjab Green), Coriander (cv. Punjab Sugandh) and Lettuce (cv. Iceberg) grown under substrate hydroponics with intermittent supply of water and nutrients. Simultaneously crop was raised in open field by conventional practices. Crop was sown on three dates viz., October (main season) and February and July (off-season) respectively. N was supplied in variable ratios of NO3 - to NH4 + viz., 100:0 (T1), 75:25 (T2), 50:50 (T3), 25:75 (T4), 0:100 (T5) respectively, keeping total N content constant. Fresh foliage was harvested 3 times in each season from each respective treatment at 30 days interval starting from date of sowing. At each harvesting, growth (fresh and dry biomass of shoot and root, plant height, leaf area and total yield per plant), quality parameters (total chlorophyll, carotenoids, soluble sugars, starch, soluble proteins, free amino acids and proline) and antioxidant enzyme activities (SOD, CAT, and POD) were determined. During all the three seasons, the yield was significantly more in hydroponically than open field sown crop. Under substrate hydroponics, maximum yield was obtained in the plants provided with nutrient solution T2 (NO3 - : NH4 +:: 75:25) and also had higher values of quality parameters and highest antioxidants activities than the open field crop. It is suggested that NO3 - to NH4 + ratio of 75:25 improve the growth, antioxidants activity, quality attributes and is thus most suitable for leafy vegetables growth under substrate hydroponics.ThesisItem Restricted Evaluation of packaging material for improvement in keeping quality of marigold (Tagetes erecta L.) flowers(Punjab Agricultural University, Ludhiana, 2019) Verma, Tunisha; Jhanji, ShaliniThe present investigation entitled “Evaluation of packaging material for improvement in keeping quality of marigold (Tagetes erecta L.) flowers” was conducted in the Department of Floriculture Landscaping and Department of Botany, Punjab Agricultural University, Ludhiana during the year 2018-19. The harvested flowers of marigold var. Punjab Gainda No-1 and Jafery were placed in different packaging materials (polythene, CFB box, ice box, bamboo basket, gunny bag and onion mesh bag) for different storage durations (0,1,2 and 3 days). After different treatments, the keeping quality of flowers under ambient conditions during summer, rainy and winter season was evaluated. The shelf life of marigold var. Punjab Gainda No-1 was recorded to be 1 day in summer season and 4 days in rainy season whereas Jafrey had shelf life of 3.66 days in rainy season and 6.00 days in winter season when stored in ice box. Highest shelf life was recorded in Jafery during winter season as compared to Jafrey in rainy season and Punjab Gainda No-1 in summer and rainy season which was supported by high membrane stability index, relative water content, total soluble protein content, total soluble sugar content, lesser loss in physiological weight, minimum spoilage and maximum freshness index of flowers in winter season. Comparison of two varieties in rainy season revealed better performance of Punjab Gainda No-1 than Jafrey in terms of all post-harvest quality, physiological and biochemical parameters. Among all the packages, ice box, CFB box and polythene packages showed better results in comparison to gunny bag and onion mesh bag. In regard to storage duration, one day storage was better in comparison to two and three days in all the seasons. The results pertaining to physiological and biochemical analysis supported the results of keeping quality parameters. Thus, marigold flowers can be packed in ice box, CFB box and polythene for 1 to 2 days without any adverse effect on keeping quality during rainy and winter season but only for 1 day during summer season with slight effect on its keeping quality.ThesisItem Open Access Deciphering the sulphur assimilation pathway in biofortified wheat and its relationship to zinc transport(Punjab Agricultural University, Ludhiana, 2019) Arshdeep Kaur; Gupta, NehaThe present field research entitled “Deciphering the sulphur assimilation pathway in biofortified wheat and its relationship to zinc transport” was conducted in split-split plot design during rabi seasons of 2017-18 and 2018-19. The main plot treatments were- control (no zinc) and high zinc conditions, where soil application of ZnSO4 was done at sowing. The wheat cultivars PBW 1Zn and PBW 725 acted as sub plots. The sub-sub plot treatments include: i) Control, ii) foliar application of 0.5% ZnSO4, iii) foliar application of sulphur (S) @ 0.06%, iv) soil application of S at sowing followed by foliar S application same as (iii). Foliar application of chemicals in different treatments was done at earing and milking stage of crop. Rate of S application (in soil and foliar spray) was given as per S dose provided by ZnSO4 in present agronomic biofortified trail. Soil Zn application did not affect emergence count/m2 and percent moisture content of wheat crop at earlier growth stages. But there was a significant increase in cysteine content, Zn and S concentration of flag leaf and other tissues (peduncle and developing grain) at earing and milking stage under high Zn condition than the control. Among the varieties, PBW 1Zn had higher concentration of cysteine, Zn and S than PBW 725. In contrast to Zn, Fe concentration was found to be declined under high Zn conditions on significant basis. Further genetically biofortified PBW 1Zn exhibited significantly low Fe content than PBW 725 at periodic intervals. High soil Zn conditions and 0.5% foliar Zn spray was found to enhance grain yield by 4-11%. Among varieties, grain yield was significantly higher in PBW 725 which was due to more number of tillers and 1000 grain weight. Highest grain Zn content was observed in PBW 1Zn with 0.5% foliar ZnSO4 spray under high Zn conditions. Biochemical analysis in present study clearly showed that 0.5% ZnSO4 foliar treatment had higher Zn contents in flag leaf, peduncle