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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 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 Studies on growth and reproductive efficiency of transplanted rice (oryza sativa L.) in relation to seedling age and growth regulators(Punjab Agricultural University, Ludhiana, 2019) Kawatra, Anjali; Ghai, NavitaThe time of transplanting is an important factor for efficient vegetative growth, grain quantity and quality in rice.The present investigation” Studies on growth and reproductive efficiency of transplanted rice (oryza sativa L.) in relation to seedling age and growth regulators” was planned with an objective to study the effect of kinetin and triacontanol on morpho- physiological, phenological and yield parameters of PR126 variety of rice transplanted using aged seedlings. Seed of variety PR126 were sown in the nursery during last week of May 2018.The crop was transplanted at two stages i.e 30 days after sowing (normal) and 45 days after sowing (aged). Foliar application of kinetin (@ 10,20,30 ppm) and triacontanol (@1,2 & 4 ppm) was done at two stages i.e nursery stage ( 1 week before transplanting ) and crop stage (1 week after transplanting. Unsprayed plants were considered as control. Application of 4 ppm triacontanol at nursery + crop stage resulted in maximum tiller number, dry matter translocation efficiency and contribution of pre anthesis dry matter assimilates to seeds which in turn enhanced the crop yield. The application of 30 ppm kinetin at nursery stage resulted in increased number of filled grains per panicle,total number of grains per panicle and harvest index of the crop.Also application of 30 ppm kinetin at nursery + crop stage resulted in increased dry matter partitioning to all the parts which as a result increased the grain yield of the crop. Thus, if older seedlings of rice are to be used the productivity enhancement can be achieved through the foliar application of either kinetin 30 ppm or TRIA 4 ppm on nursery(one week before transplanting) and/or crop ( 1 week after transplanting)ThesisItem Open Access Physiological basis of host resistance against bakanae disease of rice (Oryza sativa L.)(Punjab Agricultural University, Ludhiana, 2019) Chhabra, Rohit; Nirmaljit KaurThe present study to understand the basis of disease tolerance in rice cultivars was performed on two aromatic (PUSA 1121 and PUSA 1509) and two non-aromatic (PR 121 and PR 126) cultivars in field area, laboratory of Department of Botany and Seed Pathology laboratory, Punjab Agricultural University, Ludhiana (Punjab). The seeds of the experimental rice cultivars were inoculated with virulent isolate of Fusarium fujikuroi obtained from seed Pathology laboratory. The first experiment was to study the biochemical and anatomical traits associated with development of bakanae in seedlings under laboratory conditions. The second experiment dealt with the field reaction and associated metabolic changes in nursery grown seedlings. The third experiment was further divided in two sections, firstly to study the effect of inoculation of rice seeds with F. fujikuroi on their vigour, and the second part highlights the variation in biochemical machinery of the rice seeds 48 hours after inoculation. Reduction in percent germination and fresh and dry weight of seedlings was observed in both aromatic and non-aromatic rice cultivars post inoculation, the variation being significant in aromatic cultivars. Seed inoculation with the fungus resulted in a significant increase in length of the infected seedlings in aromatic rice cultivars as compared to non-aromatic ones possibly due to significant enhancement of endogenous gibberellic acid post infection in the aromatic rice seedlings. The chlorophyll a, b and total chlorophyll, total soluble sugars and starch content was higher in healthy seedlings, while carotenoids and alpha amylase activity was higher in infected seedlings of both aromatic and non-aromatic rice cultivars. Total phenols, orthodihydric phenols and total soluble proteins were higher in non-aromatic rice seedlings post infection indicating the initiation of defence mechanism against the pathogen. Increase in activity of peroxidase, superoxide dismutase, polyphenol oxidase and antioxidant activity in aromatic rice cultivars post infection indicate the biotic stress created by pathogen. Histopathological observations revealed hyphal and conidial growth in infected tissues of aromatic cultivars whereas a complete and intact tissue was observed in healthy and infected counterparts of non-aromatic cultivars. The induction of activity of antioxidant enzymes in aromatic rice seeds post inoculation could be effectively exploited to screen the tolerance potential of aromatic rice cultivars against bakanae disease.