and developing grain at successive stages of grain development and was also be able to enhance grain Zn significantly than other foliar treatment. Although soil S + foliar S application or foliar S alone had lower grain Zn than 0.5% ZnSO4 treatment; but this was significantly higher than control plants. Moreover increment in Fe content of developing grain with soil S + foliar S was significantly higher than 0.5% ZnSO4 and control plots. Non-significant differences were observed for quality parameters such as grain hardness, gluten content, gluten index under different soil Zn conditions. The variety PBW 725 had significantly higher gluten content than PBW 1Zn. Although the later variety contained more grain Zn than PBW 725. Present research clearly depicted an antagonistic crosstalk between Fe and Zn uptake and their translocation in biofortified wheat which modifies upon interaction with sulphur supply.ThesisItem Open Access Influence of corm treatments with benzyl adenine and gibberellic acid on post harvest keeping quality of gladiolus (Gladiolus grandiflorus L.)(Punjab Agricultural University, Ludhiana, 2019) Gaur, Kompal; Jhanji, ShaliniThe present investigation entitled “Influence of corm treatments with benzyl adenine and gibberellic acid on post harvest keeping quality of gladiolus (Gladiolus grandiflorus L.)” was carried out in Research Farms of Floriculture and Landscaping and Laboratories of Botany, Punjab Agricultural University during the year 2018-19. The corms of gladiolus varieties Punjab Glance and Priscilla were dipped for 24 hours in freshly prepared solutions of different concentrations (50 mg l-1, 75 mg l-1, 100 mg l-1 and 125 mg l-1) of benzyl adenine (BA) and gibberellic acid (GA3). The maximum increase in plant height, spike length, leaf area and leaf weight was recorded with 125 mg l-1 GA3 whereas corresponding values were least with 125 mg l-1 BA. The chorophyll content, membrane stability index, relative water content, total soluble sugars and total protein content in leaves and florets of gladiolus increased with increasing concentrations of BA and GA3. The post harvest quality parameters also improved with BA and GA3 treatments as compared to control but GA3 had more pronounced effect than BA. The treatment with 125 mg l-1 GA3 significantly hastened the opening of basal floret, increased floret size, number of florets open at one time, per cent opening of florets, water absorbed and decreased pH that ultimately led to improvement in vase life. The days taken to open basal floret were maximum in BA treatments as compared to all other treatments. Therefore, both BA and GA3 improved vase life but 125 mg l-1 GA3 increased the vase life (15.16) to maximum among all treatments. The treatment of corms with 125 mg l-1 BA resulted in maximum enhancement in production of corms (3.33), cormels (15.83) and spikes per corm (2.83). Thus, 125 mg l-1 GA3 was most efficient in improving vegetative growth and post harvest quality parameters whereas 125 mg l-1 BA was efficient in improving corm and cormel production.ThesisItem Open Access Morpho-physiological and biochemical characterization of a recombinant inbred line population of rice (Oryza sativa L.) under direct-seeded aerobic conditions(Punjab Agricultural University, Ludhiana, 2014) Cheema, Amandeep Kaur; Bedi, SeemaDirect seeding of rice (Oryza sativa L.) is a resource conservation technology but at the cost of reduction in yield. In the present study, recombinant inbred lines (RILs) obtained from a cross between PR 120 x UPLRi 7 were sown as direct-seeded aerobic and conventional transplanted crops respectively for two seasons. Various morpho-physiological, biochemical and yield related traits were studied under the two conditions. In general, plant height, dry matter, crop growth rate, relative growth rate, leaf area and chlorophyll content were lower under direct-seeded aerobic conditions than under conventional transplanted conditions. Plant height and crop growth rate showed a positive correlation with grain yield and had a direct effect on grain yield. Dry matter accumulation did not show any significant correlation but had an indirect effect on grain yield. Relative growth rate, leaf area and chlorophyll content did not show any correlation or effect on grain yield. All the yield contributing traits viz., above ground biomass, total number of tillers per 0.5m row, number of fertile tillers per panicle per 0.5m row, spikelets per panicle, grain filling percentage, grain yield per 0.5m row, harvest index, 1000 grain weight were lower and sterile grain per panicle were higher in direct-seeded aerobic condition. Above ground biomass and harvest index showed correlation with yield and had a direct effect on grain yield under both direct-seeded aerobic and conventional transplanted conditions. In general, higher sugar, starch and proline content were detected in leaves of direct-seeded aerobic crop. Out of twenty RILs under study, Ae-RIL-B-158, showed highest proline and sugar contents. Interestingly, this RIL showed least reduction in yield when sown under direct seeded-aerobic condition as against conventional transplanted condition suggesting this RIL may be more tolerant to drought stress as it accumulated highest proline and sugars under direct-seeded aerobic condition. The development of aerenchyma was comparatively more in crop raised under conventional transplanted conditions than under direct-seeded aerobic conditions. UPLRi7 (parent) showed maximum aerenchyma under direct-seeded aerobic conditions while PR120 (parent) showed maximum aerenchyma formation under conventional transplanted conditions. Under both the sowing conditions, two high-yielding RILs (Ae-RIL-B-42 and Ae-RIL-B-44) had higher aerenchyma than the two low-yielding RILs (Ae-RIL-B-7 and Ae-RIL-B-117). These characters could be used as criteria for selecting RILs for incorporating into breeding programmes for yield enhancement.